A new paper published in PNAS finds an astonishing deficiency and major false assumption of climate models, which has major implications for Arctic and global warming/climate change, the Earth's energy budget, and which is also another nail in the coffin for the overheated and falsified IPCC climate models. IMHO, it is effectively a death knell to conventional climate models and their projections, as well as the attribution statement of the IPCC based upon such models and blaming allegedly "more than 100%" of global warming on man-made greenhouse gas emissions.
The authors state climate models falsely assume water (71% of Earth's surface) is 100% efficient in emitting (and absorbing) far-infrared energy, but instead find "that is not the case," and that this discovery is allegedly a "previously unknown phenomenon."
Kirchhoff’s Law of Thermal Radiation dictates that emissivity is equal to absorptivity of a given material/liquid, and applies only to a true blackbody [which is a theoretical/laboratory construct that doesn't actually exist in the real world]. As this paper finds, the emissivity of far-IR by the oceans is only ~89% of the 100% "efficiency" of emission/absorption of a true blackbody. Thus, the oceans absorb only about ~89% of the far-IR from CO2 at 15 microns as shown by fig 3 below, and even less for longer greenhouse gas wavelengths in the far-IR. The remaining ~11% of far-IR emitted from CO2 is thus reflected rather than absorbed. [The authors define far-IR as 15-100 microns, and the peak absorption/emission of CO2 is at 15 microns in the far-IR.]
As I commented at WUWT, this allegedly "previously unknown phenomenon" should have been known due to the penetration depth in water of IR, which is only a few microns. That means IR from greenhouse gases can’t penetrate beyond the first 10 microns of the ocean skin surface, and all such energy is concentrated within the first few microns to cause evaporative cooling of the ocean skin surface. The ~89% or less of greenhouse gas far-infrared that is absorbed entirely within < 10 microns of the ocean skin surface is entirely used up in the phase change from liquid to gas and causes evaporative cooling, not warming, of the ocean skin surface.
IR from CO2 at 15 microns can only penetrate water < 10 microns
For all four of these physical reasons (and more)
- reduced absorption by the oceans of far-IR from greenhouse gases (~89% efficiency)
- ~11% reflection by ocean surfaces of far-IR from greenhouse gases
- penetration depth of water by far-IR from greenhouse gases of only a few microns, which causes evaporative cooling of the ocean skin surface
- cooling of the ocean skin surface by the ~89% of IR from greenhouse gases that is absorbed rather than reflected
This is a death knell for conventional climate models, which falsely assume the opposite of the four physical reasons above, thus falsely claiming IR from greenhouse gases can heat the oceans (70% of Earth's surface area) and where allegedly 90% of the "missing heat" has gone. This is impossible for the physical reasons noted above, and this new paper adds additional physical reasons why. As the authors find, the false emissivity/absorptivity assumptions of climate models results in a huge difference in model projections of Arctic temperatures by 2C after only 25 years, but the authors are apparently unaware of the reasons why only solar wavelengths can account for ocean warming/cooling, not IR from greenhouse gases.
In addition, as shown by measurements and a recent paper, the emissivity [which also equals absorption] of infrared radiation by water vapor in the atmosphere also declines with temperature, the opposite of a true blackbody for which the Kirchhoff, Planck, and Stefan-Boltzmann laws apply. Climate models assume the opposite that water acts as a true blackbody, yet another "basic physics" physical reason that blows the AGW theory out of the water.
|The emissivity [which also equals absorption] of infrared radiation by water vapor declines with temperature, the opposite of a true blackbody for which the Kirchhoff, Planck, and Stefan-Boltzmann laws apply|
Lower emissions of infra-red from snow and ice than from desert and ocean mean that less heat is lost from polar regions than other parts of the globe and this previously unreported mechanism may contribute to Arctic warming, say researchers.
Scientists have identified a mechanism that could turn out to be a big contributor to warming in the Arctic region and melting sea ice.
The research was led by scientists from the US Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab). They studied a long-wavelength region of the electromagnetic spectrum called far infrared. It’s invisible to our eyes but accounts for about half the energy emitted by the Earth’s surface. This process balances out incoming solar energy.
Despite its importance in the planet’s energy budget, it’s difficult to measure a surface’s effectiveness in emitting far-infrared energy. In addition, its influence on the planet’s climate is not well represented in climate models. The models assume that all surfaces are 100 percent efficient in emitting far-infrared energy.
That’s not the case. The scientists found that open oceans are much less efficient than sea ice when it comes to emitting in the far-infrared region of the spectrum. This means that the Arctic Ocean traps much of the energy in far-infrared radiation, a previously unknown phenomenon that is likely contributing to the warming of the polar climate.
Their research appears this week in the online early edition of the Proceedings of the National Academy of Sciences (PNAS).
“Far-infrared surface emissivity is an unexplored topic [for the "settled science"], but it deserves more attention. Our research found that non-frozen surfaces are poor emitters compared to frozen surfaces. And this discrepancy has a much bigger impact on the polar climate than today’s models indicate,” says Daniel Feldman, a scientist in Berkeley Lab’s Earth Sciences Division and lead author of the paper.
“Based on our findings, we recommend that more efforts be made to measure far-infrared surface emissivity. These measurements will help climate models better simulate the effects of this phenomenon on the Earth’s climate,” Feldman says.
He conducted the research with Bill Collins, who is head of the Earth Sciences Division’s Climate Sciences Department. Scientists from the University of Colorado, Boulder and the University of Michigan also contributed to the research.
The far-infrared region of the electromagnetic spectrum spans wavelengths that are between 15 and 100 microns (a micron is one-millionth of a meter). It’s a subset of infrared radiation, which spans wavelengths between 5 and 100 microns. In comparison, visible light, which is another form of electromagnetic radiation, has a much shorter wavelength of between 390 and 700 nanometers (a nanometer is one billionth of a meter).
Many of today’s spectrometers cannot detect far-infrared wavelengths, which explains the dearth of field measurements. Because of this, scientists have extrapolated the effects of far-infrared surface emissions based on what’s known at the wavelengths measured by today’s spectrometers.
Feldman and colleagues suspected this approach is overly simplistic, so they refined the numbers by reviewing published studies of far-infrared surface properties. They used this information to develop calculations that were run on a global atmosphere climate model called the Community Earth System Model, which is closely tied to the Department of Energy’s Accelerated Climate Model for Energy (ACME).
The simulations revealed that far-infrared surface emissions have the biggest impact on the climates of arid high-latitude and high-altitude regions.
In the Arctic, the simulations found that open oceans hold more far-infrared energy than sea ice, resulting in warmer oceans, melting sea ice, and a 2-degree Celsius increase in the polar climate after only a 25-year run.
This could help explain why polar warming is most pronounced during the three-month winter when there is no sun. It also complements a process in which darker oceans absorb more solar energy than sea ice.
“The Earth continues to emit energy in the far infrared during the polar winter,” Feldman says. “And because ocean surfaces trap this energy, the system is warmer throughout the year as opposed to only when the sun is out.”
The simulations revealed a similar warming affect on the Tibetan plateau, where there was five percent less snowpack after a 25-year run. This means more non-frozen surface area to trap far-infrared energy, which further contributes to warming in the region.
“We found that in very arid areas, the extent to which the surface emits far-infrared energy really matters. It controls the thermal energy budget for the entire region, so we need to measure and model it better,” says Feldman
The research was supported by NASA and the Department of Energy’s Office of Science.
PNAS describes the significance of this research as: We find that many of the Earth's climate variables, including surface temperature, outgoing longwave radiation, cooling rates, and frozen surface extent, are sensitive to far-IR surface emissivity, a largely unconstrained, temporally and spatially heterogeneous scaling factor for the blackbody radiation from the surface at wavelengths between 15 μm and 100 μm. We also describe a previously unidentified mechanism that amplifies high-latitude and high-altitude warming in finding significantly lower values of far-IR emissivity for ocean and desert surfaces than for sea ice and snow. This leads to a decrease in surface emission at far-IR wavelengths, reduced cooling to space, and warmer radiative surface temperatures. Far-IR emissivity can be measured from spectrally resolved observations, but such measurements have not yet been made.
Presently, there are no global measurement constraints on the surface emissivity at wavelengths longer than 15 μm, even though this surface property in this far-IR region has a direct impact on the outgoing longwave radiation (OLR) and infrared cooling rates where the column precipitable water vapor (PWV) is less than 1 mm. Such dry conditions are common for high-altitude and high-latitude locations, with the potential for modeled climate to be impacted by uncertain surface characteristics. This paper explores the sensitivity of instantaneous OLR and cooling rates to changes in far-IR surface emissivity and how this unconstrained property impacts climate model projections. At high latitudes and altitudes, a 0.05 change in emissivity due to mineralogy and snow grain size can cause a 1.8–2.0 W m−2 difference in the instantaneous clear-sky OLR. A variety of radiative transfer techniques have been used to model the far-IR spectral emissivities of surface types defined by the International Geosphere-Biosphere Program. Incorporating these far-IR surface emissivities into the Representative Concentration Pathway (RCP) 8.5 scenario of the Community Earth System Model leads to discernible changes in the spatial patterns of surface temperature, OLR, and frozen surface extent. The model results differ at high latitudes by as much as 2°K [or 2C], 10 W m−2, and 15%, respectively, after only 25 y of integration. Additionally, the calculated difference in far-IR emissivity between ocean and sea ice of between 0.1 and 0.2, suggests the potential for a far-IR positive feedback for polar climate change.
Far-infrared surface emissivity and climate by Daniel R. Feldman,William D. Collins, Robert Pincus, Xianglei Huang, and Xiuhong Chen published in the Proceedings of the National Academy of Sciences (PNAS) doi: 10.1073/pnas.1413640111.