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Comments 130601 to 130650:

130601. Dan Pangburn at 01:18 AM on 14 December 2008
        CO2 lags temperature
        During the last and previous glacial periods there were temperature and carbon dioxide up-trends and downtrends. Credible data from Vostok and EPICA showing these trends are readily available (e.g. the first graph above). Close examination of these data shows unequivocally that on many occasions temperature trended down for centuries while carbon dioxide level was higher than it had been during a prior temperature uptrend. This shows that, at least at that time, temperature was not driven by carbon dioxide level. It is well known that added increments of carbon dioxide have less influence than previous increments. This has been elucidated using the added-blankets metaphor. Since there is more carbon dioxide in the atmosphere today than during the glacial periods, added increments of carbon dioxide today have even less influence than they did during the glacial periods when they did not drive temperature. Thus added atmospheric carbon dioxide today does not drive temperature and AGW that is based on increased atmospheric carbon dioxide is a mistake.
130602. Quietman at 16:59 PM on 13 December 2008
        We're heading into an ice age
        Mizimi Plates literally float. They can shift, rise or fall. There are no true continents, what we see is a result of large pieces of lighter material breaking and mergeing or subducting. There is no real difference between sea floor and land other than elevation. So while Australia is relatively free from volcanism it is still subject to plate tectonics which are constantly active but change intensity and speed is cycles.
130603. Tom Dayton at 14:31 PM on 13 December 2008
        Water vapor is the most powerful greenhouse gas
        There's a new satellite-based study of the relationship of water vapor to CO2 by Dessler and colleagues on NASA.gov (the Earth section). It nails down the specific feedback effect's size.
130604. chris at 06:27 AM on 13 December 2008
        Human CO2 is a tiny % of CO2 emissions
        It hasn't been far-off 300 ppm (generally a bit lower)for millions of years (around 20 million years), apart from the glacial periods of the past few million years when atmospheric CO2 dropped towards 180 ppm. That's what the evidence indicates. see papers cited in post #13 above...
130605. Patrick 027 at 16:17 PM on 12 December 2008
        Arctic sea ice melt - natural or man-made?
        CORRECTION " (**The component of Group velocity parallel to phase lines - amplitude propagation along phase lines - is fastest at intermediate tilts between phase lines being aligned with the PV gradient and being perpendicular to it**). " Actually, that's for the group velocity y-component with basic state PV gradient parallel to y. The fastest group velocity component parallel to phase lines occurs when the phase lines become parallel to basic state PV contours. Of course, for finite-width wave envelopes, this should be equal to phase propagation of the same wave described instead as having phase lines aligned with the PV gradient, with amplitude varying sinusoidally along phase lines... etc. ------------ A wave envelope can be limited in multiple dimensions. In **C0** in was limited in the x direction. One could consider the case of a wave envelope limited in both x and y, in which case aspects of **C0** and **C1** would be combined; there could/would be group velocity in both x and y; new phase lines would grow on the outskirts in the x direction (in the direction of group velocity minus phase motion - if the wave envelope is not spreading out too quickly, then old phase lines will decay on the other side of the wave envelope). ---------- Group velocity: THE group velocity of a wave is determined by the frequency as a function of the spectrum - specifically, it is in (x,y) space equal to the gradient of w in wavenumber space (k,l) (and so on for three dimensional waves, etc.) - thus it has components that are partial derivatives dw/dk and dw/dl. ----- (I'm using d for partial derivatives here but partial derivatives are written with a "del" symbol (not the same as the gradient operator symbol, which I believe is called "Del", which is an upside down capital greek letter Delta; the del symbol looks a little like the lowercase greek letter delta, but is smoother - it looks like a backwards '6'. I also used 'd', as in 'dw','dk','dl' above, as values (representing a difference in w, k, or l) that may or may not be infinitisimal in size. The propper symbol to use in that case is the lowercase delta, or particularly for sizable differences, capital Delta. I'm going to continue to just use dw, dk, and dl here, though.) ----- But in order to actually see amplitude propagation (wave envelope propagation) at the group velocity, there must be variation in amplitude. This can be produced by linear superposition of additional waves that or only infinitesimally different parts of the spectrum. In that case, amplitude variations are very spread out in space and the group velocity of the interference pattern is about the same as (dw/dk,dw/dl). However, as the amplitude variations become more concentrated in space, the ratios of the differences of w to the differences of k and l between wave pairs won't be exactly the same as the derivatives dw/dk and dw/dl for each linearly-superimposed component - and each component may have different dw/dk and dw/dl for it's own k and l. While a wave envelope will propagate with some average or effective group velocity, it will also tend to spread and weaken (or contract and intensify up to a point and then spread and weaken - one or the other might happen in one direction while the opposite happens in another direction) and the phase lines may take on different tilts in different parts of the wave envelope, which might then be described by multiple overlapping wave envelopes, etc..., as there are a range of group velocities present. While wave envelope propagation perpendicular to phase lines can always be seen as being at a group velocity component in that direction, the group velocity along phase lines may lose any meaningful distinction with phase propagation, as in the checkerboard pattern example; this suggests (at least for Rossby waves) that the group velocity component parallel to phase lines will get smaller when the wave envelope wavelength in that direction get's smaller, just as phase speed is smaller for smaller wavelengths, and as described for the checkerboard pattern, both propagation of phases or along phases each vary qualitatively the same way with wavelengths in both directions.
130606. Patrick 027 at 16:13 PM on 11 December 2008
        Arctic sea ice melt - natural or man-made?
        ... In **CASE C2**, the checkerboard pattern - the nodes of the vorticity wave, u' wave, and v' wave, form a set of rectangles for each wave. Contours of wave values thus are nearly rectangular near the nodes but become more rounded toward the centers of the rectangles. In this checkerboard pattern, parallel to either set of parallel nodes, wave values vary sinusoidally. In the x direction, the u' and vorticity waves are in phase and 180 deg out of phase (depending on y), while they are 90 deg or 270 deg out of phase in the y direction. In the y direction, the v' and voriticity waves are in phase and 180 deg out of phase (depending on x), while they are 90 deg or 270 deg out of phase in the x direction. Because of the constant proportionality in the x direction of u' with vorticity and in the y direction of v' with vorticity, the propagation in the y direction does not vary with x and the propagation in the x direction does not vary with y. (The propagation of the wave of course occurs as u' and v' act across the PV gradient to increase PV where the PV anomaly gradient is in one direction and decrease the PV where a component of the PV anomaly gradient is in the other direction; a maximum moves toward where values increase and away from where values decrease, a minimum moves toward decreasing values and away from increasing values; the derivative in space of a sinusoidal waveform is another sinusoidal waveform either 90 or 270 deg (depending on view point) out of phase; a moving sinusoidal waveform produces variations at fixed locations that are sinusoidal in time, etc, so propagation of a otherwise unchanging wave pattern will have rate of change of PV, RV, u', v', etc, 90 or 270 deg out of phase (in the direction(s) of propagation) from the wave pattern of the instantaneous values of PV, RV, u', v', etc, respectively, and with the amplitude of the time derivative wave in proportion to the amplitude of the instantaneous value wave - a proportion that can vary in the direction of propagation but does not vary in the perpendicular direction). -- But what about **CASE C1**, or more generally, when a wave does not form an infinite pattern but has only nonzero amplitude (or amplitude above OR below some threshold) in a single limited region that is not part of a repeating sinusoidal variation (or some linear combination of those) of amplitude? (PS this does not describe any propagation of the checkerboard pattern; the modulation of amplitude of one wave by another sinusoidal function has a group velocity but this is not the group velocity of the whole pattern; to illustrate such a group velocity, one must multiply the whole wave form by yet some other amplitude-modulating function, etc...) Take **CASE C1** for example. The vorticity wave is a wave train along the x-axis, symmetric about y, that is nonzero only over some finite range of y. If the basic state PV gradient is not parallel to either axis, as in **CASE C1b**, then the wave is tilted and the 'amplitude wave' (better term - the wave envelope) will move with some group velocity in y that is a function of the wavelength in x (and therefore a function of wavenumber k), where the group velocity y component is precisely the derivative dw/dl for the k value - w is a function of (k,l) for Rossby waves and waves in general; this is how group velocity can be defined for a wave that is not part of a specific interference pattern of specific waves). In **CASE C1a**, the y component of group velocity is 0; the wave envelope doesn't propagate in y. The physical explanation is qualitatively the same as in **CASE C2(b and a, respectively)**. A narrow wave envelope should slow propagation in the x direction for the same reason that k affects propagation in y and l affects propagation in x for the checkerboard pattern. But that is only part of the story. In both **C1a** and **C1b**, as in **C2**, there are closed wave streamlines around the wave vorticity maxima and minima, as there are u' and v' waves. But in **C2**, both u' and v' reach maxima and minima along the nodes of the vorticity wave, and there values go toward zero approaching the next vorticity maxima or minima. In **C1**, in the y direction, there is not other vorticity maxima or minima. Instead, u' and v' values must decay toward zero going away from the center of the wave envelope - Refering back to how the wind field can be determined from the vorticity field, the length scale of this decay to zero will increase with increasing wavelength in the x-direction (note consequences for group velocity, this is somewhat** qualitatively similar to how k affects propagation in y and l affects propagation in x for the checkboard pattern, though perhaps for additional reasons). Outside the vorticity wave envelope, this wind field must also be irrotational; this works because while -du'/dy must reverse sign (in the y direction) in order for u' to decay to zero, dv'/dx can keep the same sign out to large |y| (though it approaches 0 as v' approaches 0). One can get a qualitative handle on this (and some of the other issues discussed above, including group velocity of tilted waves) by considering each phase line as a string of circular vorticies (remember that the wind speed of each is inversely proportional to distance from the center of each). Each contributes to the wind field v' in between vorticity maxima and minima phase lines, and not just at points on the same y value as the vortex; hence, v' is larger at any one y value due to voriticity at other y values (though the vorticity at the same y will have the greatest effect). Meanwhile, the u' fields of any pair of vortices also adds to increase total u' outside the pair but the values partly cancel in between the pair (with the total u' from that pair being of the sign of the u' from the stronger of the two vorticities). And so on... vorticity phase lines of constant amplitude over y has constant v' over y as well, zero u', and if only one line of vorticies, v' would be constant over x on either side of the line. But variation of vorticity amplitude along a phase line allows nonzero u' (as described above for both cases **C1** and **C2**, thus allowing some propagation in the y direction if there is a PV gradient in x ----- [PS another way to look at that: suppose instead of holding x and y oriented to the wave structure, hold x and y so that the PV gradient is just in y, but the wave is tilted. The wind field of each vortex will, by displacing PV contours, increase PV on one side and decrease PV on the other, with zero PV change along a line in the y direction centered on the vortex. In a tilted wave, the vortices along a phase line (along a vorticity wave crest or trough) lie in each other's PV changing regions. Where their is constant amplitude along the phase line or where there is an amplitude minimum or maximum (constant amplitude at that point), provided symmetry about that maximum or minimum, then the effects cancel and there is zero PV change at that point, but where vorticity is not symmetric along the phase line about a point, or generally where vorticity changes along the phase line or changes sign, the effects at the location of one vortex by the other vortices can be or will be unbalanced, so that PV is changing at that point along the vorticity crest or trough, hence there can be or will be amplitude propagation in the direction parallel to phase lines]. -----), and variation of v', but unlike **C2**, where the v' is kept proportional to vorticity over y, for **C1**, the parts of the wave near y=0 may generally have less v' per vorticity as there is on the edges of the vorticity wave envelope - the stronger vorticies have proportionately weaker v' at the same y due to the weaker vortices at other y values, while the weaker vortices have stronger v'. Furthermore, outside of the vorticity wave itself, there is still v' (and u') from the vortices within the wave envelope (that their magnitudes decrease faster with distance from the vorticity wave envelope for shorter wavelengths in the x direction (higher k) can be seen as a consequence of the wind field at any one point depending less on the finer details at some distance). This means that, initially, phase propagation speeds (in the x direction) are slower in the center of the wave envelope as they are on the outskirts. This means the waves bend into V or U shapes (and the wave envelope expands due to the extent of v' (and u' for **C1b**)). The wave is tilted relative to (x,y), above and below y=0, in opposite directions. This bending then allows for amplitude propagation away from the center (where the amplitude falls) and toward the wave envelope edges; for **C1a**, this is symmetrical about y=0, for **C1b**, the variation of basic state PV in the x direction can introduce some asymmetry - the tilts relative to the PV gradient direction won't be equal and opposite; conceivably they might be the same sign; they can't have the same magnitude, though; ----- (**The component of Group velocity parallel to phase lines - amplitude propagation along phase lines - is fastest at intermediate tilts between phase lines being aligned with the PV gradient and being perpendicular to it**). This could be seen as two wavetrains of equal and opposite phase tilts relative to x,y directions, but with wave envelope aligned in the same direction, that were initially linearly superimposed, but then seperated as each had it's own group velocity (and possibly different phase phase speeds, if the PV gradient is not parallel to y). However, each of these wavetrains can be expected to undergo the same process (modified by different phase tilts, etc.) as occured with the original wavetrain. Alternatively, depending on wave envelope form, there might never be complete seperation (thought the amplitude at the center will continually decrease) - the wave might continue to spread with a range of group velocities (corresponding to those group velocities of all linearly superimposed component waves) with the phase lines curving into U shapes. Another way of veiwing this is to consider a string of vorticies of alternating sign (representing the wave train, aligned with the wave envelope); rather than consider the motion of the vorticities, one can think of it as vorticities that are not moving but with each generation of vorticity phase lines continually producing a new generation of new vorticity crests and troughs that are 90 or 270 deg out of phase from the parent generation. The total wave propagates because the third generation is 180 degrees out of phase from the first, as is the forth from the second, etc, so that they cancel each other. But with amplitude confined to a wave envelope centered at y=0, any generation will produce a next generation that is more spread out in y and has lower amplitude at y=0. Thus the third generation does not completely cancel the first at y = 0, but that allows a portion of the first generation to continue to act to produce an additional second generation (generation 2B ?), and so on... so that the first generation might eventually be canceled out, but by that point ... etc...
130607. Dan Pangburn at 12:18 PM on 11 December 2008
        Models are unreliable
        Contrary to the statement in post #80 “No one says that "all temperature trend direction changes are brought about by Milankovitch cycles", so let's not make stuff up”, the statement “So it's quite straightforward to understand how the net insolation effect can produce a pattern of cyclical temperature variation as observed in the record” and several similar statements in post # 80 indicate that Chris seems to realize that temperature up trends and downtrends were not driven by atmospheric carbon dioxide level in the past. In post #73 with the statement “We all know that the Earth's equilibrium temperature response has a logarithmic relationship to the atmospheric CO2 concentration” Chris appears to also understand that added increments of carbon dioxide have diminishing influence on temperature. But then Chris and apparently the rest of the alarmists fail to put the two observations together which would prove to them that temperature trends now are also not driven by atmospheric carbon dioxide level.
130608. Quietman at 11:20 AM on 11 December 2008
        A Great Science Fiction Writer Passes - Goodbye Dr. Crichton
        This is what "State of Fear" is about and like all of Michaels works is based on his investigations and conclusions drawn from same and then voiced in the form of a novel. It was one of, if not his best, works. The following is a paragraph from environmentalism as a religion in a speech at the Commonwealth Club, San Francisco, CA, September 15, 2003 How will we manage to get environmentalism out of the clutches of religion, and back to a scientific discipline? There's a simple answer: we must institute far more stringent requirements for what constitutes knowledge in the environmental realm. I am thoroughly sick of politicized so-called facts that simply aren't true. It isn't that these "facts" are exaggerations of an underlying truth. Nor is it that certain organizations are spinning their case to present it in the strongest way. Not at all---what more and more groups are doing is putting out is lies, pure and simple. Falsehoods that they know to be false. Thank you Michael. R.I.P.
130609. Patrick 027 at 05:28 AM on 11 December 2008
        Arctic sea ice melt - natural or man-made?
        Correction sec.2e.: **CASE C2a**: Now, in this case, if the basic state PV gradient is in the y-direction (the 'default setting' for this overall discussion), then for Rossby waves, dw/dl should be zero at l=0. There is *** N O T *** 'amplitude wave' propagation in the y direction; the phases propagate in the negative x direction.
130610. Tom Moore at 00:24 AM on 11 December 2008
        Latest satellite data on Greenland mass change
        At face value, the graph suggests that there was a mass gain going on until quite recently, perhaps 2005. If so, this past couple of years doesn't seem like much to worry about.
130611. Philippe Chantreau at 18:46 PM on 10 December 2008
        Arctic sea ice melt - natural or man-made?
        I wouldn't hold it against you Patrick... Quietman, you may be right about Arkadiusz, or not. I am still unimpressed with Beck, especially his fantasy graph on Dansgaard-Oeshger cycles. Has he withdrawn that piece of work from his web site? Has he explained what the change in the x axis mean? Arkadiusz, what degree have you earned from which institution and what are your publications? Those are the things that will tell me if you are a "scientist", as Quietman states. I do applied science too (in another area), and would certainly not consider myself a "scientist."
130612. Patrick 027 at 16:08 PM on 10 December 2008
        Arctic sea ice melt - natural or man-made?
        PS a little unsure of my section 2d above.
130613. Patrick 027 at 16:04 PM on 10 December 2008
        Arctic sea ice melt - natural or man-made?
        Rossby Wave Wrap-up 1a. Linear superposition: For any amplitudes, multiple sets of vorticity anomalies have multiple wind fields associated with them, and each adds linearly to produce a total vorticity anomaly field with a total wind anomaly (which can be added to the basic state vorticity and wind to get total vorticity and wind). For relatively weak amplitudes (where displacments are relatively small compared to wavelength and variations in the basic state), the changes in vorticity over time due to potential vorticity advection by the wind field (which results in propagation of the vorticity anomaly patten) can also be approximated with linear superpositions of multiple vorticity anomaly patterns - each propagating in it's own way. However, the changes in potential vorticity anomalies are due to the displacements of potential vorticity contours. When displacements by all waves are along the same direction (with anomaly wind vectors purely parallel to that direction, such as occurs with vorticity waves with no variation in amplitude along the length of infinite phase lines), and with the basic state PV gradient (or at least the component parallel to the wind anomalies) constant along the same direction, and assuming constant ratio between PV anomaly and RV anomaly (it could vary due to different degrees of divergence and convergence due to ...), then the total displacement is equal to the sum of displacements of individual waves and the total resulting change of PV is the same at any x,y point, so the waves can still be linearly superimposed. However, more generally, there can be nonlinearities that arise because, 1. if the PV gradient varies along the direction of displacement, then the PV gradient can be changed at a fixed location by that displacment; an additional wave acting at the same location is no longer acting on the same PV field. 2. as the PV field is displaced by the anomaly wind, changes in the PV gradient can be produced (such as by variation in anomaly wind along phase lines) so that the change in PV produced by the next anomaly wind added are not proportional. 3. variation in amplitude of a vorticity wave along phase lines requires some closed streamlines - the anomaly wind varies in direction. PV contour displacements in one direction can alter the PV gradient in another direction. 4. Maybe some other things I haven't thought of yet. ** In particular, in the case (**CASE C1a** for future reference; **CASE C1b** will refer to a case when the PV gradient is not entirely in the y-direction) of a vorticity wave phase lines aligned in the y direction, phase propagation in the negative x direction, basic state PV gradient in the y direction, where the vorticity wave amplitude is a maximum at y = 0 and decays to 0 toward y = A and y = -A (while being symmetrical about the x axis), then, at y = 0, the anomaly wind only has components in the y direction, but away from the x axis, the anomaly wind also has x components. As the wave propagates in the negative x direction, setting aside the basic state wind, the air flows through the wave in the opposite direction at the phase propagation speed at y = 0, but the x component of the wave alternately varies the flow through the wave, causing the air to spend more time within one phase of the wave and less in the other, and affecting the resulting displacements of PV contours; the result is to sharpen and intensify the vorticity wave crests and spread out and weaken the vorticity troughs on one side of the x axis and the reverse on the other side. Obviously this effect must increase when the x component of the anomaly wind is large compared to the phase speed in the x direction. (Some analogy might be made to water gravity waves when the back-forth displacements are large in comparison to the wavelength; in which case the crests are sharp and the troughs are broad). Of course this change in wave form could modify the propagation itself... ---------- The vorticity wave has a wind wave, with components u' and v', in the x and y directions respectively; they will be (below somewhere) be refered to as the u' wave and the v' wave. 1b. wave numbers, phase speeds, group velocity: Remember that the wave numbers (k in the x direction, l in the y direction (though I've also seen l,m instead of k,l used), which add as vector components to give the wave vector (k,l)) are inversely proportional to the wavelength (1/k in the x direction, 1/l in the y direction, 1/(wave vector magnitude) in the direction of the wave vector, which is *THE* wavelength, in the direction perpendicular to phase lines). Because phase speeds are the speeds of phase lines and thus proportional to wavelength (equal to wavelength times frequency); the phase speeds don't add like vectors; but their inverses do. But if I ever refer to 'phase velocity', that might not be a correct term, but what I am refering to is the phase speed in the direction of the wave vector (perpendicular to phase lines). Group velocity is the motion of a pattern of amplitude variation of a wave (for a wave pattern with amplitude varying in space); group velocity is a vector that is the sum of group velocity components in the x and y direction (or any two orthogonal dirctions, such as parallel and perpendicular to phase lines). 2a. Linear superposition and patterns, group velocity: Consider waves of constant amplitude with wave numbers k and l. For waves with l = 0, phase lines are in the y direction. Waves with l = 0 but different k form an interference pattern with amplitude varying in the x direction. If the two k values are only slightly different, then the interference amplitude pattern moves in the x direction at the group velocity of the wave with a k equal to the average of the aforementioned two k values. This can be seen using one of the trigonometric relationships: 2 * cos(a) * cos(b) = cos(a+b) + cos(a-b) = cos(a+b) + cos(b-a) 2 * sin(a) * sin(b) = cos(a-b) - cos(a+b) = -[cos(a+b) - cos(a-b)] 2 * cos(a) * sin(b) = sin(a+b) - sin(a-b) = sin(a+b) + sin(b-a) OR, where sum = a+b and dif = a-b: 2 * cos(a) * cos(b) = cos(sum) + cos(dif) = cos(sum) + cos(-dif) 2 * sin(a) * sin(b) = cos(dif) - cos(sum) = -[cos(sum) - cos(dif)] 2 * cos(a) * sin(b) = sin(sum) - sin(dif) = sin(sum) + sin(-dif) ---------- 2b. So the linear superposition of: cos[(k+dk)*x - (w+dw)*t] and cos[(k-dx)*x - (w-dw)*t] is: 2 * cos(k*x - w*t) * cos(dk*x - dw*t) Which can be seen (assuming |dk| << |k|, |dw| << |w|) as: a wave cos(k*x - w*t), which has x-direction wavenumber k and angular frequency w, and phase speed in the x direction equal to w/k, (we expect w/k to be negative for PV gradient in the positive y direction), modulated by an 'amplitude wave': 2*cos(dk*x - dw*t), which has wavelength 2*pi/(dk), and moves in the x-direction with the x-component of group velocity dw/dk. There is no variation in the y-direction of this pattern. Call this **CASE C0** (This is nicely explained in Appendix A of Cushman-Roisin.) ---------- 2c. MORE GENERALLY, The linear superposition of: cos[(k+dk)*x + (l+dl)*y - (w+dw)*t] and cos[(k-dx)*x + (l-dl)*y - (w-dw)*t] is: 2 * cos(k*x + l*y - w*t) * cos(dk*x + dl*y - dw*t) Which can be seen (assuming |dk| << |k|, |dl| << |l|, |dw| << |w| **(actually, the last condition may not be necessary, but in the limit of small dw, dw/dk and dw/dl can be treated as partial derivatives of w as a function of k and l, in other words as the components of the gradient of w in k,l space) as: a wave cos(k*x + l*y - w*t), which has wave vector (k,l) and angular frequency w, and phase speeds in the x direction equal to w/k, and in the y direction equal to w/l; the phase lines have slope dy/dx = -k/l modulated by an 'amplitude wave': 2*cos(dk*x + dl*y - dw*t), which has wavelength 2*pi/[(dk^2 + dl^2)^(1/2)], and has ** group velocity (dw/dk,dw/dl) **. ----- 2d. **???(PS why is group velocity given as a vector with components in the x and y direction? These components are the velocities in those dimensions of a point on a 'phase line' of the 'amplitude wave' that doesn't (in this case, at least** - more generally the group velocity is the velocity of an 'amplitude region' which may not be infinitely long and straight) move along the length of the 'phase line', only perpendicular to it, keeping up with it. The reason why phase speeds in x and y directions don't add as vectors to give the 'phase velocity' is because they are not generally the components of motion of such a point on the phase line; rather they are the speeds of motion of the points that are the intersections of a phase line with a line parallel to the x-axis and then a line parallel to the y-axis. )???** ---------- 2e. When l = 0 and dk = 0, the pattern is: the linear superposition of: cos[k*x + dl*y - (w+dw)*t] and cos[k*x - dl*y - (w-dw)*t] which is: 2 * cos(k*x - w*t) * cos(dl*y - dw*t) Which can be seen (assuming |dl| << |l|, |dw| << |w|) as: a wave cos(k*x - w*t), which has wave vector (k,0) and angular frequency w, and phase speeds in the x direction equal to w/k, modulated by an 'amplitude wave': 2*cos(dl*y - dw*t), which has wave vector (0,dl), and has group velocity (0,dw/dl). Call this **CASE C2** **CASE C2a**: Now, in this case, if the basic state PV gradient is in the y-direction (the 'default setting' for this overall discussion), then for Rossby waves, dw/dl should be zero at l=0. There is 'amplitude wave' propagation in the y direction; the phases propagate in the negative x direction. **CASE C2b**: But if there is a basic state PV gradient in the x-direction as well, then dw/dl can/will be nonzero and there will be 'amplitude propagation' in the y direction. Physically, without reference to the motion of the linearly-superimposed components that create the pattern (though it could be understood that way as well for small amplitudes), the reason for this is qualitatively the same as **PART OF** the reason for 'amplitude propagation' in the same direction in **CASE C1b**, which is that, as the amplitude varies along phase lines, there are vorticity maxima and minima that are maxima and minima in both dimensions x and y. This means that the anomaly wind streamlines are closed loops; not only is there a v' wave but also a u' wave. u' is positive where the vorticity anomaly decreases in y and is negative where the vorticity anomaly increases in y. When the basic state PV contours are not parallel to the x-axis, this x-component of the wind displaces those contours so as to propagate variations in amplitude along the phase lines. If the x-component of the PV gradient is toward positive x, then this along-phase-line propagation is toward positive y; it is in the negative y direction for a PV gradient x-component in the negative x direction. Notice if we realign the axes with the PV gradient then the phase lines are tilted and this describes the component of group velcocity parallel to phase lines. In **CASE C2b** in particular, the u' wave has crests and troughs at the nodes of the 'amplitude wave', just as v' has crests and troughs at the nodes of the vorticity wave that occur at discrete x values (at any one time). The nodes of the wind waves pass through the vorticity maxima and minima - which is a quick way to make the judgement that the vorticity maxima and minima keep the same amplitude as they propagate along phase lines ('amplitude propagation') while the phase lines also propagate. In **CASE C0**, the group velocity is perpendicular to phase lines and generally of different magnitude and/or direction as phase propagation, which requires that, following individual phase lines, the vorticity maxima and minima grow and shrink, and reverse sign; this requires that the wind wave nodes not pass through the vorticity wave crests and troughs except at the 'crests' and 'troughs' of the 'amplitude wave'. Notice that in **CASE C2**, rather than refering to one wave field modified by 'amplitude waves', the pattern instead can be described as a checkerboard pattern of rectangularly shaped vorticity wave phases (with u' and v' wave phases also rectangular). The along-phase line 'amplitude propagation' can also be desribed as the y-component of phase propagation of this checkerboard pattern. This becomes more obvious if |dl| is not much smaller than |k| (in which case it doesn't make sense to keep the 'd' - call it l instead of dl). What is also true is that the the identification of the 'amplitude wave' can be assigned to the other part of this pattern (the part with wavenumber k), which becomes more obvious when |l| is larger than |k|. Another point that is interesting, which applies to all cases **CASE C1** and **CASE C2**, is that because -du'/dy makes a contribution to vorticity anomalies (generally with the same sign as dv/dx for the cases as described) , dv'/dx will be smaller for the same vorticity anomalies, which means that, for the same vorticity wave amplitude and wavelength in the x direction, v' wave will have smaller magnitude than otherwise, more so as the magnitude of dl increases (as the wavelength in the y direction shrinks, or more generally, as the spatial scale of the vorticity variations in the y-direction shrinks, for a given vorticity variation). (and the same for u' when the x-direction wavelength shrinks for a given y-direction wavelength, etc.) This means that for the conditions so far and for the same ratio between anomaly PV and anomaly vorticity, the propagation in the x direction will be slower for given vorticity variation over shorter y direction distances (and so on for y-direction propagation with shorter x direction distances). to be continued just a bit more... _______
130614. Wavelength at 20:58 PM on 9 December 2008
        Water vapor is the most powerful greenhouse gas
        Somewhere around 50% of the world’s CO2 and 75% of the AWV is produced by large point sources, in contrast to natural evaporation from oceans or lakes - so to me it seems reasonable to ask if this is likely to affect climate models. I have not seen it mentioned in the reading I have done. Since your previous response, I have looked on the web and found some information, such as: http://ams.confex.com/ams/88Annual/techprogram/paper_136670.htm This shows an average height of plumes above wildfires to be 2.3 km worldwide with 3 km for North America. This presumably only refers to the visible plume from particles/cloud formation, but is quite a bit below the 10-15 km that I had in mind. Also, the updraft from wildfires is probably hotter than from cooling towers, although with a lower relative humidity. The point-source question remains to niggle me. I suspect it is not significant, but still have no definitive argument to dismiss it.
130615. HealthySkeptic at 11:41 AM on 9 December 2008
        Evaporating the water vapor argument
        #27 Douglas, LOL! It is very ironic that your comment "its humor depends on the listener being scientifically illiterate or willing to make oneself temporarily illiterate for the sake of an ideology" applies equally well to the vast majority of AGW alarmists.
130616. HealthySkeptic at 11:30 AM on 9 December 2008
        Global warming stopped in 1981... no, wait! 1991!
        #16 I agree with your point (i), however I think unwarranted fear is what's being generated by some people's interpretation of the evidence... that and the media sensationalisation of the extreme, potential consequences of that evidence.
130617. Mizimi at 05:54 AM on 9 December 2008
        Human CO2 is a tiny % of CO2 emissions
        "Likewise with the Earth's atmopheric CO2 concentration. For millions of years the earth's atmospheric CO2 concentration has been in dynamic equilibrium...." So what is the 'equilibrium position' of CO2 over these millions of years? 200ppm? 1500ppm? 4000ppm?
130618. Mizimi at 05:16 AM on 9 December 2008
        Greenland was green in the past
        #5 'Iceland' is from the old Norse word meaning 'isle' co-joined to 'land' thus giving (phonetically) 'iceland'
130619. paledriver at 02:09 AM on 9 December 2008
        There is no consensus
        #88 Can you provide some links for your claims? Thanks in advance.
130620. Mizimi at 01:14 AM on 9 December 2008
        Water vapor is the most powerful greenhouse gas
        Wavelength: Air temperature decreases with altitude..this is called the 'lapse rate' and is approx -6.5C/km, so at around 5km the air temp is -13C and the pressure is about 0.5bar (half surface pressure). As WV content of air is temperature/pressure related then the amount of WV decreases as you ascend. Both these factors influence how high the plume can ascend without 'external' help from air turbulence or other factors. Therefore I would expect a greater warming effect from WV at surface level ( say up to 500metres)and then a steady decline towards zero at around 3000m
130621. Quietman at 05:15 AM on 8 December 2008
        Arctic sea ice melt - natural or man-made?
        Arkadiusz At least you are a scientist. Many of us posting here can't even say that. Personally I find your comments (and Patricks) quite interesting.
130622. Quietman at 05:10 AM on 8 December 2008
        It hasn't warmed since 1998
        Mizimi Yes and it's always GISS data used by the alarmists.
130623. Quietman at 05:06 AM on 8 December 2008
        Latest satellite data on Greenland mass change
        Mizimi Actually I would love to see it extended back to 1975, just before the current bout of tectonic activity.
130624. Steve L at 07:25 AM on 7 December 2008
        Latest satellite data on Greenland mass change
        Thanks for keeping this excellent resource up to date!
130625. Mizimi at 04:48 AM on 7 December 2008
        Water vapor is the most powerful greenhouse gas
        Wavelength: The answer is : It depends! I live 26km from a coal fired power station/cement works and when the prevailing wind is northerly I can see, out at sea a horizontal band of brown haze..the plume. On other days with higher winds it disperses more quickly and does not appear here. On still winter days smoke from local bonfires rises straight up and flattens out at around 100m and is dispersed by around 200m How high and far the plume goes depends entirely on 'local' weather conditions. Back a few years the scandinavian countries suffered 'acid rain' from british power stations.
130626. Mizimi at 04:31 AM on 7 December 2008
        Temp record is unreliable
        Your quite right Chris; apologies.
130627. Mizimi at 04:24 AM on 7 December 2008
        There is no consensus
        #88 Yes we have a lot of facts, some hard, some soft (paleoproxies for example), some incorporated into models and some unable to be included in detail (clouds and water vapour); do we know all the facts or even enough to make decisions that will adversely affect the lives of millions of people? Are those models sufficiently close to reality to act upon? Ah but, you will no doubt say, global warming will affect millions of people too.........according to those imprecise models. Recent GMT history says different. I don't disbelieve in human induced warming, I just don't accept the projected figures because it doesn't appear to be happening at the rate predicted, and those models are unable to incorporate components that have a major impact on the resultant. So why would I trust them?
130628. Wavelength at 00:31 AM on 7 December 2008
        Water vapor is the most powerful greenhouse gas
        A fine debate! Thanks to both of you. The questions are probably as important as the answers. If cooling towers are significant contributors to global warming, the alternatives to coal-fired power stations need to be reassessed. Surely there is a complication, though. The effluent from chimneys and (probably) cooling towers forms plumes, which are not only blown down-wind but also rise up through the atmosphere, cooling as they do so, remaining warmer and lighter than the surrounding atmosphere until completely mixed. I have a vague (and unsubstantiated) idea that these plumes rise to considerable altitudes – so is it possible that a large part of the AWV (and CO2) mixes into the atmosphere at the middle or top of the troposphere? Here, the influence of the AWV might be more significant… I have limited knowledge of climate modelling, so find it difficult to progress this idea. Any comments would be gratefully received.
130629. chris at 11:19 AM on 6 December 2008
        Global warming stopped in 1981... no, wait! 1991!
        Well yes HS. I'm sure we would all agree that: (i) fear isn't "the greatest behavioural driver of mankind" and: (2) that when it comes to understanding the greenhouse effect, the consequences of massive enhancement of greenhouse gas concentrations, and so on, we should consider the scientific evidence and not resort to conspiracy theorising, or pseudo-psychoanalysis. It's all about the evidence isn't it...? I hope we would all agree on that. We don't pretend that these aren't serious issues by raising ludicrous shcoolboy psychoanalytical notions about "externalising" our "untenable" "perpetual state of fear"! What's your opinion?
130630. chris at 11:02 AM on 6 December 2008
        Models are unreliable
        Come off it Dan.. 1) re "quiet sun". We're smack at the bottom of the solar cycle. Nothing surprising, or out of the ordinary, about that. For the last couple of years the very small reduction in solar irradiation has been opposing greenhouse-induced warming a tad...in a couple of years it will be supplementing greenhouse-induced warming. Not sure what point you're attempting to make about the fact that the sun is at the bottom of its solar cycle! 2) re Milankovitch cycles. No one says that "all temperature trend direction changes are brought about by Milankovitch cycles", so let's not make stuff up! Otherwise, I suspect that you haven't read the papers I cited. You need to come to some decision about whether you want to understand this stuff or not. Remember that the 100,000 year, the 41,000 year and the 23,000 year cycle are out of phase. So it's quite straightforward to understand how the net insolation effect can produce a pattern of cyclical temperature variation as observed in the record. So, for example, if the delta T or delta 18O records from the Dome Fuji or Vostok cores are Fourier transformed to extract their power spectra, the three dominant Milankovitch cycles stand out rather clearly (111 kyr; 41 kyr; 23 kyr). see, for example, Figure 2 of: Kawamura et al (2007) "Northern hemisphere forcing of climate cycles in Antarctica ove rthe past 360,000 years" Nature 448, 912-919. It really is difficult to see your problem....insolation changes due to Milankovitch cylces seem to have dominated temperature (and atmospheric CO2 concentration) variations during the ice age cycles. I suggest you have a more careful read of the article whose url you cited. It gives a pretty good account: http://www.physics.ohio-state.edu/~wilkins/energy/Companion/E16.7.pdf.xpdf Sadly, I suspect you're never going to get the simple and obvious truth that significant insolation changes due to the slow cyclical orbital properties of the Earth, can result in temperature changes that result in slow drops in temperature in advance of changes in atmospheric CO2 concentrations. Happily, competent scientists and policymakers don't seem to share your mental blockage! One of the things that you haven't commented on with respect to the temperature and CO2 changes due to Milankovitch effects, is the really very, very small changes in atmospheric CO2 concentrations [see for example: http://www.skepticalscience.com/co2-lags-temperature.htm]. So some of the changes over which you are very confused involve extremely small changes in atmospheric CO2; e.g. reductions of 10 or 20 ppm of atmospheric CO2 during several thousands of years. These changes are very likely a consequence of the very slow temperature drop that results from insolation changes. The amplify the cooling as expected from the basic physics of the greenhouse effect. But these changes are pretty small (i.e. changes within the major glacial-interglacial transitions). There the sorts of changes occurring over thousands of years that we are now seeing in 4-5 (10 ppm) or 8-10 (20 ppm) years at the current rate of expelling massive amounts of greenhouse gases into the atmosphere. So the Earth is warming at a rate that massively exceeds the very slow temperature changes due to the very, very slow Milankovitch cycles. During ice age cycles insolation changes dominated temperature changes with warming effects resulting in water vapour, CO2 and albedo feedbacks. Now during an extraordinarily miniscule time period in relation to the vast millenia of the ice age transitions, a rapid increase in temperature is occurring during a period of relatively constant insolation as a result of a massive hiking upwards of the atmospheric greenhouse gas concentration (with water vapour and albedo feedbacks as we can measure in the real world). It ain't rocket science Dan! And I'm afraid that blanket dismissal of scientific research that doesn't accord with your agenda, is taking conspiracy theorising too far!
130631. Mizimi at 06:30 AM on 6 December 2008
        Water vapor is the most powerful greenhouse gas
        The article concerns itself with radiative forcing and positive feedback and does not address basics.... The mass of CO2 in the atmosphere is around 3x 10E15 kg. The mass of WV is around 12.7 x 10E15 kg. The specific heat of CO2 @ 275K is 0.819kj/kg The specific heat of water @ 275K is around 4.2kj/kg Simplistically ( I can see the objections coming!) the heat content increase for a 1C temp increase is thus: CO2: 3x10E15 x 0.819 x 1 = 2.45 x 10E15 kj Water: 12.7 x 10E15 x 4.2 x 1 = 53.3 x 10E15 kj IE: the heat content available from wv is 22 x greater than CO2 disregarding any IR effect.
130632. Mizimi at 05:54 AM on 6 December 2008
        Latest satellite data on Greenland mass change
        It would be interesting to see the graph enlarged and extended back beyond the Gakkel ridge event in 1999, and a comparison with NA current flow and temps.
130633. Mizimi at 05:18 AM on 6 December 2008
        It hasn't warmed since 1998
        Interesting that only GISS still indicates a +ve trend whilst the other three show negative. roughly a +1C for GISS and -0.5C for the rest.
130634. Mizimi at 04:49 AM on 6 December 2008
        Can animals and plants adapt to global warming?
        Ps: Chris; I am not 'propagandising' against the science that 'might' find a solution to this problem. I am unconvinced that the 'problem' exists in the magnitude that is being proposed, especially since the 'science' is currently incapable of modelling what is going on to a reasonable degree of accuracy. In addition, the GMT ( which is actually a mathematical artefact and does not exist) 'record' indicates a rise of less than 2C by the end of this century. Hardly enough to cause panic attacks. Not only that, but I am skeptical that a)the root of the problem is just CO2 from fossil fuels and b)that even if it was, the chances of getting global action to reduce FF usage are pretty slim ( politicians being what they are). We already have countries pulling out of or ignoring agreements to reduce emissions ( The US, Canada, Australia to name but three, one of which is the biggest consumer...guess which) so either they don't care OR they know something we don't.
130635. Dan Pangburn at 12:26 PM on 5 December 2008
        Models are unreliable
        In post #68 Chris says “What quiet sun?” There are several agencies that report on solar activity that Chris could have accessed to find out. NOAA has revised several times their predictions of the magnitude and delay of the start of cycle 24. An animated display of the revisions can be viewed at http://wattsupwiththat.com/2008/10/05/nasa-moves-the-goalposts-on-solar-cycle-24-again/ . A day-by-day report of solar activity is available at http://www.dxlc.com/solar/ and http://www.swpc.noaa.gov/forecast.html. Numerical monthly sunspot averages since 1749 are at ftp://ftp.ngdc.noaa.gov/STP/SOLAR_DATA/SUNSPOT_NUMBERS/MONTHLY. As can be observed, the sun remains quiet, even for a solar minimum. The assertion that all temperature trend direction changes are brought about by Milankovitch cycles is rejected by history and logic. The longest Milankovitch cycle is about 100,000 years and has been associated with the glacial/interglacial cycle. Most have determined that it accounts for about half of the glacial/interglacial climate change. The shortest and much weaker 23,000 year Milankovitch cycle explains only about 10% of the variance (http://www.physics.ohio-state.edu/~wilkins/energy/Companion/E16.7.pdf.xpdf) . There is no mechanism by which any Milankovitch cycle could cause the observed temperature trend changes that last only a few millenniums or so. Chris has finally (albeit inadvertently) conceded that average global temperature uptrends and downtrends take place irrespective of the atmospheric carbon dioxide level with the statement in post #78 “a temperature downtrend at high/highish atmospheric CO2 levels only means that the particular driver of the temperature trend at that particular time is variation in insolation”. Think about it. A temperature downtrend continuing for a millennium or so with the carbon dioxide level higher at any given temperature than it was during a prior uptrend. The Vostok data show repeatedly a temperature uptrend changing to a downtrend with the carbon dioxide level during the downtrend higher than it had been during the uptrend. The NOAA data are graphed at the Middlebury web site given at post #41 or at http://www.roperld.com/science/CO2_Temp.pdf . No amount of spin or deception can alter that this proves that significant net positive feedback does not exist. Without the imposition of significant net positive feedback by the GCM users, the GCMs do not predict significant global warming. The many references that Chris likes to list are evidence of the group-think mentality that permeates the climate scientist community who benefit from dire predictions.
130636. Mizimi at 06:22 AM on 5 December 2008
        Can animals and plants adapt to global warming?
        Chris: Whether an extinction of a species is 'good' or 'bad' really depends on whether it's you or not, in other words, on your personal perspective. From a world view, the best thing might just be the extinction of Homo Sapiens Civilis!
130637. Mizimi at 05:57 AM on 5 December 2008
        What does CO2 lagging temperature mean?
        Philippe; In general I agree with what you are saying, but life started with very low biodiversity and until cyanobacteria started putting O2 into the atmosphere remained so. Since then, as Chris has adequately pointed out, various catastrophes have severely affected life in terms of diversity and quantity. Curiously,most of the life forms on earth seem hell-bent on overwhelming anything else ( particularly the smaller varieties) regardless of the consequencies? And you final comment is in agreement with my view that life adapts to fill any and all possible vacuums, so that loss of one species is an opportunity for another to take over that niche.
130638. paledriver at 00:59 AM on 5 December 2008
        There is no consensus
        #83. Yes that claim WAS made..."The American Physical Society, an organization representing nearly 50,000 physicists, has reversed its stance on climate change and is now proclaiming that many of its members disbelieve in human-induced global warming. " from Daily Tech.. so you got it wrong, again. and Mizimi, scientists have come to a consensus BECAUSE of the haed, irrefutable facts. and it's a growing consensus because of there continues to be more hard, irrefutable evidence uncovered. meanwhile, the other side consists mostly of former big tobacco schills who once told us there is no science to link smoking with lung cancer. remember that when you're picking your team.
130639. Mizimi at 06:02 AM on 4 December 2008
        Water vapor is the most powerful greenhouse gas
        Some figures from the World Water Council on evaporation from human sources (not abstraction which is much much higher) 1940 1950 1960 1970 1980 1990 2000 50...80..155..245.. 285..320..515 figures in cubic k's and exclude agriculture and domestic/municipal usage. Including these quadruples the figures. It is clear from the data that AWV has been steadily increasing since 1940 and thus the average global atmospheric water content will have risen since the atmosphere is not saturated. This addition occurs at low altitudes...precisely where one expects the warming effect of GG's to be the greatest.
130640. HealthySkeptic at 15:01 PM on 3 December 2008
        What 1970s science said about global cooling
        Re #17 That's nonsense of course. To critically question scientific evidence is not the same as denying it. It's part of the scientific method. However;- To deny a scientific fact is indeed undeniably stupid. To deny an unproven hypothesis is healthy skepticism. Let me know when AGW becomes a scientific fact.
130641. HealthySkeptic at 14:30 PM on 3 December 2008
        Global warming stopped in 1981... no, wait! 1991!
        Re #14 That's rubbish of course. What has that load of "schoolboy pseudo-psychoanalysis" have to do with "atmospheric, ocean and radiative physics"? -)
130642. HealthySkeptic at 14:09 PM on 3 December 2008
        The Mystery of the Vanishing Ocean Heat
        Chris, Get down off your high horse for a minute and calm down a bit. Wildly accusing people of having "creepy agendas" is in itself more than a bit creepy. The source you ask about is Dr. Nils-Axel Mörner. Specifically, comments he made in an interview which appeared in Executive Intelligence Review, June 22, 2007 An abridged version can be found here;- http://www.ourcivilisation.com/aginatur/sealevel.htm No doubt you will denegrate the poor man severly, as you seem to do with any researchers who disagree with your AGW paradigm. Yet, it still seems strange that if there is such a supposed “scientific consensus” on AGW that so many prominent scientists (especially those in directly-related fields of research) are having second thoughts. Perhaps it's the early signs of a forthcoming paradigm shift. ;)
130643. HealthySkeptic at 13:03 PM on 3 December 2008
        Misinterpreting a retraction of rising sea level predictions
        Re #16, Chris, Despite a very verbose reply in refering to #14, you totally ignored the point of my post, which was in direct response to John's claim that; "They (Fawcett and Jones) find the linear trend over 1998 to 2007 is a warming trend in all three data-sets." My point was that, based on the data sets presented in figure 2 above, the linear trends only appear to trend very slightly upward because of the skewing effect of the two lowest points in 1999 & 2000. There is therefore no credible warming trend in the data presented at all.
130644. chris at 09:57 AM on 3 December 2008
        Global warming stopped in 1998, 1995, 2002, 2007, 2010, ????
        Yes there's no doubt that the effects of the solar cycle are "overshadowed" by internal variations in the climate system. After all the peak to trough surface temperature variation between the solar cycle max and min is around 0.1 (maybe as much as 0.18) oC. Since year on year variation in the Earth's temperature anomaly can easily be 0.1 oC, the solar cycle doesn't really show up in the surface temperature record without efforts to deconvolute this. In general we expect the sun to contribute a little cooling during the solar minimum and a little warming (supplementing greenhouse gas warming) around the solar max. But just like the damped solar cycle contribution to the Earth's surface temperature, so the seasonal temperature variation is damped. For example if, rather than a seasonal drop in insolation where you live, the sun changed its output to give a constant insolation corrsponding to the cold season insolation, the water in the sea where you live would get a whole lot colder than 17 oC. But it would take a while for this new horribly cold temperature to settle at a new chilly equilibrium temperature.....
130645. chris at 09:41 AM on 3 December 2008
        It's the sun
        Not really Mizimi. The chemistry performed by living organisms is catalyzed by enzymes. Enzymes can be exquisitively sensitive to the chemical nature of their substrates, able to distinguish between stereoisomers (e.g. L- or D-amino acids) and showing rather significant preferences in relation to different isotopes of atoms such as 1H/2H; 12C/13C; 16O/18O and so on. The deposition of carbonates, for example, is thermodynamically controlled by the solubility properties of the salts which are very little affected by isotopic composition (12CO3-- cf 13CO3--). That's not to say that physical process don't result in some useful "fractionation" of molecules according to their isotopic composition. For example during cold periods, snow and rain from evaporated water tends to be very, very marginally enriched in 16OH2 since it takes a tiny bit more thermal energy to evaporate an 18OH2 molecule cf a 16OH2 one, and this can be used to determine paleotemperatures in ice cores, for example. However the fractionation of 12C over 13C by photosynthesising organisms is much larger.... We don't expect to see a measurable difference in 12C vs 13C in sea water except to the extent that the exchange of aqueous CO2 [CO2(aq) <--->H2CO3] and atmospheric CO2 results in a tendency for the oceanic CO2 to equilibrate with the continually-less-depleted 12C in the atmosphere that results from the return of long, long-sequestered 13-C-depleted carbon back into the atmosphere from burning massive amounts of fossil fuels.
130646. chris at 09:17 AM on 3 December 2008
        Human CO2 is a tiny % of CO2 emissions
        Not really Mizimi... Our understanding of the natural world is not defined by one individual's ignorance! If you don't know very much about a topic why not make an effort to inform yourself befoe sounding off? Try googling "dynamic equilibrium". Far from being an "oxymoron" it's a fundamental descriptor of phenomena that involve the summation of a number of (opposing) processes whose net effect constitutes a balance to an extent that is further definable by the amplitude of variation around the equilibrium position. When applied to reversible chemical reactions the variation around the equilibrium (concentration of reactants and products, for example) can be small small. When applied to Earth processes it can be somewhat larger.. ...it would be foolish to "invent a new word" for such a well-characterized phenomenon as "dynamic equilibrium". The temperature in a room that results from the opposing forces of heat loss and heat input controlled by a thermostat is an example of a "dynamic equilibrium". If one needed further description of the nature of the fluctuations around the equilibrium one could explore/measure these. Likewise with the Earth's atmopheric CO2 concentration. For millions of years the earth's atmospheric CO2 concentration has been in dynamic equilibrium between the forces of volcanic influx into the atmosphere and the efflux from weathering and carbonate "fixing" (supplemented during the last couple of million of years with glacial cycles that temporarily perturb the equilibrium CO2 concentration downwards during glacial periods). In other worlds, since the atmospheric CO2 concentrations haven't varied very much during this period as far as we can tell (apart from the ice age excursions), the evidence indicates that the atmospheric CO2 levels have been in "dynamic equilibrium" (until recently, when they've started progressing upweards at a very very fast rate). Incidentally your misinformed request for semantic rigour on the subject of equilibria is rather out of keeping with your craven acceptance of the most ludicrous and blatant tosh on plaeotemperature data or pre-present atmospheric CO2 data, and so on. You need to come to some decision about where your "standards" lie science/evidence-wise, and then apply these across the board!
130647. chris at 08:27 AM on 3 December 2008
        Temp record is unreliable
        We're not talking about modeling Mizimi. We're talking about measuring.
130648. Mizimi at 23:08 PM on 2 December 2008
        It's the sun
        Question: plants show a preference for C12 - true. But plants only have chemistry to work with ( not nuclear processes) so how do they manage that? And if they do it solely by chemistry then it follows other chemical processes can do it too.?? Oceanic plant life also prefers C12, so we should see the amount of C13 dissolved in sea water increase in respect of C12....is this the case??
130649. Arkadiusz Semczyszak at 21:43 PM on 2 December 2008
        It's ozone
        „while temperature trends continue upwards” - I don’t see it. And I looking in: the 1996-2008 period ( see for example http://wattsupwiththat.com/2008/03/11/to-tell-the-truth-will-the-real-global-average-temperature-trend-please-rise-part1/)) GISS , HadCRUT, UAH_MSU and RSS_MSU - cumulative seasonal differences temperature. The trends is reverse, not upwards, but same decreased or = 0, ± as exactly the ozone trend. All arguments for “It's the ozone…” are on: http://omsriram.com/GlobalWarming.htm. About UV radiation on the Earth surface, decide a ozone concentration with lover stratosphere, so temperature in this layer (http://www.atmosphere.mpg.de/media/archive/1385.jpg - it’s same different than above-mentioned Figure).
130650. Patrick 027 at 15:18 PM on 2 December 2008
        Arctic sea ice melt - natural or man-made?
        "Thus it makes some sense that a 'gradient wind balance',"..."total effective local f value (f_loc, see Bluestein p. 190) equal to f + 2*V/R"... Actually it is some aspect of the gradient wind balance, and of course, to make complete sense of that requires some other math...

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