Note: This was a poster, and adopted into a blog post by the author, Ned Nikolov, specifically for WUWT. My thanks to him for the extra effort in converting the poster to a more blog friendly format. – Anthony
Expanding the Concept of Atmospheric Greenhouse Effect Using Thermodynamic Principles: Implications for Predicting Future Climate Change
Ned Nikolov, Ph.D. & Karl Zeller, Ph.D.
USFS Rocky Mountain Research Station, Fort Collins CO, USA
Emails: ntconsulting@comcast.net kzeller@colostate.edu
Poster presented at the Open Science Conference of the World Climate Research Program,
24 October 2011, Denver CO, USA
http://www.wcrp-climate.org/conference2011/posters/C7/C7_Nikolov_M15A.pdf
Abstract
We present results from a new critical review of the atmospheric Greenhouse (GH) concept. Three main problems are identified with the current GH theory. It is demonstrated that thermodynamic principles based on the Gas Law need be invoked to fully explain the Natural Greenhouse Effect. We show via a novel analysis of planetary climates in the solar system that the physical nature of the so-called GH effect is a Pressure-induced Thermal Enhancement (PTE), which is independent of the atmospheric chemical composition. This finding leads to a new and very different paradigm of climate controls. Results from our research are combined with those from other studies to propose a new Unified Theory of Climate, which explains a number of phenomena that the current theory fails to explain. Implications of the new paradigm for predicting future climate trends are briefly discussed.
1. Introduction
Recent studies revealed that Global Climate Models (GCMs) have significantly overestimated the Planet’s warming since 1979 failing to predict the observed halt of global temperature rise over the past 13 years. (e.g. McKitrick et al. 2010). No consensus currently exists as to why the warming trend ceased in 1998 despite a continued increase in atmospheric CO2 concentration. Moreover, the CO2-temperature relationship shows large inconsistencies across time scales. In addition, GCM projections heavily depend on positive feedbacks, while satellite observations indicate that the climate system is likely governed by strong negative feedbacks (Lindzen & Choi 2009; Spencer & Braswell 2010). At the same time, there is a mounting political pressure for Cap-and-Trade legislation and a global carbon tax, while scientists and entrepreneurs propose geo-engineering solutions to cool the Planet that involve large-scale physical manipulation of the upper atmosphere. This unsettling situation calls for a thorough reexamination of the present climate-change paradigm; hence the reason for this study.
2. The Greenhouse Effect: Reexamining the Basics
Figure 1. The Atmospheric Greenhouse Effect as taught at universities around the World (diagram from the website of the Penn State University Department of Meteorology).
According to the current theory, the Greenhouse Effect (GHE) is a radiative phenomenon caused by heat-trapping gases in the atmosphere such as CO2 and water vapor that are assumed to reduce the rate of surface infrared cooling to Space by absorbing the outgoing long-wave (LW) emission and re-radiating part of it back, thus increasing the total energy flux toward the surface. This is thought to boost the Earth’s temperature by 18K – 33K compared to a gray body with no absorbent atmosphere such as the Moon; hence making our Planet habitable. Figure 1 illustrates this concept using a simple two-layer system known as the Idealized Greenhouse Model (IGM). In this popular example, S is the top-of-the atmosphere (TOA) solar irradiance (W m-2), A is the Earth shortwave albedo, Ts is the surface temperature (K), Te is the Earth’s effective emission temperature (K) often equated with the mean temperature of middle troposphere, ϵ is emissivity, and σ is the Stefan-Boltzmann (S-B) constant.
2.1. Main Issues with the Current GHE Concept:
A) Magnitude of the Natural Greenhouse Effect. GHE is often quantified as a difference between the actual mean global surface temperature (Ts = 287.6K) and the planet’s average gray-body (no-atmosphere) temperature (Tgb), i.e. GHE = Ts – Tgb. In the current theory, Tgb is equated with the effective emission temperature (Te) calculated straight from the S-B Law using Eq. (1):
where αp is the planetary albedo of Earth (≈0.3). However, this is conceptually incorrect! Due to Hölder’s inequality between non-linear integrals (Kuptsov 2001), Te is not physically compatible with a measurable true mean temperature of an airless planet. To be correct, Tgb must be computed via proper spherical integration of the planetary temperature field. This means calculating the temperature at every point on the Earth sphere first by taking the 4th root from the S-B relationship and then averaging the resulting temperature field across the planet surface, i.e.
where αgb is the Earth’s albedo without atmosphere (≈0.125), μ is the cosine of incident solar angle at any point, and cs= 13.25e-5 is a small constant ensuring that Tgb = 2.72K (the temperature of deep Space) when So = 0. Equation (2) assumes a spatially constant albedo (αgb), which is a reasonable approximation when trying to estimate an average planetary temperature.
Since in accordance with Hölder’s inequality Tgb ≪ Te (Tgb =154.3K ), GHE becomes much larger than presently estimated.
According to Eq. (2), our atmosphere boosts Earth’s surface temperature not by 18K—33K as currently assumed, but by 133K! This raises the question: Can a handful of trace gases which amount to less than 0.5% of atmospheric mass trap enough radiant heat to cause such a huge thermal enhancement at the surface? Thermodynamics tells us that this not possible.
B) Role of Convection. The conceptual model in Fig. 1 can be mathematically described by the following simultaneous Equations (3),
where νa is the atmospheric fraction of the total shortwave radiation absorption. Figure 2 depicts the solution to Eq. (3) for temperatures over a range of atmospheric emissivities (ϵ) assuming So = 1366 W m-2 and νa =0.326 (Trenberth et al. 2009). An increase in atmospheric emissivity does indeed cause a warming at the surface as stated by the current theory. However, Eq. (3) is physically incomplete, because it does not account for convection, which occurs simultaneously with radiative transfer. Adding a convective term to Eq. (3) (such as a sensible heat flux) yields the system:
where gbH is the aerodynamic conductance to turbulent heat exchange. Equation (4) dramatically alters the solution to Eq. (3) by collapsing the difference between Ts, Ta and Te and virtually erasing the GHE (Fig. 3). This is because convective cooling is many orders of magnitude more efficient that radiative cooling. These results do not change when using multi-layer models. In radiative transfer models, Ts increases with ϵ not as a result of heat trapping by greenhouse gases, but due to the lack of convective cooling, thus requiring a larger thermal gradient to export the necessary amount of heat. Modern GCMs do not solve simultaneously radiative transfer and convection. This decoupling of heat transports is the core reason for the projected surface warming by GCMs in response to rising atmospheric greenhouse-gas concentrations. Hence, the predicted CO2-driven global temperature change is a model artifact!
Figure 2. Solution to the two-layer model in Eq. (3) for Ts and Ta as a function of atmospheric emissivity assuming a non-convective atmosphere. Also shown is the predicted down-welling LW flux(Ld). Note that Ld ≤ 239 W m-2.
Figure 3. Solution to the two-layer model in Eq. (4) for Ts and Ta as a function of atmospheric emissivity assuming a convective atmosphere (gbH = 0.075 m/s). Also shown is the predicted down-welling LW flux (Ld). Note that Ld ≤ 239 W m-2.
Figure 4. According to observations, the Earth-Atmosphere System absorbs on average a net solar flux of 239 W m-2, while the lower troposphere alone emits 343 W m-2 thermal radiation toward the surface.
C) Extra Kinetic Energy in the Troposphere.
Observations show that the lower troposphere emits 44% more radiation toward the surface than the total solar flux absorbed by the entire Earth-Atmosphere System (Pavlakis et al. 2003) (Fig. 4). Radiative transfer alone cannot explain this effect (e.g. Figs. 2 & 3) given the negligible heat storage capacity of air, no matter how detailed the model is. Thus, empirical evidence indicates that the lower atmosphere contains more kinetic energy than provided by the Sun. Understanding the origin of this extra energy is a key to the GHE.
3. The Atmospheric Thermal Enhancement
Previous studies have noted that the term Greenhouse Effect is a misnomer when applied to the atmosphere, since real greenhouses retain heat through an entirely different mechanism compared to the free atmosphere, i.e. by physically trapping air mass and restricting convective heat exchange. Hence, we propose a new term instead, Near-surface Atmospheric Thermal Enhancement (ATE) defined as a non-dimensional ratio (NTE) of the planet actual mean surface air temperature (Ts, K) to the average temperature of a Standard Planetary Gray Body (SPGB) with no atmosphere (Tgb, K) receiving the same solar irradiance, i.e. NTE = Ts /Tgb. This new definition emphasizes the essence of GHE, which is the temperature boost at the surface due to the presence of an atmosphere. We employ Eq. (2) to estimate Tgb assuming an albedo αgb = 0.12 and a surface emissivity ϵ = 0.955 for the SPGB based on data for Moon, Mercury, and the Earth surface. Using So = 1362 W m-2 (Kopp & Lean 2011) in Eq. (2) yields Tgb = 154.3K and NTE = 287.6/154.3 = 1.863 for Earth. This prompts the question: What mechanism enables our atmosphere to boost the planet surface temperature some 86% above that of a SPGB? To answer it we turn on to the classical Thermodynamics.
3.1. Climate Implications of the Ideal Gas Law
The average thermodynamic state of a planet’s atmosphere can be accurately described by the Ideal Gas Law (IGL):
PV = nRT (5)
where P is pressure (Pa), V is the gas volume (m3), n is the gas amount (mole), R = 8.314 J K-1 mol-1is the universal gas constant, and T is the gas temperature (K). Equation (5) has three features that are chiefly important to our discussion: a) the product P×V defines the internal kinetic energy of a gas (measured in Jules) that produces its temperature; b) the linear relationship in Eq. (5) guarantees that a mean global temperature can be accurately estimated from planetary averages of surface pressure and air volume (or density). This is in stark contrast to the non-linear relationship between temperature and radiant fluxes (Eq. 1) governed by Hölder’s inequality of integrals; c) on a planetary scale, pressure in the lower troposphere is effectively independent of other variables in Eq. (5) and is only a function of gravity (g), total atmospheric mass (Mat), and the planet surface area (As), i.e. Ps = g Mat/As. Hence, the near-surface atmospheric dynamics can safely be assumed to be governed (over non-geological time scales) by nearly isobaric processes on average, i.e. operating under constant pressure. This isobaric nature of tropospheric thermodynamics implies that the average atmospheric volume varies in a fixed proportion to changes in the mean surface air temperature following the Charles/Gay-Lussac Law, i.e. Ts/V = const. This can be written in terms of the average air density ρ (kg m-3) as
ρTs = const. = Ps M / R (6)
where Ps is the mean surface air pressure (Pa) and M is the molecular mass of air (kg mol-1). Eq. (6) reveals an important characteristic of the average thermodynamic process at the surface, namely that a variation of global pressure due to either increase or decrease of total atmospheric mass will alter both temperature and atmospheric density. What is presently unknown is the differential effect of a global pressure change on each variable. We offer a solution to this in & 3.3. Equations (5) and (6) imply that pressure directly controls the kinetic energy and temperature of the atmosphere. Under equal solar insolation, a higher surface pressure (due to a larger atmospheric mass) would produce a warmer troposphere, while a lower pressure would result in a cooler troposphere. At the limit, a zero pressure (due to the complete absence of an atmosphere) would yield the planet’s gray-body temperature.
The thermal effect of pressure is vividly demonstrated on a cosmic scale by the process of star formation, where gravity-induced rise of gas pressure boosts the temperature of an interstellar cloud to the threshold of nuclear fusion. At a planetary level, the effect is manifest in Chinook winds, where adiabatically heated downslope airflow raises the local temperature by 20C-30C in a matter of hours. This leads to a logical question: Could air pressure be responsible for the observed thermal enhancement at the Earth surface presently known as a ‘Natural Greenhouse Effect’? To answer this we must analyze the relationship between NTEfactor and key atmospheric variables including pressure over a wide range of planetary climates. Fortunately, our solar system offers a suitable spectrum of celestial bodies for such analysis.
3.2. Interplanetary Data Set
We based our selection of celestial bodies for the ATE analysis on three criteria: 1) presence of a solid planetary surface with at least traces of atmosphere; 2) availability of reliable data on surface temperature, total pressure, atmospheric composition etc. preferably from direct measurements; and 3) representation of a wide range of atmospheric masses and compositions. This approach resulted in choosing of four planets – Mercury, Venus, Earth, and Mars, and four natural satellites – Moon of Earth, Europa of Jupiter, Titan of Saturn, and Triton of Neptune. Each celestial body was described by 14 parameters listed in Table 1.
For planets with tangible atmospheres, i.e. Venus, Earth and Mars, the temperatures calculated from IGL agreed rather well with observations. Note that, for extremely low pressures such as on Mercury and Moon, the Gas Law produces Ts ≈ 0.0. The SPGB temperatures for each celestial body were estimated from Eq. (2) using published data on solar irradiance and assuming αgb = 0.12 and ϵ = 0.955. For Mars, global means of surface temperature and air pressure were calculated from remote sensing data retrieved via the method of radio occultation by the Radio Science Team (RST) at Stanford University using observations by the Mars Global Surveyor (MGS) spacecraft from 1999 to 2005. Since the MGS RST analysis has a wide spatial coverage, the new means represent current average conditions on the Red Planet much more accurately than older data based on Viking’s spot observations from 1970s.
Table 1. Planetary data used to analyze the physical nature of the Atmospheric Near-Surface Thermal Enhancement (NTE). Information was gathered from multiple sources using cross-referencing. The bottom three rows of data were estimated in this study using equations discussed in the text.
3.3. Physical Nature of ATE / GHE
Our analysis of interplanetary data in Table 1 found no meaningful relationships between ATE (NTE) and variables such as total absorbed solar radiation by planets or the amount of greenhouse gases in their atmospheres. However, we discovered that NTE was strongly related to total surface pressure through a nearly perfect regression fit via the following nonlinear function:
where Ps is in Pa. Figure 5 displays Eq. (7) graphically. The tight relationship signals a causal effect of pressure on NTE, which is theoretically supported by the IGL (see & 3.1). Also, the Ps–NTE curve in Fig. 5 strikingly resembles the response of the temperature/potential temp. (T/θ) ratio to altitudinal changes of pressure described by the well-known Poisson formula derived from IGL (Fig. 6). Such a similarity in responses suggests that both NTE and θ embody the effect of pressure-controlled adiabatic heating on air, even though the two mechanisms are not identical. This leads to a fundamental conclusion that the ‘Natural Greenhouse Effect’ is in fact a Pressure-induced Thermal Enhancement (PTE) in nature.
NTE should not be confused with an actual energy, however, since it only defines the relative (fractional) increase of a planet’s surface temperature above that of a SPGB. Pressure by itself is not a source of energy! Instead, it enhances (amplifies) the energy supplied by an external source such as the Sun through density-dependent rates of molecular collision. This relative enhancement only manifests as an actual energy in the presence of external heating. Thus, Earth and Titan have similar NTE values, yet their absolute surface temperatures are very different due to vastly dissimilar solar insolation. While pressure (P) controls the magnitude of the enhancement factor, solar heating determines the average atmospheric volume (V), and the product P×V defines the total kinetic energy and temperature of the atmosphere. Therefore, for particular solar insolation, the NTE factor gives rise to extra kinetic energy in the lower atmosphere beyond the amount supplied by the Sun. This additional energy is responsible for keeping the Earth surface 133K warmer than it would be in the absence of atmosphere, and is the source for the observed 44% extra down-welling LW flux in the lower troposphere (see &2.1 C). Hence, the atmosphere does not act as a ‘blanket’ reducing the surface infrared cooling to space as maintained by the current GH theory, but is in and of itself a source of extra energy through pressure. This makes the GH effect a thermodynamic phenomenon, not a radiative one as presently assumed!
Equation (7) allows us to derive a simple yet robust formula for predicting a planet’s mean surface temperature as a function of only two variables – TOA solar irradiance and mean atmospheric surface pressure, i.e.
Figure 5. Atmospheric near-surface Thermal Enhancement (NTE) as a function of mean total surface pressure (Ps) for 8 celestial bodies listed in Table 1. See Eq. (7) for the exact mathematical formula.
Figure 6. Temperature/potential temperature ratio as a function of atmospheric pressure according to the Poisson formula based on the Gas Law (Po = 100 kPa.). Note the striking similarity in shape with the curve in Fig. 5.
where NTE(Ps) is defined by Eq. (7). Equation (8) almost completely explains the variation of Ts among analyzed celestial bodies, thus providing a needed function to parse the effect of a global pressure change on the dependent variables ρ and Tsin Eq. (6). Together Equations (6) and (8) imply that the chemical composition of an atmosphere affects average air density through the molecular mass of air, but has no impact on the mean surface temperature.
4. Implications of the new ATE Concept
The implications of the above findings are numerous and paradigm-altering. These are but a few examples:
Figure 7. Dynamics of global temperature and 12-month forward shifted cloud cover types from satellite observations. Cloud changes precede temperature variations by 6 to 24 months and appear to have been controlling the latter during the past 30 years (Nikolov & Zeller, manuscript).
A) Global surface temperature is independent of the down-welling LW flux known as greenhouse or back radiation, because both quantities derive from the same pool of atmospheric kinetic energy maintained by solar heating and air pressure. Variations in the downward LW flux (caused by an increase of tropospheric emissivity, for example) are completely counterbalanced (offset) by changes in the rate of surface convective cooling, for this is how the system conserves its internal energy.
B) Modifying chemical composition of the atmosphere cannot alter the system’s total kinetic energy, hence the size of ATE (GHE). This is supported by IGL and the fact that planets of vastly different atmospheric composition follow the same Ps–NTE relationship in Fig. 5. The lack of impact by the atmospheric composition on surface temperature is explained via the compensating effect of convective cooling on back-radiation discussed above.
C) Equation (8) suggests that the planet’s albedo is largely a product of climate rather than a driver of it. This is because the bulk of the albedo is a function of the kinetic energy supplied by the Sun and the atmospheric pressure. However, independent small changes in albedo are possible and do occur owning to 1%-3% secular variations in cloud cover, which are most likely driven by solar magnetic activity. These cloud-cover changes cause ±0.7C semi-periodic fluctuations in global temperature on a decadal to centennial time scale as indicated by recent satellite observations (see Fig. 7) and climate reconstructions for the past 10,000 years.
Figure 8. Dynamics of global surface temperature during the Cenozoic Era reconstructed from 18O proxies in marine sediments (Hansen et al. 2008).
Figure 9. Dynamics of mean surface atmospheric pressure during the Cenozoic Era reconstructed from the temperature record in Fig. 8 by inverting Eq. (8).
D) Large climatic shifts evident in the paleo-record such as the 16C directional cooling of the Globe during the past 51 million years (Fig. 8) can now be explained via changes in atmospheric mass and surface pressure caused by geologic variations in Earth’s tectonic activity. Thus, we hypothesize that the observed mega-cooling of Earth since the early Eocene was due to a 53% net loss of atmosphere to Space brought about by a reduction in mantle degasing as a result of a slowdown in continental drifts and ocean floor spreading. Figure 9 depicts reconstructed dynamics of the mean surface pressure for the past 65.5M years based on Eq. (8) and the temperature record in Fig. 8.
5. Unified Theory of Climate
The above findings can help rectify physical inconsistencies in the current GH concept and assist in the development of a Unified Theory of Climate (UTC) based on a deeper and more robust understanding of various climate forcings and the time scales of their operation. Figure 10 outlines a hierarchy of climate forcings as part of a proposed UTC that is consistent with results from our research as well as other studies published over the past 15 years. A proposed key new driver of climate is the variation of total atmospheric mass and surface pressure over geological time scales (i.e. tens of thousands to hundreds of millions of years). According to our new theory, the climate change over the past 100-300 years is due to variations of global cloud albedo that are not related to GHE/ATE. This is principally different from the present GH concept, which attempts to explain climate changes over a broad range of time scales (i.e. from decades to tens of millions of years) with the same forcing attributed to variations in atmospheric CO2 and other heat-absorbing trace gases (e.g. Lacis et al. 2010).
Earth’s climate is currently in one of the warmest periods of the Holocene (past 10K years). It is unlikely that the Planet will become any warmer over the next 100 years, because the cloud cover appears to have reached a minimum for the present levels of solar irradiance and atmospheric pressure, and the solar magnetic activity began declining, which may lead to more clouds and a higher planetary albedo. At this point, only a sizable increase of the total atmospheric mass can bring about a significant and sustained warming. However, human-induced gaseous emissions are extremely unlikely to produce such a mass increase.
Figure 10. Global climate forcings and their time scales of operation according to the hereto proposed Unified Theory of Climate (UTC). Arrows indicate process interactions.
6. References
Kopp, G. and J. L. Lean (2011). A new, lower value of total solar irradiance: Evidence and climate significance, Geophys. Res. Lett., 38, L01706, doi:10.1029/2010GL045777.
Kuptsov, L. P. (2001) Hölder inequality, in Hazewinkel, Michiel, Encyclopedia of Mathematics, Springer, ISBN 978-1556080104.
Lacis, A. A., G. A. Schmidt, D. Rind, and R. A. Ruedy (2010). Atmospheric CO2: Principal control knob governing earth’s temperature. Science 330:356-359.
Lindzen, R. S. and Y.-S. Choi (2009). On the determination of climate feedbacks from ERBE data. Geophys. Res. Lett., 36, L16705, doi:10.1029/2009GL039628.
McKitrick, R. R. et al. (2010). Panel and Multivariate Methods for Tests of Trend Equivalence in Climate Data Series. Atmospheric Science Letters, Vol. 11, Issue 4, pages 270–277.
Nikolov, N and K. F. Zeller (manuscript). Observational evidence for the role of planetary cloud-cover dynamics as the dominant forcing of global temperature changes since 1982.
Pavlakis, K. G., D. Hatzidimitriou, C. Matsoukas, E. Drakakis, N. Hatzianastassiou, and I. Vardavas (2003). Ten-year global distribution of down-welling long-wave radiation. Atmos. Chem. Phys. Discuss., 3, 5099-5137.
Spencer, R. W. and W. D. Braswell (2010). On the diagnosis of radiative feedback in the presence of unknown radiative forcing, J. Geophys. Res., 115, D16109, doi:10.1029/2009JD013371
Trenberth, K.E., J.T. Fasullo, and J. Kiehl (2009). Earth’s global energy budget. BAMS, March:311-323
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This post is also available as a PDF document here:
Unified_Theory_Of_Climate_Poster_Nikolov_Zeller
UPDATE: This thread is closed – see the newest one “A matter of some Gravity” where the discussion continues.
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I’m not a scientist: I’m a science fiction writer. However, science fiction MUST be based on known science, or it becomes fantasy (some exceptions are allowed, such as FTL travel, etc.). This article provides much for me to ponder, but at the same time, answers a bunch of questions I’ve had in my mind about a lot of things. If Nobel Prizes were awarded for ideas, these two scientists deserve one. The only flaw I find in the article is the failure to include the discussion of gravity as a factor in gas pressure. I look forward to the continuing discussion.
This article gives us much to ponder in looking for exosolar planets that may contain life as we know it. We need a planet in the right location, one with an atmosphere and water, and one thing missing from the above equations: a moon. We can see what happens when a planet doesn’t have a moon of the proper dimension by looking at Venus. Venus could be terraformed simply by moving Ceres into a stable orbit about 185,000 miles above its surface, and adding a few thousand icy comets to supply water. Mars would be harder: you would have to add a decent-sized moon, move the smaller ones further out from the surface, and add planetary mass (both water and minerals) until the mass was sufficient to hold a decent atmosphere. Both are feasible, at least in an engineering sense.
Lots of silliness here about star formation: stars are formed when the density of the gasses in a given location reach sufficient MASS to condense enough to become hot enough to begin stellar fusion, and also great enough to counter the outward pressure such fusion would cause. Gas heat and pressure, caused by gravitational compression, explain star formation. It also accounts for the fact that Jupiter and Saturn are warmer than they would otherwise be. I’ve read somewhere, can’t remember where now, that if Jupiter were about six times larger, it would be a brown dwarf instead of a planet. I can’t vouch for the veracity of that statement, but it’s plausible.
For all its supposed flaws, I find this theory far superior to the current hypothesis of catastrophic anthropogenic global warming. I also feel this will be the final nail in the coffin of that ridiculous hypothesis.
I commended Nikolov and Zeller when I first read their paper. I also commend Anthony for posting it for wider dissemination and discussion.
I don’t want to detract from these efforts, however, I did draw Nikolov’s attention to the work of Hans Jelbring:
http://ruby.fgcu.edu/courses/twimberley/EnviroPhilo/FunctionOfMass.pdf
I don’t know Hans’ situation as he disappeared off the blogs a little while ago. Nikilov was going to contact him.
I also suggest people look at Jelbring’s 1998 doctoral thesis at Stockholm University titled “Wind Controlled Climate”. Wind is the most overlooked variable in climate studies yet critical in rates of evaporation, transpiration and heat transfer vertically (convection) and horizontally (advection). Consider the change in global dynamics created by a wind speed increase or decrease of 1 kph.
This analysis seems to assume the volume of the atmosphere stays constant and I’m pretty sure it doesn’t.
The back radiation measured at 2 metres height, originates millimetres to a few metres above the instrument.
The molecules at this level are colliding with each other 6.7 billion times per second, many times faster than the average relaxation/emission timeline for GHGs.
The backradiation is coming from all the gaseous molecules since the emission spectrum for backradiation is very close to a blackbody spectrum (at the temperature of the 2 metre air) – Not the signature of CO2 or H2O high up in the troposphere as so many people assume.
When it is not cloudy, (35% of the time), there is small loss in the atmospheric window region, but when clouds are present (65% of the time), it is a perfect blackbody spectrum.
gas laws don’t deal with phase change, either.
water gas will rise without any convection, too, until it stops being a gas. (while carrying the family joules that no other molecules can manage)
@ur momisugly Wayne
Some random ideas:
First, remember that an average temperature, in the thermodynamic sense, is calculated by integrating T(t) from t1 to t2 and dividing by t2-t1. Adding the daily high and low temperature together and dividing by two will only give you the same answer on accident.
Now, as to how one would observe a trend in the second kind of average. The oceans go through hot and cold surface cycles, and big changes to humidity actually affect the molar density of surface air in a substantial way. Second, cloud cover causes vertical winds which decrease surface pressure and increase it at higher altitudes.
Let’s assume we’ve taken enough data such that ocean trends and albedo trends have smoothed out to no net effect. If we had a series of several billion identical working thermometers evenly spread accross the globe and they took constant measurements of T and computed the average with calculus then I don’t know if one could observe much of a trend in surface temperature. But if you randomly placed a much smaller number of non-identical (and to some extent non-functioning) thermometers and calculated the average temperature incorrectly then why wouldn’t one observe some random pattern?
Kevin Kilty: “It isn’t the gravity induced rise of gas pressure, but rather the work done by gravity versus heat lost to radiation that increases temperature in star formation.”
Looks to me like you are simply handwaving here. What is the work that is done by gravity? It is an increase in pressure. The increase in pressure results in an increase in temperature.
Kevin: “John Wilkes Booth rightly points out that PV is not internal kinetic energy. ”
N&Z recognize this and address it. If you want to agree with Booth you need to understand that he is not speaking to anything that N&Z are not aware of and have not addressed.
Kevin: “You and I agree that the discussion and application of the gas law in this contribution is a mess.”
It looks to me like the only mess is your understanding of what they are talking about. It also looks to me like they are perfectly aware of your objection and have dealt with it. An increase in gas pressure means that the molecules are more closely packed together. When they are more closely packed together their temperature is more effected by solar radiation passing through. Simply think of a transparent cube in space that is empty and one that has gas in it. Now pass solar radiation through each cube and guess what the results will be. The cube with gas in it is able to absorb much more energy from the sun than the one with no gas in it. And it will have a higher internal temperature than the one with no gas in it by the time it reaches radiative equilibrium. Booth’s experiment of pumping up a cylinder has no relevance to the issue that K&Z are talking about.
Bengt Abelsson says:
December 29, 2011 at 11:12 am
“JWBs home compressor tank is probably following the gas laws, a 15 K drop in temperature gives a 5 % drop in pressure that You won´t notice. (and a very very small drop in volume).”
PV = rNT
Sure. (V)olume is constant if we pretend the tank is made of something that doesn’t exhibit shrinkage when it’s cold. (N)umber of moles of air in the tank is also constant if we pretend it’s completely air tight. (T)emperature is changing becaue there is no internal source of heat to maintain the tank temperature above ambient air temperature. (P)ressure will change to follow externally driven temperature change.
Any questions so far?
On a planet (P)ressure is determined by composition of the air, (N)umber of moles in the vertical column, and a new term g for acceleration of (g)ravity. Note that pressure does not vary with (T)emperature in the planetary atomosphere.
Still with me?
If pressure doesn’t vary with temperature then temperature doesn’t vary with pressure.
OMG!
QED.
You are basically re-stating my first comment in this thread, — we assume that atmospheric mass is more or less constant over geological time. But is that is a valid assumption?
You don’t necessarily need to blow off a large amount of the atmosphere to change atmospheric mass, although that would certainly do it.
You can also remove atmospheric mass (and incidentally increase the solid earth mass) through either condensation, or freezing out a component of the atmosphere as on Mars where CO2 is pulled out of the gaseous atmosphere and frozen out in the polar caps.
You could also chemically bond and tie up portions of the atmosphere through chemical reactions and conversion to solid or liquid state. For example O2 oxidizing iron in the early earth sucked huge amounts of free oxygen out of the atmosphere. Plants converting CO2 and water to biomass (coal, oil plant residue like peat)
Or you can dissolve portions of the gaseous atmosphere in the oceans as happens with CO2.
You can also increase the atmospheric mass if the earth were to pass through a zone of interstellar space where it ingested huge quantities of dust that contained volatile compounds that would be gasified to a non-condensable gas form, during re-entry. Such as sulfur that was converted to sulfur dioxide (which eventually would be stripped out of the atmosphere by reaction to water), or ammonia and methane ices etc.
Is there a reasonable physical proxy that could be used to build an ice core record of ancient barometric pressures or some chemical marker in some biological process that changes at pressures near normal atmospheric pressure?
Larry
Bill Iillis: what is the view angle of the IR detector?
Mike: “The only flaw I find in the article is the failure to include the discussion of gravity as a factor in gas pressure.”
Mike, you can compress gas with gravity or you can compress it in a container. How it got to be compressed makes no difference regarding how the gas reacts to solar radiation passing through it. All that matters is that it has a certain pressure, not how it got that pressure. In looking at conditions on other planets, both the amount of gas and the gravity pulling on that gas effect the pressure. But again, how it got the pressure it has doesn’t matter. It only matters what the pressure is.
wayne says:
December 29, 2011 at 7:54 am
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I accept that Earth’s atmosphere is not in a confined cylinder and that there can be volumerric changes. That siad, gravity is a containment field.
However, we see pressure changes on a daily basis. Low pressure areas are places where there is less mass of atmosphere above and high pressure areas are places where there is a greater mass of atmosphere above. The atmosphere is in constant flux. for example, preceding a chinook wind there are pressure changes ditto huricanes, tornados and the like.
Even where there is only a volumetric change, work is being done and an inevitable by product of this work is heat.
I do not know whether the net effect of all these changes (including the passage of the diurnal bulge) is enough to maintain (in broad terms) the temperature of the atmosphere, but certainly some heat is being put into the atmosphere as a consequence of the work done, That must be an inescapable fact but its sufficiency is entirely a different matter.
Yes, I think this is an interesting thread, and has been very useful. This is what WUWT is all about, isn’t it? Letting people comment and ask questions and argue and learn.
This theory cannot explain the thermosphere at all. The thermosphere has higher temperature than anything on earth but volcanic eruptions. The sun’s corona could find any explanation in here at all either. And I’m glad you brought this up. It helps reinforce the truth of this matter. Temperature is the result of energy balance, We need work+heat considerations to arrive at an energy balance. The gas laws provide nothing regarding energy balance. They are equations of state. This is why figures 5,6 have little to do with 7,8.
Bengt Abelsson, Urederra.
Yes, but Wikipedia says that the range is 90 – 700 K.
So says NASA’s fact sheet (590-725 K, sun-ward side), but this theory says the mean temp has to be 248K at Mercury, and it is not.
Same thing happens to the Moon (253K, and not 154K). It’s easy. They have a new way to calculate the effective temperature of a planet (everything is based on that). And for planets without atmosphere, they choose the calculated temp as the “observed” one, and everything fits. That’s where the problem with the -133K comes. Looks funny.
Bill: “The Earth should have been a frozen snowball until about 500 million years. ”
Bill, it seems to me that the earth, as it gathered mass and compressed, was it’s own heat source.
If I remember right, it’s crust was, at one time, molten. It has been loosing it’s own energy of formation for most of its life.
Ryan says:
December 29, 2011 at 2:27 pm
This analysis seems to assume the volume of the atmosphere stays constant and I’m pretty sure it doesn’t.
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There’s a winner!! And, because the volume doesn’t, neither does the mole mass. Many people here get so caught up in the P vs T thing they miss the other variables. The fact is, the P and the T don’t vary very much. At least they haven’t in the last few thousand years. We’re talking about 0.5K here. Another thing to note, the IGL doesn’t ascribe causation. It is simply an equation. For some reason, this causes people to miss the forest because of all the trees infront of it. Pressure isn’t a determination on its own, and neither is temperature. They are functions of other things such as work. But, work isn’t a thing in and of itself either.
How I would use the IGL would be as a check to see if my other formulas and thoughts were correct. I don’t believe we have to precision to know the exact volume or mole mass (or temps for that matter) of our entire atmosphere. So, we’re not going to be able to detect a change of a few hundredths of a degree C or F using the IGL. But, its a law, so other thoughts concerning our atmospheric temps must conform to the IGL.
Joel Shore (December 29, 2011 at 8:53 am):
I believe you’ve misread the article. The authors do not deny the existence of the back radiation. However they assert that, at Earth’s surface, a change in the intensity of the back radiation is matched by a change of the free convective heat transfer. Consequently, changes in the intensity of the back radiation at Earth’s surface lack effects upon the transfer of heat from Earth’s surface.
Bill illis: I have thought on your experimental observations. There is now no doubt in my mind that the Trenberthian view of back radiation is plain wrong. No climate model can predict climate. CO2-AGW has been vastly over-estimated. basically, The modelling work has to be restarted with proper physics.
Tilo Reber says:
December 29, 2011 at 2:53 pm
Kevin Kilty: “It isn’t the gravity induced rise of gas pressure, but rather the work done by gravity versus heat lost to radiation that increases temperature in star formation.”
Looks to me like you are simply handwaving here. What is the work that is done by gravity? It is an increase in pressure. The increase in pressure results in an increase in temperature.
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Not really. The increase in temperature happens because the same amount of gas was forced into a smaller volume against its will. That takes work to accomplish just like it takes work to force a cat into a pet carrier against its will – both you and the cat will get warmer as the work is performed. Whether it’s a compressor or gravity or cat stuffing it is this work being accomplished which heats up the [ahem] working fluid. When the work is finished so is the rise in temperature and the temperature of the gas is then determined by something else. That something else in a star is nuclear fusion. If it fails to reach fusion temperature/pressure it will get colder and colder once gravity and gas pressure reaches equilibrium and volume stops shrinking – unless something external changes like more mass falling into it.
This explication goes in the direction I have been thinking, but I don’t have the tools or time to pursue. It just makes sense. In 100 years, we may be able to add a few extra-solar planets to that graph.
Let me respond to a few of your comments.
The feeling of cold at altitude is due to the lack of pressure. The feeling of cold is because the temperature is low, but also human beings have skin sensors for heat flow, and so they tend to feel cold when heat transfer out of the body is high. Heat transfer from the human body is largely through radiation, convection, and evaporation. At high elevation radiation and evaporation transfer out of the body are rapid.
The reason there is a lack of pressure is because there is a lack of gas. The reason for low pressure is that there is less and less gas above us for the atmosphere to support the higher we go.
The reason there is a lack of gas is down to gravity. OK.
Work is done when the state of a mass is changed from steady to accelerating. Usually we don’t see high acceleration except in cases like tornadoes, etc. More commonly work is done to raise or lower a mass of air.
In the lower atmosphere where an anticyclone (high pressure) is present for a long period what is the profile of temperature through the lower atmosphere and where a low pressure is present how does that change the temperature profile.? This sounds like a complicated topic that would take us far afield probably, but isn’t it interesting that in mid-latitude cyclones, high surface pressure correlates to cold surface temperatures. Not always mind you, because sometimes descending air in a high pressure system can lead to significant warming of the Chinook form. It is very difficult to come up with general answers isn’t it?
Jame sSexton, I didn’t see anything here about volume in the equations. Yes, the volume of the atmosphere does appear to change, it appears to match the activity of the Sun. But the mass doesn’t change a lot. The volume change would appear to alter the pressure gradient above the troposphere.
Will says:
December 29, 2011 at 1:00 pm
Sssh, no shouting (post Christmas hangover).
As I have said, I agree with your assertion regarding -18C and indeed that the atmosphere free Earth would exhibit its characteristic-emission temperature of 254.6K, 33.4 K cooler than today, at its characteristic-emission surface (which would of course change, as it is itself atmosphere dependant). That is still entirely consistent with the atmosphere producing 133k of warming if other factors (such as the water cycle) are producing a compensating cooling effect. You need to factor out everything else before ariving at the contribution of the atmosphere by itself.
I just have one comment for now before I do some more digesting. I am having a hard time believing that all other scientists currently working on the theory of AGW simply forgot to consider adiabatic heating due to atmospheric pressure. It doesn’t seem possible that such an obvious thing could be ignored. I kind of assumed that this effect had already been considered. I’d be interested to hear some folks from the IPCC respond to the ideas proposed here.
Dave Wendt says:
If you think it is significant, then assume some reasonable temperature range over the Earth and do the calculation. You will find that the difference between averaging the temperature and taking the 4th root of the average of T^4 is pretty small (a few degrees at most) for any reasonable approximation to earth-like temperature ranges.
Terry Oldberg says:
I have not misread it at all and I have explained exactly what they get wrong: Convection relaxes the temperature profile only back to the adiabatic lapse rate, not to a temperature profile that is independent of altitude as they assume.