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Comments 130701 to 130750:

130701. Patrick 027 at 11:46 AM on 9 November 2008
        Arctic sea ice melt - natural or man-made?
        Clarifications: ..."there is a process of geostrophic adjustment which radiates mechanical waves" - I think this generally involves radiating waves with frequencies greater than f/(2pi) - and would not involve Rossby waves (?), which are not fundamentally ageostrophic but rather 'quasi-geostrophic'. Of course Rossby waves may be produced but they do different things. "When the AV is anticylonic, there is inertial instability; this is an instability in horizontal motion." - with static stability, there is the buoyancy frequency N. When the square of N is negative (there's a mathematical formula with the square of N), N is imaginary; an imaginary frequency corresponds to instability, whereas neutral stability corresponds to N = 0. A real nonzero N occurs when the air is stable, meaning potential temperature increases with height; an adiabatic vertical displacement involves pulling or pushing up or down on an isentropic surface, creating a thermal anomaly whose buoyancy tends to push the isentropic surface bump or dent back. - with inertial stability, a horizontal displacment of air may put it in a location surrounded by air with different velocity. This is true when the velocity varies horizontally, so that there might be vorticity. Because the air parcel has a different velocity, while it is in the same pressure field as the air immediately next to it (for a small parcel), it has a different acceleration due to the coriolis effect, so it tends to move differently than it's surroundings. The effect is to push it back to where it was taken from, and so it can oscillate with a frequency; but when that frequency is imaginary, there is instability - the acceleration due to the coriolis effect acting on the different velocity actually pulls it farther away from it's initial position in that case. ---- Streamfunction: Streamlines, which are everywhere parallel to the non-divergent component of the wind, are actually contours of the streamfunction. Each component of the wind can have it's own streamfunction and they can be linearly added to give a total streamfunction for the total non-divergent wind (streamfunctions can't be defined for divergent winds). The streamfunction for the geostrophic wind is defined, in isobaric coordinates (x,y,p) as the geopotential (or the geopotential minus some average spatially-invariant geopotential) on an isobaric surface divided by f. Actually, though, because f varies with latitude, the geostrophic wind has a divergent component if there is any north-south velocity component, so the streamfunction as just defined is only approximate and I'm not sure if the streamlines would be everywhere parallel to the geostrophic wind in that case; one way around that is to pick some basic state f, f0, which is the value of f at some latitude where y is arbitrarily equal to zero, and use that to define the streamfunction; the actual f is then equal to f0 + y*beta (if beta is constant, which is also an approximation valid for some finite range of latitudes centered on y=0 - this approximation is referred to as a 'beta plane'). The effect of the variation in f is then incorporated into the equations as y*beta, etc. The streamfunction on an isentropic surface is the Montgomery streamfunction, which is equal to cp*T + geopotential (or that minus any constant) - where cp is the heat capacity per unit mass, and T is the temperature. Along an isentropic surface (both in space and time), T only varies as a function of p (pressure) (adiabatic temperature changes). Thus where an isentropic surface is parallel to an isobaric surface (the same condition where there is no vertical geostrophic wind shear), the Montgomery streamfunction is just proportional to the isobaric streamfunction. The cp*T term accounts for the variation of geostrophic wind with height in isobaric coordinates. At any given intersection of an isobaric surface and an isentropic surface (which is an isotherm on the isobaric surface or an isobar on the isentropic surface), the wind is the same; the difference in geostrophic velocity between two isobars on an isentropic surface is due to the sum of 1.the change in geostrophic velocity along an isobaric surface some horizontal distance, and 2.the change in geostrophic velocity that occurs going vertically from that isobaric surface back to the isentropic surface. The later is perpendicular to the slope of the isentropic surface in (x,y,p) coordinates...[**?? Notice that the geostrophic wind, if not for non-zero beta, would be non-divergent on an isentropic surface as well as on an isobaric surface (I think **).] The curvature of the streamfunction, or specifically, the Laplacian of the streamfunction, is proportional to the relative vorticity. The Laplacian is equal to the divergence of the gradient.
130702. Patrick 027 at 06:15 AM on 9 November 2008
        Arctic sea ice melt - natural or man-made?
        A few details: Rossby radius of deformation (written as if in a spreadsheet formula, sqrt(x) = the square root of x) external: sqrt(g*H) / f where g is the gravitational acceleration, H is the depth of a fluid layer, f is the planetary vorticity and also the coriolis parameter. internal 1.: sqrt(g'*H)/f where g' is g multiplied by the ratio of a density discontinuity to the density (the density of the lower layer). internal 2.: N*H/f N is the buoyancy frequency, H is the vertical extent of the fluid (or of a given phenomena within the fluid**?). The second internal radius of deformation is applicable to a continous stratification, typical of the atmosphere. The Rossby radius of deformation is the horizontal length scale for which the effects of rotation (coriolis effect) and stratification (stability) are similar. The radius of deformation could also be defined as N*H/(f+RV) = N*H/(AV). This has consequences for rotating disturbances such as a hurricane, where the rotation could be thought of as causing some additional coriolis effect with respect to features caught within the rotation. ---- For sloping isentropic surfaces: the geostrophic vertical wind shear projects onto isentropic surfaces as a component of the horizontal wind shear, and thus is part of the isentropic RV. It happens that this component of geostrophic isentropic RV is anticyclonic. If the isentropic surfaces are sloped steeply enough and the horizontal thermal gradient is great enough, it's possible that this anticyclonic contribution could dominate the isobaric RV and the planetary vorticity components of isentropic AV, such that isentropic AV is anticyclonic. In the absence of a horizontal pressure gradient and some nonzero RV, an ageostrophic wind will oscillate with the frequency of an intertial oscillation (= f/(2pi)). **But ageostrophic motions can change the mass and thus pressure distributions. So one can have inertio-gravity waves oscillating at some frequency (following that air) (which can be lower than the inertial oscialltion frequency) which propagate away from an initial disturbance. This relates to geostrophic adjustment - if there is an initial ageostrophic perturbation, there is a process of geostrophic adjustment which radiates mechanical waves. There will generally not be much of a remaining perturbation if the disturbance's horizontal extent was much less than the Rossby radius of deformation; on the other hand, some fraction of the intial perturbation's energy will remain in place as some feature in geostrophic balance for larger scale perturbations. Having a smaller effective radius of deformation in a tropical cyclone due to the cyclone's own rotation can enhance the trapping of pertubation energy. But back to inertial oscillations - what happens if there is some wind field so that a parcel perturbation's oscillating frequency is different. It turns out that the frequency of such an oscillation can be thought of as being in some way proportional to an inertial stability. I think that the frequency is AV/(2pi).** When the AV is anticylonic, there is inertial instability; this is an instability in horizontal motion. Inertial instability is analogous to vertical dry static instability - both are parcel instabilities whose essence can be understood by considering perturbing single air parcels (as opposed to hydrodynamic instabilities that require consideration of some larger-scale macroscopic organization) and both essentially don't occur, at least in larger scale conditions (and away from the surface for static instability) (or away from the lowest latitudes for inertial instability ??). What is more likely to occur or at least be approached, however, is a hybrid of the two instabilities, called symmetric instability. Symmetric instability occurs when the isentropic AV is anticyclonic (or when there is an unstable 'lapse rate' measured along surfaces of constant 'absolute momentum'), so that there is instability to slantwise motions; the stronger restoring force by far is typically that associated with static stability and N, so the overturning that can occur tends to be along isentropic surfaces. Or perhaps more likely, one may find conditional symmetric instability - analogous to conditional instability in the vertical - in which moist convection allows parcel trajectories to be sloped a bit more steeply than the isentropic surfaces. This kind of instability gives rise to some of the banding in precipitation associated with fronts. ---- Back to Rossby waves, the rest will be brief.
130703. Quietman at 04:48 AM on 9 November 2008
        It's the sun
        ps Re: "we don't evaluate the assertions of others using hero-worship or personal preferences" On the former it's not hero worship of Dr. Fairbridge but recognition of character and excellent work, and the latter is a resentment for the underhanded and demeaning treatment that Dr. Spencer receives for his skepticism.
130704. Quietman at 04:32 AM on 9 November 2008
        It's the sun
        You missed my point. So please explain how this natural source of C13 is different from the current source of C13 and how it is affected by catalysts.
130705. Patrick 027 at 17:14 PM on 8 November 2008
        Arctic sea ice melt - natural or man-made?
        I do want to round out the Rossby wave and vorticity subject matter: barotropic PV, isentropic PV, and mass distributions, static stability - the three dimensional fluid. For a geostrophic wind Vg, the coriolis force (or acceleration) is equal and opposite to the pressure gradient force (or acceleration); the coriolis acceleration magnitude is equal to the planetary vorticity f times the wind speed, in the direction to the right of the wind in the northern hemisphere, left in the southern hemisphere (or, since f is negative in the southern hemisphere, it could be described as a negative acceleration to the right of the wind velocity). The geostrophic wind is parallel to isobars on a geopotential or geometric height surface, or to lines of constant geopotential on an isobaric surface (PS note that either way they are the intersections of two sets of surfaces), the speed is proportional to the gradient of geopotential on an isobaric surface (p)or pressure gradient on a geopotential surface (geopotential = z*g, g is gravitational acceleration), and is thus inversely proportional to the spacing of isobars (x,y,z coordinates, spacing on a z surface) or geopotential contours (x,y,p coordinates, spacing on a p surface). It is also inversely proportional to (the absolute magnitude of) planetary vorticity f, since with a smaller f, a greater wind speed is necessary for the coriolis force to balance the pressure gradient force. Geostrophic wind is undefined at the equator (although I think it is possible (?) to define a geostrophic thermal wind - the vertical wind shear due to a horizontal temperature gradient - the key is to take the second spatial derivative of the temperature ...). The geostrophic wind blows cyclonically around low pressure and anticyclonically around high pressure. In x,y,z coordinates, the momentum equations are such that the pressure gradient must be divided by density to get the pressure gradient acceleration. In contrast, in x,y,p coordinates (pressure is p), there is no explicit density-dependence, so that the proportion of geostrophic wind speed to gradient of geopotential is constant for all p values (and there is no solenoidal term). The vector difference between the wind and the geostrophic wind is the ageostrophic wind. The ageostrophic wind can be large compared to the total wind at low latitudes and in smaller-scale features (thunderstorms). Generally, though, the geostrophic wind is close to the total wind for larger-scale motions at middle and high latitudes at sufficient height above the surface - with relatively bigger ageostrophic winds in frontal zones and around intense cyclones (due at least in part to centrifugal acceleration). Because the geostrophic wind is balanced with the pressure gradient, wind that is geostrophic won't accelerate (except for friction/mixing). Following the air as it moves (or even if it happens to stand still for a moment) the pressure gradient can/will change, causing an imbalance - an ageostrophic component, which allows and causes acceleration. Thus even if small, the ageostrophic wind is important. Generally, the ageostrophic wind (on large scales) makes up a 'secondary circulation' (which can involve horizontal divergence and vertical motion) which adjusts both the motion and the mass distribution (horizontal convergence, and vertical motion in pressure coordinates (or any change in pressure following the motion for any coordinate system) causes adiabatic temperature changes, and together this affects the mass distribution), tending to keep the wind and the pressure variation close to geostrophic balance, or else a gradient wind balance, where the centrifugal acceleration and coriolis acceleration due to the wind together balance the the pressure gradient acceleration (the centrifugal acceleration depends on the speed and the curvature of trajectories; trajectories can curve in the opposite direction of streamlines but a trajectory which 'stays with' a relative maximum or minimum in pressure will tend to curve the same way as streamlines (refer to last paragrarph of comment 302). This all assumes hydrostatic balance (gravity balances the vertical pressure gradient force), which is a very good approximation for at least the larger-scale motions. I'm not even sure that the atmosphere would deviate significantly from hydrostatic balance in high-frequency gravity waves (unless they have large amplitudes ?). But such deviation does play a role in the stronger thunderstorms. Hydrostatic imbalances account for vertical acceleration (which are very small for larger-scale motions). When the ageostrophic wind can have any value, there isn't a clear correspondence between vorticity and the mass distribution. But there is a relationship between geostrophic vorticity and the mass distribution (at least with the hydrostatic approximation). That relationship (for the following consider just a geostrophic wind and the geostrophic RV that comes with it): barotropic PV: relative vorticity (RV for this discussion) is cyclonic about low pressure, anticyclonic about high pressure (for pressure at a given z or geopotential). When the surface is flat (constant geopotential), the relative vorticity is correlated with the surface pressure in so far as local minimums or maximums are concerned, so that barotropic PV (proportional to AV/surface pressure) has a postive correlation to AV and anomalies of such PV have such correlations to RV. The relationship may be less clear-cut at some distance from any pressure maximum or minimum - although if one decomposes the pressure field into a basic state and some anomalies, one might again find some more clear relationship with the component of RV associated with the anomalies (provided the curvature **(the laplacian, which as an operator is the dot product of the gradient operatore with itself, equal to the sum of second derivatives in x,y,z, although in this context, just x and y)**, of the anomaly pressure field is positive where the pressure field anomaly is negative. This has to be true on the largest scale for continuity, but smaller wiggles or regions of constant gradients can go against this). When the surface has topography - variations in z, then the surface pressure is not entirely correlated to horizontal pressure variations; however the constancy of topography (on the relevant time scales) allows this topographic effect on barotropic PV to be considered analogous to the effect of planetary vorticity; a high plateau is analogous to higher latitudes. (A constant basic state surface pressure variation even in flat terrain could also be considered analogous to planetary vorticity variation - for example, the pressure variation due to the equilibrium paraboloid shape of the surface of water in a spinning dish.) Baroclinic fluid: isentropic PV (IPV) - The correlation between IPV variation and AV or RV variation is even less clear in general (to me, anyway - which is partly why I've been a little slow to pick up 'IPV thinking'). Barotropic PV is invariant in the vertical. IPV is not (generally). IPV is proportional to AV * [- d(potential temperature)/dp] - the negative of the vertical gradient of potential temperature in x,y,p coordinates (in stable air, d(potential temperature)/dp is itself negative, so using the negative of this allows a positive AV in stable air to have a postive PV). What would make for a clear-cut relationship is for a relative maximum in AV to correspond to a relative maximum in stability. Well, consider a relative maximum in cyclonic RV over vertical distance (which will correspond to a cyclonic AV anomaly since planetary vorticity doesn't have 'anomalies'). This means that below, cyclonic RV increases with height, and above, it decreases. If RV is geostrophic or nearly so, then that has implications for pressure variations. The greatest curvature (laplacian, d2/dx2 + d2/dy2) of the pressure field (along a horizontal plane) (or the greatest curvature of the geopotential field on an isobaric surface) must occur at the level of greatest cyclonic RV, decreasing away going down and up. The hydrostatic balance requires that the curvature of the temperature field (along either a z or a p surface, depending on chosen coordinate system) be positive below and negative above - that the thermal gradient (which points to warmer air) is divergent below and convergent above; if this is centered on relative maxima and minima, there would be (in the horizontal) relatively colder air surrounded by relatively warmer air below the cyclonic RV maximum, and warmer air surrounded by relatively colder air above the RV maximum. This implies that, if horizontally centered on temperature maxima/minima, the RV maximum is centered in the horizontal and in the vertical on a maximum in static stability. There will thus be, except for the planetary vorticity gradient, a relative maximum of IPV centered both in the vertical and horizontal on the RV maximum (provided planetary vorticity is cyclonic - which is always true). And if this is not actually centered on temperature maxima/minima? Well, the curvature (on either a z or p surface) of the stability must still be a maximum at the vertical level of the RV maximum and the RV maximum must be centered in the horizontal on the curvature of the stability (the convergence of the gradient of stability in x,y). The IPV maximum could be skewed to the side of RV if there is some component of the stability distribution that has a non-divergent gradient - the IPV maximum would be in between the highest RV value and the higher stability values. Also, it should be kept in mind that a relative cyclonic RV maximum doesn't necessarly occur with actual cyclonic RV - for example, if there is a strong enough anticyclonic RV above and below, the relative maximum in cyclonic RV could be a relative minimum in anticyclonic RV. It could still be a relative maximum in cyclonic IPV, though. As with barotropic PV, the correlation of IPV variations to RV variations could be made more clear by subtracting a basic state and then considering remaining anomalies (which themselves might be broken into components). PS as with barotropic RV in two dimensions, there is invertability with IPV; given sufficient boundary conditions (and a specification of the wind being geostrophic or in gradient wind balance), the wind field (or the specified component of it) and thus also the pressure field, can be determined, and the later also determines (again, with sufficient boundary conditions) the (potential) temperature field. (PS in the atmosphere, varyations in composition have relatively minor effects - when the specific humidity is quite high, then to be more accurate, a 'virtual temperature' can be found - this is the temperature that dry air would have to have to have the same density. In the ocean, salinity is of great importance, and so rather than considering potential temperature, one may consider potential density - the density the water would have if brought adiabatically (and without mixing or phase changes, though 'adiabatically' generally includes these constraints) to some reference pressure (such as at the surface).) There is also the consideration that IPV is evaluated based on the RV evaluated from the winds on an isentropic surface. Isentropic surfaces can slope considerably more than pressure surfaces, so some of the isentropic RV in (x,y,theta) coordinates (the greek letter theta is used to denote potential temperature) can come from vertical wind shear in either (x,y,p) or (x,y,z) coordinates. Also, purely non-divergent horizontal winds which vary with height, with no vertical motion in (x,y,p or z) coordinates, can, if a component of the wind shear is parallel to the horizontal temperature gradient (notice such a component must be ageostrophic), result in horizontal divergence or convergence and the accompanying vertical stretching in (x,y,theta) coordinates - note that adiabatic motion automatically has zero vertical 'motion' in (x,y,theta) because theta is constant following the motion; the vertical stretching is the increased seperation of isentropic surfaces in the z or p dimension. This happens because, even while the horizontal temperature gradient and thus x,y spacing of isentropes is invariant in this scenario, the isentropic surfaces are being tilted - if warm air advection decreases with height or cold air advection increases with height, then the isentropic surfaces are being taken from the horizontal and tilted toward the vertical. In the process, the projection of such a surface onto a vertical plane perpendicular to the thermal gradient is not changing in area if each such surface extends from top to bottom of whatever domain is considered (and the horizontal spacing of isentropes does not change), and so the horizontal component of isentropic RV does not change (however, if there is horizontal variation in the wind, the same may not be true of the actual vertical wind shear - since in this scenario the horizontal thermal gradient remains constant, the geostrophic wind shear remains constant, thus horizontal advection of the wind can produce an additional ageostrophic wind), but the horizontal projection of each isentropic surface (spanning a given vertical distance) is decreasing toward zero, and so (the vertical component of) isentropic RV increases toward infinity which conserving (the vertical component of) IPV as the vertical spacing (p or z) of isentropes increases to infinity (the stability goes toward zero); the volume between any two isentropic surfaces within a given vertical distance (p or z) is conserved (PS this is all assuming adiabatic and inviscid processes)...*****(may continue on that topic later) (PS note that the isentropes are not sloped in (x,y,p) where there is a relative temperature maximum or minimum in the horizontal). So the relationship between PV and RV can be complicated, but in general, a PV anomaly can be associated (co-located) with an RV anomaly of the same sign or vice versa. An IPV anomaly at a given vertical level will be accompanied by an RV anomaly field that extends both higher and lower than the IPV anomaly (the extent is reduced when static stability overall is higher** and also when the horizontal scale of the IPV anomaly (it's wavelength, for example) is smaller), and again the wind field generally extends farther horizontally than the RV anomaly itself. Thus if an IPV anomaly is confined either horizontally or vertically, it can, via the Rossby-wave propagation mechanism, propagate or initiate disturbances that propagate not only horizontally but vertically.
130706. at 16:07 PM on 8 November 2008
        Climate's changed before
        Conspicously absent from consideration of what could have caused the warming for the 30 year period is ENSO and PDO. Here is a 58 year ENSO chart. http://www.cdc.noaa.gov/people/klaus.wolter/MEI/ts.gif Notice that prior to 1977 La Nina dominates the chart. After 1977 El Nino dominates the chart. The dominance of El Nino corresponds with the temperature rise of the last 30 years. Climate scientist Dr. Roy Spencer has calculated that up to 70% of the temperature rise that we have seen could be accounted for by ENSO and PDO patterns. There also seems to have been a flip in the PDO cycle in the last year or so that could well indicate another 20 years of flat or negative temperature trends. By the way, you may notice that the El Nino dominance in the chart was greatest from about 1977 to 1998. After that the distribution is a little more even. This corresponds well to the flatening of the temperature trend for the last decade. While that point is also challenged in this blog, I have proven it to be true in the relevant section.
        Response: ENSO has been considered as a possible driver of global warming. The El Nino Southern Oscillation does show close correlation to global temperatures over the short term. However, it is unable to explain the long term warming trend over the past few decades.
130707. Philippe Chantreau at 15:37 PM on 8 November 2008
        What does CO2 lagging temperature mean?
        Actually,Mizimi, my readings suggest that low biodiversity is very likely to be associated with paucity of life, especially if the conditions undergo further change. Any state of low diversity is probably transient, manifesting a transition to a new equilibrium. It is not desirable for any life form to take over and overwhelm all other life forms. In fact, it does not seem that low diversity is something that commonly happens in the natural world. What should be especially concerning is decreasing biodiversity in a biome where there used to be a lot of diversity.
130708. saluki at 15:34 PM on 8 November 2008
        It hasn't warmed since 1998
        This one certainly is true now. There has been no warming for the past 11 years. Here is the chart for RSS, UAH, HadCrut3 and GISS. http://reallyrealclimate.blogspot.com/2008/10/updated-11-year-global-temp-anomoly.html Double click the chart to enlarge it. Also, when we correct for ENSO, the temperature trend remains virtually flat. Here is a chart comparing raw HadCrut3 with ENSO corrected HadCrut3. http://reallyrealclimate.blogspot.com/2008/07/gavin-schmidt-enso-adjustment-for.html As you can see, there is virtually no difference. The period in question had 7 ENSO event. 4 were El Ninos and 3 were La Ninas. Taken together they had almost no effect on the trend line.
130709. Patrick 027 at 14:43 PM on 8 November 2008
        Arctic sea ice melt - natural or man-made?
        "Arctic Sea Ice Is Suddenly Getting Thinner As Well As Receding" ... important example of the overall concept of thermal inertia / heat capacity and latent heat, or even more generally, any other aspect of climate inertia (sea water composition, vegetative feedbacks, etc.). "Less Ice In Arctic Ocean 6000-7000 Years Ago" The extent of the difference is news to me, but I think at least the Northern Hemisphere was warmer back then compared to more recent times (though maybe not anymore for the last decade or so? - we're getting into that territory). At least some of this longer-term change is caused by orbital (Milankovitch) forcing.
130710. Philippe Chantreau at 12:23 PM on 8 November 2008
        A Great Science Fiction Writer Passes - Goodbye Dr. Crichton
        I'll put "Rising Sun" on my list, John, thx for the tip.
130711. chris at 09:57 AM on 8 November 2008
        Water vapor is the most powerful greenhouse gas
        Not really Mizimi. Remember (see post #14/#20) that all we're doing is adding a small amount to the lower atmosphere which is a tiny proportion of that produced in the natural evaporation/precipitation cycle. We can blast and spray water into the atmosphere to our hearts content - it just comes out again. The warming effect of water vapour results from the column that exists through the entire atmosphere whose concentration responds dynamically to the atmospheric temperature and pressure. That's the greenhouse contribution: the amount of water vapour that is retained at equilibrium in relation to the atmospheric tempeature and pressure. By pumping a tiny excess amount of water vapour into the lower atmosphere, all we're doing is supplementing the already saturated amount that is there from the natural evaporation/precipitation cycle. I suppose that if one were able to measure this, there should be 0.05% more rainfall as a result! Water vapour isn't 10x more effective a GC than CO2. Despite the fact that the water vapour concentration of the atmosphere is 5 times that of CO2 (around 0.3% by mass for water vapour cf around 0.06% by mass for CO2), the contribution of CO2 to the greenhouse effect is at least 10% (and more like 25-30% with the water vapour feedback). Basically, over a period of a week or two a very tiny supplement of the natural evaporative water vapour cycle is added to the atmosphere from where it falls right out again. So if there is any additional contribution to the lower atmospheric water vapour this is a tiny steady state value that cannot increase.
130712. chris at 06:35 AM on 8 November 2008
        It's the sun
        No, that's not correct Quietman. Again you're using a paper to address an issue that is not, in fact, what the paper is about at all. The measure of 13C/12C ratios in CO2 in our environment is straightforward and shows a decrease as expected from the return of vast amounts of 13C-depeleted carbon into the atmosphere from long-sequestered fossil fuels originally derived from plant sources. That indicates very clearly that the massive enhancement of atmospheric CO2 (and that being forced into the oceans as a result) is from oxidation of fossil fuel (and a bit from deforestation) and doesn't significantly derive from tectonic activity. Which we know anyway, since we know how much CO2 we've produced during the industrial age, and can measure the increasing amounts in the ocean due to forced partitioning from the atmosphere. And of course we know from the high resolution 2000 year CO2 record and the lower resolution records spanning millions of years, that tectonic activity (volcanic or undersea sources)has made a trivial contribution to the net CO2 concentration. The paper that you cited [P.K. Swart (2008) Proc. Natl. Acad. Sci. USA 105, 13741-13745] is about something quite different. It addresses the mismatch between the apparently synchronous variations in 13C content of carbonate sediments deposited off the margins of low latitude shallow marine platforms and the pattern in the open oceans, and concludes that this difference can be resolved by noticing that the apparent synchrony relates to sea level changes and synchronous flooding of the platforms. So it's a paper that may have resolved an incompatibility between some marginal and deep ocean data sets. It doesn't have anything to do with the partitioning of carbon isotopes in fossil fuels and the readily measured variation in 13C/12C ratios that occur when 13C-depeleted carbon is returned to the biosphere by oxidation of fossil fuels. One should make an effort to find out what a paper is about before citing it in support of something on which it might have no bearing. Remember that science is all about the evidence, and the evidence should be appropriate to the issue at hand!
130713. chris at 05:52 AM on 8 November 2008
        A Great Science Fiction Writer Passes - Goodbye Dr. Crichton
        John, I wasn't really meaning the political situation as such (e.g. Reps/Dems!), but was referring more to the period in which widespread misrepresentation of the science by propagandising from many quarters had such a dismal (and anti-democratic) effect on public understanding of this issue. Sadly Michael Crichton got caught up in all of that. I think we're well over the worst of it and it's increasingly difficult for "skeptics" (!) to misrepresent the science with any conviction nowadays. But it seems appropriate to consider Michael Crichton's role as a misrepresenter of the science on global warming in the context of this web site, which has a theme of addressing "skeptical" misrepresentation. I wonder whether Michael Crichton would consider that he made a worthy contribution to the public's understanding of climate science and especially to the relationship between science and policy. It would be interesting to know why he chose the role he chose. In the end Crichton's role in this will probably be forgotten, and it's the films that he will be remembered for...a more worthy memorial.
130714. Mizimi at 05:38 AM on 8 November 2008
        Evaporating the water vapor argument
        Chris, you seem to have missed my point which is there is a limit to incoming heat and therefore a limit to the amount of energy that can be 'retained' by GG effects. So there is an upper temperature limit ( which we may not find to our liking) No? And yes, maybe I am playing with semantics but I don't see GG's 'adding' anything....only moderating the rate at which heat is lost.
130715. Quietman at 05:28 AM on 8 November 2008
        It's the sun
        chris I only recently posted a link to an article on how the whole 13C evidence needs a rethink. I think that I was addressing Mizimi in the Arctic Ocean thread when I posted it. Not sure now. We only thought we knew what we know on that one.
130716. chris at 05:05 AM on 8 November 2008
        Models are unreliable
        O.K. Dan, I think we're making some progress. It seems your "disagreement" with the science relates to a misunderstanding of the nature of "feedback" in relation to the earth's energy budget combined with a reliance on inappropriate analogies ("anti-missile missiles"; "cruise control devices"), a misunderstanding of insolation effects resulting from the cyclical elements of the earth's orbital properties that modulates the pattern of insolation on the 10's of 1000's of years timescale, and (judging by your previous posts and your dismal web page) a desire to impose a false view of this entire subject through a propagation of contrived misrepresentation. Is that "hostile"? Possibly...but I'd prefer "trenchant", since I think one should address contrived misrepresentation with a bit of vigour! Feedbacks. The evidence indicates that there is a NET positive feedback to enhanced atmospheric CO2 concentrations. You’ve said in another post somewhere that positive feedbacks occur with carbon dioxide and water. That’s exactly right. The warming effect of enhanced atmospheric CO2, for example, is amplified by a water vapour feedback, and certainly an albedo feedback. It seems that we agree about that. Overall the evidence indicates that the NET feedback results in a warming resulting from doubling of atmospheric CO2 of around 3 oC (+/- a bit). You seem to have a residual problem with this…I wonder whether it relates to your reliance on analogies and a textbook (Phelan, 1967) based on the analysis of control systems. Unfortunately feedbacks in relation to “control systems” are not really appropriate (see following): Dynamic systems/control systems. The climate is a dynamic system with elements involving forcings and feedbacks that "act" on many different timescales, as well as stochastic and non-stochastic elements that provide “noise” in various accessible parameters (such as the surface temperature anomaly). It differs from your notion of a “control system” in that the feedbacks are neither “designed” nor constrained to maintain an equilibrium, even if parameters (like the earth’s surface temperature anomaly) might well be in equilibrium for long periods as a result of a relatively steady state in relation to forcings (e.g. the sum of solar and greenhouse contributions). If there is a change in these forcings (a change in solar output or a change in greenhouse gas concentrations) the earth doesn’t respond so as to maintain an equilibrium surface temperature. The earth’s climate system evolves dynamically under the influence of the new forcings until a new (dynamic) equilibrium is reached. In the case of enhanced greenhouse forcing at constant insolation, the new equilibrium is around 3 oC of raised surface temperature per doubling of atmospheric [CO2]. There’s a NET positive feedback. Does the climate system have elements of your “control systems”. It does a bit. For example the vast oceans provides a heat reservoir that regulates surface temperature somewhat, both directly and through the evaporation/precipitation cycles. The vast ice sheets also provide a bit of a thermal “buffer” due to the large heat capacity associated with the ice/water phase transition. Over very long periods greenhouse-induced warming is countered by increased weathering that draws CO2 out of the atmosphere. But overall the earth isn’t really under the influence of “control systems” and certainly doesn’t respond in that manner. It responds to a change in forcings via dynamic transitions to new (dynamic) thermal equilibria. Milankovitch/feedbacks. I suspect you’re still confused by these. Variations in the earth’s orbital climatic precession, obliquity and eccentricity result in a rather complex, but well-defined variation in insolation that matches rather well the progression of temperature anomalies in the ice cores. I suggest that you look at some of the papers linked by John Cook here: http://www.skepticalscience.com/co2-lags-temperature.htm especially Petit et al, 1999 and Shackleton, 2000. If you have access to last week’s Nature magazine (6th November) read the paper on page 85 (Lisiecki et al (2008) “Atlantic overturning responses to Late Pleistocene climate forcings” Nature 456, 85-88.), or the accompanying commentary by Michael Crucifix “Climate’s astronomical sensors” on page 47. I know that you don’t like reading scientific papers and prefer weird websites and non-science magazines. However, one may as well obtain one’s information from the source that mature and well-informed policymakers source theirs! The significant NET positive feedback that amplifies CO2-induced warming relates to a relatively constant insolation. So in our present situation with a rather constant solar output and no significant Milankovitch contributions for many thousands of years to come, the enhanced greenhouse forcing is giving us (and will give us further) warming resulting from the earth’s climate sensitivity to enhanced [CO2] which the best evidence indicates is near 3 oC (+/- a bit) of warming for a doubled [CO2]. Obviously if the solar contribution diminishes either in relation to total solar output, or due to altered insolation patterns during Milankovitch cycles, the earth will still undergo cooling even ‘though there there is (a) a NET positive climate warming feedback to enhanced [CO2] under conditions of constant insolation, and (b) a residual highish concentration of atmospheric CO2 (since CO2 is drawn only very slowly out of the atmosphere).
130717. Mizimi at 04:58 AM on 8 November 2008
        It's Urban Heat Island effect
        The satellite photo shows cities at one point in time. The global anomoly picture is an average of a years data. If I stood in Times Square and you took a photo of me, I would clearly stand out. If you left the camera running and took 365 photos on ONE frame I would disappear...other things would get between me and the camera and obscure my image. This is what the GA picture does to UHI effects.
130718. John Cross at 04:34 AM on 8 November 2008
        A Great Science Fiction Writer Passes - Goodbye Dr. Crichton
        Chris: That was part of a nasty little period in US history, the worst of which has happily passed; I suspect (and hope) that you are correct. It will be interesting to see what the US does about climate change under Obama. I suspect that the current economic problems will lead to an automatic GHG reduction - but not in a way desirable. However I suspect that our good host would call that off topic and I would not want to see this thread devolve into a political thread. Philippe: Good authors all. I will also note that T.J. Bass is a medical doctor like Michael Crichton. One of the things that I found impressive about Crichton is that he was able to use technology in works that you wouldn't normally think of as science fiction. For example Disclosure (which I did not really like) and Rising Sun (which I did). Regards, John
130719. Philippe Chantreau at 03:44 AM on 8 November 2008
        A Great Science Fiction Writer Passes - Goodbye Dr. Crichton
        Fair enough. I'm not so much a fan of Crichton when it comes to Science Fiction writing. I think that Asimov, Heinlein, Ted Sturgeon, John Brunner, Van Vogt, Philipp K Dick, and others have works that are more interesting. Like Norman Spinrad short stories too. My all time SF favorite remains T.J. Bass' "Godwhale," which I warmly recommend to anyone who is into the genre. Crichton's Jurassic Park pieces were a lot of fun to watch on film.
130720. Mizimi at 03:30 AM on 8 November 2008
        Water vapor is the most powerful greenhouse gas
        But whilst that WV is in the atmosphere it is acting as a GG and thus delaying heat emission by the earth. The actual amount of 'natural' WV is increased by the addition of WV from man's activities and so the overall warming effect must be enhanced...after all is that not the argument for CO2? And WV is 10x more effective a GG than CO2. Unless one accepts there is a 'saturation' limit beyond which no further GG additions has an effect. Also if you add in the other sources of manmade WV (allowing 600B tonnes for agriculture)) we put more than 1000 billion tonnes a year into the atmosphere, which is 1 x 10^15 kg....0.2% My overall point here is that the amount of AWV has been increasing post 1950 ( the actual amounts I have yet to research) and the effect of that increase has to be included in any modelling.
130721. chris at 01:50 AM on 8 November 2008
        A Great Science Fiction Writer Passes - Goodbye Dr. Crichton
        Yes that's a pretty fair appraisal. Michael Crichton should be remembered for his excellent early science fiction and the outstanding films that flowed naturally from several of his best books. The ideas and solid writing completely lended themselves to top quality and thought-provoking films. The Andromeda Strain was an awesome film (I hadn't realised that it was a Michael Crichton based-piece). So kudos to Crichton. And not only would I echo your sentiment that he should be remembered for this body of work, I'm pretty sure that he will be. I also agree that we shouldn't forget the travesty of his "State of Fear", and more specifically the political mileage that was made of that dreary and scientifically-illiterate polemic, and the manner in which dismal vested interests elevated Crichton the novelist to the status of some sort of an "expert" on climate-related matters! In my opinion the manner in which Crichton's fantasy was puffed up to assume the guise of reality, ultimately did Crichton a disservice. That was part of a nasty little period in US history, the worst of which has happily passed; Michael Crichton's legacy will be the books and especially the films that resulted, and quite right too!
130722. chris at 20:03 PM on 7 November 2008
        It's the sun
        Re #195 Yes, we do know that an insignificant amount of this massive amount of CO2 that is being pumped into the atmosphere and absorbed by the oceans comes from volcanic/tectonic activity. We do know that the vast bulk of this is from burning fossil fuels (with a bit from forest burning). Remember that fossil fuels are highly depleted in 13C, since the plants from which the fossil fuels are derived select the 12C isotope for incorporation into their (initially) generic carbohydrate [(CHOH)6]. On the other hand oceanic subducted carbonates released by tectonic activity is indifferent to the isotopic composition of the carbon in the CO2 from which it is "fixed". So as fossil fuels are burned, they release their 13C-depleted carbon back into the atmosphere, and the 13C content of the CO2 in our environment drops. This is easy to measure in the real world (the 13C/12C ratio) using a mass spectrometer. The 13C content of CO2 in our environment is dropping just as expected from a fossil fuel source of CO2, as the atmospheric CO2 content rises dramatically in response to our massive rate of oxidation of long-sequestered fossil fuels There's lots of information on this of course! See, for example: Francey RJ, Allison CE, Etheridge DM, et al. (1999) A 1000-year high precision record of delta C-13 in atmospheric CO2 TELLUS B-Chem Phys. Meteor 51, 170-193 and D. M. Etheridge et al (1996) "Natural and anthropogenic changes in atmospheric CO2 over the last 1000 years from air in Antarctic ice and firn J. Geophys Res. 101, 4115 -4128 and so on...
130723. chris at 19:45 PM on 7 November 2008
        Water vapor is the most powerful greenhouse gas
        O.K., 25 billion tons of water vapour released in cooling towers and a bit more from other activities. Thta makes more sense. Let's use your 25 billion tons number and see whether this is significant in any way with respect to greenhouse gas warming. The answer is no...not really. This relates to the fact that water vapour in the atmosphere comes to a fairly fast equilibrium with respect to the atmospheric temperature and pressure (see my post #14). A good handle on this can be gleaned from a comparison of the water vapour released from cooling towers (and from fossil fuel burning overall) in relation to the overall amount of water vapour produced in the natural evironment by evaporation and precipitation. So we can use your numbers and compare the 25 billion tons of water vapour you indicate is released per year: 25 x 10^9 tons = 2.5 x 10^13 kilograms of water to the total amount of evaporation/rainfall worldwide per year: 5 x 10^17 kilograms of water. In other words the excess water vapour released into the atmosphere by the cooling tower/fossil fuel burning is around 0.005% of that released and precipitated yearly during the natural evaporative water cycle each year. in other worlds insignificant.
130724. Quietman at 15:43 PM on 7 November 2008
        Volcanoes emit more CO2 than humans
        2004 Indian Ocean Tsunami Biggest in 600 Years turns out to be more evidence of tectonic upset.
130725. Quietman at 15:39 PM on 7 November 2008
        Arctic sea ice melt - natural or man-made?
        Earth's Climate - Past and Future - William F. Ruddiman This sounds like what I am looking for. I don't want to study for exams, just do some light reading on subjects of interest. Thanks ps You might find this interesting: ScienceDaily (Nov. 3, 2008): Arctic Sea Ice Is Suddenly Getting Thinner As Well As Receding "The research - reported in Geophysical Research Letters - showed that last winter the average thickness of sea ice over the whole Arctic fell by 26cm (10 per cent) compared with the average thickness of the previous five winters, but sea ice in the western Arctic lost around 49cm of thickness. This region of the Arctic saw the North-West passage become ice free and open to shipping for the first time in 30 years during the summer of 2007." and also from ScienceDaily (Oct. 20, 2008) Less Ice In Arctic Ocean 6000-7000 Years Ago Both interesting.
130726. Patrick 027 at 15:37 PM on 7 November 2008
        Arctic sea ice melt - natural or man-made?
        There was a book called "Supercontinent" I saw a few months ago in the library; I think that had a little paleoclimate in it (PS I couldn't claim to have actually read through all or most of these books; some I've gone through for specific chapters/sections/topics...). "Cambridge Encyclopedia of Earth Sciences" (which, depending on library, may be checked out despite it's name) is another good one, though a bit 'old' (1980?), but covers a LOT (and it's BIG - I think somewhere around 1000 pages). If you're at the library, I'd suggest also Encyclopedia Britanica - I think they had articles such as "Climate and Weather", "Atmosphere", "Earth"; I forget which article it was in but a great section on the magnetosphere, too. If your library has McGraw-Hill Encyclopedia of Science and Technology, that's a good one too... well now I'm probably just giving you stuff you could easily have found by yourself. With many of the books I mentioned being textbooks, of course your best bet would be a college library. I should mention, I only remember or know of Rossby waves being discussed in the first four that I mentioned (Holton, Cushman-Roisin, Bluestein, Martin) and I think the first three of those have the most coverage of the subject.
130727. Quietman at 15:30 PM on 7 November 2008
        It's the sun
        Mizimi They might make it in blue, I know they make it in colorless, green and amber. I guess that the colorless translucent is the way to go then. PVC isn't strong enough, the snow and ice would break it before I could clear it off, in this area fibreglass is used for strength. I appreciate the suggestions, thanks. PS Just finished reading this one: Sunlight Has More Powerful Influence On Ocean Circulation And Climate Than North American Ice Sheets from ScienceDaily (Nov. 6, 2008).
130728. Mizimi at 09:32 AM on 7 November 2008
        Water vapor is the most powerful greenhouse gas
        PPS; the figures don't include WV from combustion ( all sources of), commercial airconditioning systems, fogging systems, domestic irrigation, or simple respiration ( human component expected to increase by 50% by 2050)
130729. Mizimi at 09:27 AM on 7 November 2008
        What does CO2 lagging temperature mean?
        Low biodiversity is not the same as a paucity of life. Some lifeforms will flourish under conditions which cause others to perish. As an aside....we have the ability to conduct experiments at CO2 and temp levels intimated by the paleoproxy records....I wonder if anybody is??
130730. Mizimi at 09:12 AM on 7 November 2008
        It's the sun
        QM: Green plastic is not a good colour! better is simple translucent or the slightly 'bluish' UV stabilised pvc.
130731. Mizimi at 09:02 AM on 7 November 2008
        Water vapor is the most powerful greenhouse gas
        PS: I cannot find figures for agricultural irrigation and windage losses: some of that evapotranspiration would be offset by 'natural' plant growth, but to what extent is not clear, so that 1870 billion tonnes is probably a bit high.
130732. Mizimi at 08:58 AM on 7 November 2008
        Water vapor is the most powerful greenhouse gas
        Yup, got my powers mixed up! That should have been 25 billion tons. There are a large number of water usage sites which give estimates for various activities: Evaporation from reservoirs: 275cubic km/yr (275 billion tonnes) World industry: 90 cubic km/yr.....90 billion tonnes (which includes the world's 63,590 power stations) Agriculture 1870 cubic km/yr ( listed as evapotranspiration as they can't tell the difference) So a reasonable estimate for AWV added to the atmosphere is 2200 billion tonnes a year which otherwise would not be there. Which is a lot more than the CO2 added.
130733. Quietman at 07:15 AM on 7 November 2008
        It's the sun
        Re: "we look at the EVIDENCE that they might use to support their statements." I don't think so.
130734. Quietman at 07:12 AM on 7 November 2008
        It's the sun
        chris Nice dissertation on how CO2 can be absorved by the ocean. Now show how much is tectonic. The fact is that you can't. This is an area that is not well understood. This is indeed claiming to know what we actually know very little about. 1) CO2 relaesed from undersea volcanos and ridges is direct to the oceans. 2) Fertilzer entering the oceans causes algal and bacterial blooms which then die, rot and produce methane and add carbon direct to the oceans, at the same time reducing O2 production. There are knowns but the actual amounts are total unknowns. Go ahead, please tell me that mankind knows everything that happens under the oceans. Then go tell the scientists that are still trying to figure it out, I am sure they would greatly appreciate it. You just don't get it. As much as we may know there are many times as much things that we do not know and pretending to know will not help.
130735. chris at 05:12 AM on 7 November 2008
        It's the sun
        Re #192 I'm don't understand the rest of your post. What articles are you referring to? As for your non-sciency assertions about Rhodes Fairbridge and "Spencer" (Spencer Tracy?!), I can't glean what you're referring to in the context of my post or this thread. Whatever you are referring to, we don't evaluate the assertions of others using hero-worship or personal preferences. Instead (if we are interested in the science), we look at the EVIDENCE that they might use to support their statements.. Your assertions about peer review and "fear" are not very intersting, since they're just conspiracy theory bluster and without any foundation whatsoever! Let's try to scientific and skeptical!
130736. chris at 05:01 AM on 7 November 2008
        It's the sun
        Re #192 That's quite incorrect Quietman. We know very well that our emissions are forcing up the oceanic CO2 concentration by prodigious amounts. We can measure this in a number of ways. We know quite well the scale of our emissions and can determine that around 40-50% of these have remained in the atmosphere. Much of the rest has gone into the oceans. We know that this has to occur from simple understanding of physical equilibria (Le Chatelier's principle). And we can measure this directly through analysis of inorganic carbon in the oceans, or via the reduction in ocean pH [see abstracts of Sabine et al (2004) and Feely et al (2004) below, for example]. There are many measures that demonstrate without question that we are pumping CO2 into the atmosphere in massive amounts and that this is disturbing the CO2 equilibrium between the atmosphere and the oceans well towards oceanic CO2 dissolution and dissociation into bicarbonate, and H+: CO2(air) <->CO2(aq)<-> H2CO <->HCO3- + H+ <-> CO3-- + H+ That's very well understood and characterised in the real world. We really shouldn't pretend not to know what we do know very well! Sabine CL et al (2004) The oceanic sink for anthropogenic CO2 Science 305, 367-371. Abstract: "Using inorganic carbon measurements from an international survey effort in the 1990s and a tracer-based separation technique, we estimate a global oceanic anthropogenic carbon dioxide (CO2) sink for the period from 1800 to 1994 of 118 +/- 19 petagrams of carbon. The oceanic sink accounts for similar to 48% of the total fossil-fuel and cement-manufacturing emissions, implying that the terrestrial biosphere was a net source of CO2 to the atmosphere of about 39 +/- 28 petagrams of carbon for this period. The current fraction of total anthropogenic CO2 emissions stored in the ocean appears to be about one-third of the long-term potential." R.A. Feely et al (2004) Impact of Anthropogenic CO2 on the CaCO3 System in the Oceans Science 305, 362-366. Abstract: "Rising atmospheric carbon dioxide (CO2) concentrations over the past two centuries have led to greater CO2 uptake by the oceans. This acidification process has changed the saturation state ofthe oceans with respect to calcium carbonate (CaCO3) particles. Here we estimate the in situ CaCO3 dissolution rates for the global oceans from total alkalinity and chlorofluorocarbon data, and we also discuss the future impacts of anthropogenic CO2 on CaCO3 shell–forming species. CaCO3 dissolution rates, ranging from 0.003 to 1.2 micromoles per kilogram per year, are observed beginning near the aragonite saturation horizon. The total water column CaCO3 dissolution rate for the global oceans is approximately 0.5 ± 0.2 petagrams of CaCO3-C per year, which is approximately 45 to 65% of the export production of CaCO3."
130737. chris at 04:34 AM on 7 November 2008
        Water vapor is the most powerful greenhouse gas
        I wonder if your numbers are incorrect Mizimi. The total yearly worldwide emissions of CO2 are something a bit under 30,000 million tons [***]. I suspect your 25,000 billion tons of water vapour evaporated in cooling towers should similarly be 25,000 MILLION tons and not 25,000 billion tons. Where did your numbers come from? [***] see table 3 at: http://www.eia.doe.gov/oiaf/1605/ggrpt/
130738. Patrick 027 at 12:03 PM on 6 November 2008
        Arctic sea ice melt - natural or man-made?
        If you need anything clarified, please ask. (There's a lot I don't know but I'll try.) Books: I'm quite surpised that Cushman-Roisin is so expensive. You may want to look into Holton (An Introduction to Dynamic Meteorology). Two other books (these focus on the midlatitude weather): Mid-Latitude Atmospheric Dynamics A First Course - Jonathan E. Martin and Synoptic-Dynamic Meteorology in Midlatitudes Volume II Observations and Theory of Weather Systems - Howard B. Bluestein The second starts off without introduction to atmospheric physics; I think you could start with Volume I but I don't think you'd need it if you have either Holton, Martin, or maybe Cushman-Roisin. Bluestein, Martin, Holton, and Cushman-Roisin are all focussed on dynamics; of those, Cushman-Roisin gives the most attention to oceanic dynamics as well as atmospheric dynamics. There is also: Atmospheric Science An Introductory Survey - John M. Wallace, Peter V. Hobbs This is a very general book, which even discusses atmospheric electricity and the magnetosphere, as well as radiation, cloud microphysics, and the general circulation. Just the last two chapters (in the edition I have, anyway) go into mathematical detail regarding momentum and dynamics. Global Physical Climatology - Dennis L. Hartmann As with Wallace and Hobbs, a variety of subjects are covered; the distinction is a focus on climatological aspects here. Includes a chapter on oceanic circulation. Also discusses paleoclimatology, natural changes and anthropogenic changes, and climate models. (Which reminds me, Holton has a chapter about numerical modelling) Other books, a little less heavy on the detailed math: Earth's Climate - Past and Future - William F. Ruddiman The title says it all. A lot of good information. Essentials of Meteorology An Invitation to the Atmosphere - C. Donald Ahrens. An introductory level, perhaps too introductory if you've understood a fraction of what I've been saying (then again there are some good climate maps in the back and other interesting things). Snow Ball Earth - Gabrielle Walker For geology books that have some paleoclimatology in them, there's: Evolution of the Earth - Dott and Prothero Ontario Rocks - Nick Eyles
130739. Quietman at 10:10 AM on 6 November 2008
        It's the sun
        chris On CO2 entering or exiting the water. That is an assumption. There is no way to know if that is a fact. You like to say lets not pretend to not know what we do know. In this case lets not pretend to know what we dont know. Given the current state of tectonic activity under the surface of the oceans there is no way in hell you can know what direction CO2 is travelling. Did you actually read any of the articles that I gave links to? In this same argument at Live Science I was challanged to provide just 20 papers by scientists refuting AGW. When I provided links to 20 papers (not articles) I got the response that over half were not peer reviewed. They were not peer reviewed because of fear. This buddy review system means that if you don't agree you must be wrong. Rhodes Fairbridge was wrong because he was not peer reviewed. Here's a news flash for you, he was not peer reviewed because he had no peers. The man was a genius. Spencer gets knocked for his religious beliefs. I don't share his belief but I don't call him crazy for it. That is what is known as grasping at straws.
130740. Quietman at 09:48 AM on 6 November 2008
        It's the sun
        rob Your comment 188 had me laughing. Not at you however. It's the way you worded your statement. I do appreciate a good jab on occasion.
130741. Quietman at 09:41 AM on 6 November 2008
        It's the sun
        Mizimi I was thinking of safety, my grandchildren are 6, 4, 2 years and the latest 3 weeks old. I don't want to see them fall into a plain glass pane. I had in mind green translucent fibreglass for the roof and clear double pane 3'x 5' anderson casements mounted sideways for the walls. The andersons wont cost anything as they are currently on the house and I am replacing them with something easier to maintain. It's the roof panels that I am not sure about. Any thoughts?
130742. Mizimi at 06:35 AM on 6 November 2008
        Water vapor is the most powerful greenhouse gas
        Around 55% of the world's electrical energy is produced from coal (some 8 terawatts) and during that generation the approximate amount of water evaporated from cooling towers is about 25 million million tons/yr. or 25,000 billion tons...much the same as the CO2 from ALL fossil fuel combustion. And that figure does not include the water produced by combustion. The amount of WV varies according to time of day and load/location and network switching; but as coal fired stations are more difficult to modulate, they tend to be run as 'mainstay' providers, with oil or gas stations 'topping up' as necessary. That WV is generally enitted at around 100 to 200 meters above ground ( dependent on the type of cooling tower) and then drifts according to prevailing wind. That drift can exceed 2000 kilometers in 7 days ( average time before precipitation). So the next door country tends to get your WV ( rather like acid rain). Also, in another thread, Dan Panburn mentioned a paper which suggests the re-radiation of IR occurs within about 100 mtrs of the emitting body and thereafter conduction/convection take over. If this is the case, then adding substantial amounts of WV at relatively low altitudes would have an immediate warming effect which perhaps would be limited geographically by the WV 'shadow'. ????
130743. Dan Pangburn at 15:16 PM on 5 November 2008
        Models are unreliable
        Chris apparently has no knowledge of dynamic system theory. That helps explain the overt hostility (under the false assumption that I am just making stuff up) and why he/she mistakenly declares that some of my assertions are erroneous. Dynamic systems with feedback are phenomena of the natural world, like thermodynamics, genetics, cosmology, etc. etc., which can be studied and understood. The subject is studied by some engineers; usually as part of a post graduate course. They study the phenomenon and learn concepts and applicable mathematic tools and usually apply them to things like the guidance system of an antimissile missile, cruise control device for a vehicle, etc. Learning about dynamic systems is not required for climate scientists. They appear to be totally unaware that knowledge of dynamic systems would drastically alter their perception of world climate. Knowledge of dynamic systems allows recognition that world climate, as summarized by average global temperature, can be viewed as a dynamic system and that the mathematics and concepts of dynamic systems apply. Some things are immediately obvious to anyone familiar with dynamic systems with feedback. For example, the existence of temperature downtrends proves that significant NET positive feedback does not exist. Failure of climate scientists to recognize this stems from a lack of knowledge of that part of science pertaining to dynamic systems. Incidentally, a lack of knowledge of dynamic systems resulted in misinterpreting the meaning of ‘input’. Input to a dynamic system refers to the input to the transfer function. This input is not merely the output of the source of energy (as Chris erroneously guessed), which in the case of climate is the sun, but also includes any and all feedbacks (the combined effect of which is NET feedback). Also, lacking an understanding of dynamic systems can result in the delusion that world climate is somehow special and does not follow the same (dynamic system theory) rules as other dynamic systems. The output of this dynamic system model is average world temperature. The transfer function is by definition a function that accounts for all factors that influence average world temperature. Lack of understanding of dynamic systems with feedback has resulted in a repeat of stuff that no one that is knowledgeable on the subject disputes and a failure to realize that temperature downtrends prove that substantial negative feedback must exist because the NET feedback can not be significantly positive. Temperature observations are widely available. They show temperature downtrends when there is no significant influence from Milankovitch. This could not take place (without change to influence from outside the planet) if there were any net positive feedback. Without the imposition of net positive feedback by the GCM users, the GCMs do not show significant global warming. Other shortcomings of GCMs and their use are described at 32 above. Any good reference on dynamic system theory and application would serve to learn how dynamic systems work. As a start, one might review the applicable chapters in Phelan, R 1967, Dynamics of Machinery McGraw Hill Book Co. NY. Although the subject is presented in the context of control systems it is readily generalized to apply to global climate and global average temperature.
130744. chris at 06:29 AM on 5 November 2008
        The Mystery of the Vanishing Ocean Heat
        Re #24: HealthySkeptic - Thinking of something silly and then asserting that that's what the scientists must have done, isn't skepticism…it’s not healthy either – allowing yourself to be used as conduit to service someone else creepy agenda is not good for you! …There are lots of problems with your little post: (i) The IPCC doesn't make measurements, and I'm pretty sure it didn't "choose a location like Hong Kong, which is subsiding, to collect sea level data" (can you source that idea please?). Scientists make measurements, and they publish their data. The role of the IPCC is to make a detailed compilation of the scientific data and to present this in reports such that the complex science can be appraised by policymakers and the public alike. (ii) The data on sea levels from tide guages, comes from 100's of tide guage locations. In fact there are probably 1000's of these, but since it would be foolish to use tide guage measurements from regions where the geophysics, in relation to isostatic post glacial rebound effects or subsidence, is poorly defined, many of these are eliminated from analysis. So as Douglas and Peltier stated in a review some years ago: "Tide guages in Alaska, Japan, India, and many other areas have long records that are unusable because of vertical uplift or subsidence associated with seismic activity or crustal deformation" BC Douglas and WR Peltier (2002) The puzzle of global sea-level rise. Physics Today 2002, 35-40. And so, for example, a recent analysis of the rate of sea level rise throughout the 20th century century analyzed data from a set of tide guages that numbered around 50 in 1900, rising to around 100 in 1940 and 300 in the 1990's. Tide guages data were only used where reliable assessment of non-sea level change contributions were determined either to be minimal or assessable [*] [*] J. A. Church & N. J. White (2006) A 20th century acceleration in global sea-level rise. Geophys. Res. Lett 33, art # L01602 (iii) The IPCC isn't trying to "prove" anything. Its role is to summarise the scientific data periodically so as to inform policymakers (and anyone who cares to take advantage of an incredible resource) of the science. I suspect that it might be you that is trying to "prove" something! Anyway it's very easy to compare the IPCC reports with the original scientific data, and so (if one is sufficiently interested) to determine whether the IPCC reports are a faithful assessment of the science.
130745. chris at 04:07 AM on 5 November 2008
        It's the sun
        re #186/187 rob, the sun certainly keeps us snug, but it hasn't made any significant contribution to the marked warming of the last 30 odd years! (i) remember that the paper that indicates high solar activity "over the past 60 years" in the context of the previous 1150 years (Usoskin 205; link in John Cook's top post), only addresses the relationship between solar output and the Earth's surface temperature up 'til 1975. Since that time the solar output has been tending downwards a tad, while the Earth's surface temperature has gone up markedly. As the authors indicate, variations in solar outputs can't have made a significant contribution to the marked warming of the last 30-odd years. (ii) Storage heaters once warmed up and disconnected from their energy supply do continue to release heat through the next day (they're full of bricks!), but the maximum heat release after disconnecting from the mains occurs immediately, and then drifts downwards (an exponential decay of release of thermal energy as the heater tends towards a new equilibrium temperature equivalent to ambient temperature - it's slightly more complicated since the ambient temperature isn't constant and in any case is (hopefully!) responding to the hot bricks). So the oceans may release thermal energy stored following a period of high solar output, but the maximal rate of release of thermal energy should occur pretty soon following a downward drift in solar output, and this release of thermal energy will drift downwards much like your storage heater. However that's completely contrary to the temperature record. The solar output maxed around 1950, and since then has been pretty constant, drifting downwards a tad in the last 20-odd years [see, for example, Mike Lockwood and C. Fröhlich (2008) "Recent oppositely directed trends in solar climate forcings and the global mean surface air temperature. II. Different reconstructions of the total solar irradiance variation and dependence on response time scale"; Proceedings of The Royal Society A 464, 1367–1385; as well as the long list of similar studies linked in John Cook's top post under "Other studies on solar influence on climate"]. A storage heater doesn't hold onto all of its heat for a long, long period before starting to release it. Neither does the ocean. (ii) Another difficulty with your argument relates to the "top of the atmosphere" radiation budget. I’m pretty sure that satellite monitoring of solar irradiation and that returning from space shows an imbalance (‘though need to hunt down the relevant papers). There's excess solar energy being retained in the climate system, consistent with greenhouse gas warming. If the warming was due to some magical delayed release of stored thermal energy in the oceans, one would expect a top of the atmosphere balance of solar and re-radiated energy, or even a slight excess dissipation of energy into space. I don't think the data supports that interpretation. (iv) Notice that the temperature hasn't declined since 1998. The temperature has been on a rising trend from the mid- 1970's, through the 1980's, 1990's and early 2000's. The surface temperature in 1998 was lifted by around 0.2 oC above the trend by the strongest El Nino of the 20th century [see, for example: http://data.giss.nasa.gov/gistemp/2005]. In such an event solar thermal energy absorbed by the ocean surface is anomalously spread over vast tracts of the Western Pacific and Indian ocean to the Eastern Pacific and the S. American coast, combined with the suppression of cold water upwelling along the Western S. American coast. This gives us a marked but transient upward jump in the Earth's surface temperaure. In 2005 we pretty much reached the 1998 surface temperature without the large temperature enhancement of a strong El Nino. So the temperature was still trending upwards through 2005... (v) Note also that the increased surface temperature resulting from enhanced greenhouse gas concentrations relates to the new equilibrium temperature corresponding to the Earth’s new “balance” in response to an enhanced forcing. But of course both at equilibrium, and during the “journey” towards the new equilibrium, stochastic (and non-stochastic) elements of the climate system introduces “noise”. So we don’t expect a perfect progressive increase in temperature as greenhouse gas concentrations rise. We only have to look at the temperature record to see that the marked warming of the last 30-odd years constitutes a rising trend “overlaid” with noise that takes the year on year temperature on short upwards and downwards excursions. (vi) Note also that while changing solar output or the very slow cyclic drift of the Earth's orbital properties that underlie the ice age cycles does cause CO2 to re-equilibrate somewhat from the oceans to the atmosphere, this effect is very, very small in the context of current rising atmospheric CO2. So while atmospheric CO2 levels rose by around 90-100 ppm during the 5000 years of the last glacial to interglacial transition (in response to a temperature rise of around 6 oC), we've had a 70 ppm rise in atmospheric CO2 since the start of the 1960's. So atmospheric CO2 is rising more than 100 times faster now than during the ice age transitions that are the best example of your scenario of heat-induced release of CO2 from the ocean. And of course we known that CO2 isn't coming out of the oceans in response to warming. CO2 is being forced INTO the oceans in prodigious amounts.
130746. Quietman at 12:04 PM on 4 November 2008
        Arctic sea ice melt - natural or man-made?
        "Introduction to Geophysical Fluid Dynamics" by Benoit Cushman-Roisin, 1 new from $361.71 9 used from $175.00 so I think I will skip this one unless the library has a copy.
130747. Quietman at 11:59 AM on 4 November 2008
        Arctic sea ice melt - natural or man-made?
        Patrick Thank you. The small part of that I managed to understand was interesting. Also thanks for the references. I will see if I can locate a used copy of "Introduction to Geophysical Fluid Dynamics" by Benoit Cushman-Roisin as it sounds like it may illuminate some questions I have.
130748. rob at 11:38 AM on 4 November 2008
        It's the sun
        chris at 09:48 AM on 7 October, 2008. If CO2 is the driver why has the temperature declined since 1998 when CO2 is still increasing. It`s the sun you fool, sun warms the oceans, which warm the land mass, you know, the gulf stream, warm oceans release CO2, sun goes dormant, oceans cool, land temps decline, CO2 also begins to decline, simple.
130749. rob at 11:26 AM on 4 November 2008
        It's the sun
        Might the heating of the oceans (which cover 75% of the planet and are the largest heat reservoir on the planet) by a sun that has been more active over the past 60 years than anytime in the previous 1150 years have something to do with the continuing rising temps from the late 1970`s till 1998. You know common sense, err, storage radiators of the 60`s, heat them up at night get heat all through the next day. Are you dumb enough to expect all the accumulated heat in the oceans to disappear overnight just because the heaters been turned off, of course the correlation is still sound. Pity you did not show the graph ending at 2008.
130750. Patrick 027 at 05:08 AM on 4 November 2008
        Arctic sea ice melt - natural or man-made?
        Returning to isolated vortex superimposed on pv or av gradient: One can see (unless the following is wrong*) that there must be some tendency for the relative vorticity 'center' to be displaced from a center of total state PV or AV; with basic state PV or AV increasing to the north, then (in the northern hemisphere) a cyclonic PV/AV anomaly has an associated relative vorticity (RV) anomaly that is displaced to the south relative to the higher PV/AV values in the total PV/AV 'bump', so the wind field will advect the PV/AV anomaly to the west. For an anticyclonic PV/AV anomaly, the RV anomaly is displaced in the opposite direction from the lower values of PV/AV in the total PV/AV 'dent', but the direction of the winds is reversed, so again the anomaly is advected to the west. For a circular vortex, the wind decreases with distance. If the central PV/AV anomaly is balanced by a ring of opposite sign then the wind field can be even more limited. I started to draw this in the case of a vortex of entirely one sign of vorticity; Associated with the westward motion, the growth of anomaly to the west is of the same sign. There is growth of anomaly to the east which is of opposite sign, however (the energy of waves can propagate differently from wave phases by creation or growth of new phase lines). The anomaly growth is strongest along the east-west line where the anomaly winds are more north and south rather than east-west, and is inversely proportional to distance from the center, outside the region of initial anomaly PV/AV. Because of the rotation due to the variation in vorticity in two dimensions, the contours are distorted from a symmetrical wave shape. I have read that vortices may oscillate around their average propagation. The rotation could also cause the new anomaly phases to wrap around a bit, causing an overall tilt to phase lines and opposite tilt to the the extent of disturbances (??). If a vortex is strong or compact enough relative to the basic state gradient, as mentioned before, PV/AV contours may be closed; this tends to start off of center, toward higher basic state PV/AV for positive anomaly and opposite for negative (notice the potential geometric analogy to the trajectory/streamline relationships for propagating cyclones/anticyclones). To the extent that the PV/AV is conserved and not mixed, such closed loops, tending to act as material lines, can be though of as trapping fluid. Thus, unlike the essential aspect of waves, there is some fluid that must propagate with the disturbance. Also, for shorter wavelength Rossby-wave disturbances that might occur within the vortex, they would tend to propagate along such contours and would thus be trapped within the vortex. They might be able to tunnel out to some degree because the wind field can extend farther than the vorticity field; this will be more true for longer wavelengths than shorter wavelengths (the wind at a given distance being less sensitive to fine-scale vorticity variations). My understanding is that, to the degree that a vortex can radiate mechanical waves, it loses amplitude. If some mixing is allowed so that contours can reconnect, then this process could be associated to a vortex propagating towards greater basic state vorticity of the same sign (or reduced basic state vorticity of opposite sign), shedding it's outer layers, until the core eventually reaches basic state vorticity equal to the total vorticity within the original core. (If mixing is not allowed, this couldn't happen with the closed contour 'core' of the vortex - if it still propagates in the same direction, the countours would press up against each other, trapping, stretching and tinning out regions of other vorticity values.) --- Interesting questions: What about a checkerboard pattern of vorticity anomaly - proportional to cos(ly)*cos(kx)? What about such a pattern which is tilted at some angle? --- What about distortion of waves due to differential propagation and wind? The relative vorticity associated with a westerly jet is such that the poleward AV gradient is enhanced across a westerly jet; it is reduced across an easterly jet or relative minimum in westerly winds. (PS in case it wasn't clear before, a westerly wind is eastward (it comes from the west). A northerly wind is from the north. Etc.) Thus, Rossby waves' phase propagation through the air should be faster to the west within a westerly jet. This would oppose the tendency for the winds to carry the Rossby wave phases faster to the east within the jet. Supposing the advection of Rossby waves by the wind is the stronger effect: what would happen? To the north of a westerly jet, a north-south oriented wave phase line would become tilted northwest-southeast, and any that are tilted from northwest to southeast would be distorted such that the wavelength is reduced. Oppositely tilted waves would have their wavelengths increased and also get tilted toward being north-south. Mirror image on the other side of the jet. The zonal wave number is unchanged but the meridional wave number varies. ... Well without going into all the details, the effect, which would be different for different wavelengths, would be to alter the group velocities of the waves. Conceivably one portion of the spectrum might be pulled into a westerly jet (?)(causing it to meander with those wavelengths?) while another portion would be pushed away, and maybe the reverse for an easterly jet or relative minimum in the westerlies (?)

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