Sentences with phrase «radiative cooling from»

In the summer tropics, outgoing longwave radiative cooling from the surface to space is not effective in the high water vapour, optically thick environment of the tropical oceans.

The magnitude of this effect varies from model to model and leads to increased adiabatic heating of the polar regions, compensating in part the increased radiative cooling from CO2 increases.

Not exact matches

The model calculations, which are based on data from the CLOUD experiment, reveal that the cooling effects of clouds are 27 percent less than in climate simulations without this effect as a result of additional particles caused by human activity: Instead of a radiative effect of -0.82 W / m2 the outcome is only -0.60 W / m2.

Results show that the intrusion of dust from the Sahara Desert caused radiative cooling of Earth's surface.

During this event, the aerosols stayed close to the surface due to the presence of a anticyclone hovering over the study region at sea - level, «reducing the amount of shortwave irradiance reaching the surface and causing greater radiative cooling,» states Obregón, who likens the effects of desert dust with those resulting from certain forest fires or episodes of high pollution.

After radiative cooling, air subsiding from a warmer upper troposphere may eventually slowly warm the oceans.

That's far from the worst flaw in his calculation, since his two biggest blunders are the neglect of the radiative cooling due to sulfate aerosols (known to be a critical factor in the period in question) and his neglect of the many links in the chain of physical effects needed to translate a top of atmosphere radiative imbalance to a change in net surface energy flux imbalance.

You've got the radiative physics, the measurements of ocean temperature and land temperature, the changes in ocean heat content (Hint — upwards, whereas if if was just a matter of circulation moving heat around you might expect something more simple) and of course observed predictions such as stratospheric cooling which you don't get when warming occurs from oceanic circulation.

In other words, the same natural forcings that appear responsible for the modest large - scale cooling of the LIA should have lead to a cooling trend during the 20th century (some warming during the early 20th century arises from a modest apparent increase in solar irradiance at that time, but the increase in explosive volcanism during the late 20th century leads to a net negative 20th century trend in natural radiative forcing).

But the troposphere can still warm with an increased radiative cooling term because it is also balanced by heating through latent heat release, subsidence, solar absorption, increased IR flux from the surface, etc..

In chapter 11.3.6.3 they conclude: ``... it is concluded that the hiatus is attributable, in roughly equal measure, to a decline in the rate of increase in effective radiative forcing (ERF) and a cooling contribution from internal variability (expert judgment, medium confidence)».

A compelling argument for the positive longwave response is a leading alternate to Lindzen's IRIS although it receives less attention, and is known as the FAT hypothesis (from Dennis Hartmann) and arises from the fundamental physics of convection only heating the atmosphere where radiative cooling is efficient, and thus the temperature at the top of convective cloudiness should be near constant as it becomes warmer.

In general: even if the stratosphere as a whole cools (in terms of a decrease in total flux going out, to balance radiative forcings + radiative response from below), this doesn't necessarily mean cooling occurs throughout; there could be some portions that warm.

In the tugging on the temperature profile (by net radiant heating / cooling resulting from radiative disequilibrium at single wavelengths) by the absorption (and emission) by different bands, the larger - scale aspects of the temperature profile will tend to be shaped more by the bands with moderate amounts of absorption, while finer - scale variations will be more influenced by bands with larger optical thicknesses per unit distance (where there can be significant emission and absorption by a thinner layer).

Finally, you mention water vapour as a GHG... but water vapour is the main cooling component in the atmosphere, transporting heat from the surface to the radiative layer, so not really a true GHG.

Initially, shallow circulations driven by differential radiative cooling induce a self - aggregation of the convection into a single band, as has become familiar from simulations over idealized sea surfaces.

This cooling to the surface can actually be a pretty large source of cooling.To illustrate how important this is, the authors put this really informative table from some idealized radiative calculations.

Thus, while the net radiative effect of clouds is that of warming (cooling) across the tropics during La Niña (El Nino) events, the magnitude is quite small and varies greatly from one event to another..»

(5) Halpern et al. like many others do not understand that any supposed warming effect (or cooling effect) can not be derived from spectroscopic analyses or radiative transfer equations.

You write: «If internal variability (such a a cool PDO phase) reduces the rate of increase of surface temperature, while the e [x] ternal forcing still is increasing, this means the radiative imbalance is impeded from being cancelled by surface warming.»

If internal variability (such a a cool PDO phase) reduces the rate of increase of surface temperature, while the eternal forcing still is increasing, this means the radiative imbalance is impeded from being cancelled by surface warming.

The higher the concentration of «greenhouse» gases, the more optically thick the atmosphere, and therefore radiative cooling to space takes place from higher up in the atmosphere.

It may be quite close to LTE, but the departures from LTE can not be neglected when considering radiative heating and cooling.

For example, if the emissivity of two bodies is very different, there can be more radiative flux from the cooler one.

This is primarily based on the idea that the radiative flux would induce significant warming, but then the evaporation from the oceans and convective transport have a cooling effect.

Oceans warm and cool — the radiative imbalances changes from positive to negative.

So simply from basic thermodynamics and heat transfer considerations when you're dealing with a radiative imbalance El Nino is likely to heat the earth up as much as La Nina cools it.

In short, Lindzen's argument is that the radiative forcing from aerosols is highly uncertain with large error bars, and that they have both cooling (mainly by scattering sunlight and seeding clouds) and warming (mainly by black carbon darkening the Earth's surface and reducing its reflectivity) effects.

To understand why solar influence is so small, it's helpful to compare the radiative forcing from a cooling sun to the radiative forcing from anthropogenic greenhouse gases.

This includes radiative forcings such as a warming sun, cooling from sulfate aerosols or warming from CO2.

This «hiatus» is probably due to the cooling influences from natural radiative forcings (more volcanic eruptions and reducing output from the sun as part of the natural 11 - year solar cycle) and internal variability (fluctuations within the oceans unrelated to forcings).

It is not the infrared emission that cools the surface as in the so - called radiative equilibrium models because the net radiative heat transfer surface to air is about nil, but the evaporation whose thermostatic effect can not be overstated: increasing the surface temperature by +1 °C increases the evaporation by 6 %; where evaporation is 100 W / m ², this removes an additional 6 W / m ² from the surface.

(Yes, it does occur, even though John A will never concede the point, but of course, it is less than the radiative power from the warmer body to the cooler body.)

This lets me segue into another issue on this thread — radiative power from cooler bodies to warmer bodies.

The evaporative, conductive and radiative processes combined then set up a thermal gradient causing an upward flow of energy from water to air from where that 1 mm layer touches the ocean bulk below, up across the cooler layer then to the Knudsen layer by reversing the normal (warm at the top and cool at the bottom) temperature gradient which exists from that 1 mm layer down to the ocean bottom.

Between 801 and 1800 ce, the surface cooling trend is qualitatively consistent with an independent synthesis of terrestrial temperature reconstructions, and with a sea surface temperature composite derived from an ensemble of climate model simulations using best estimates of past external radiative forcings.

The primary drivers of these cloud changes appear to be increasing greenhouse gas concentrations and a recovery from volcanic radiative cooling.

In the idealised situation that the climate response to a doubling of atmospheric CO2 consisted of a uniform temperature change only, with no feedbacks operating (but allowing for the enhanced radiative cooling resulting from the temperature increase), the global warming from GCMs would be around 1.2 °C (Hansen et al., 1984; Bony et al., 2006).

The long term trend is that of cooling with a radiative forcing from 1850 to 2000 of -0.7 Wm - 2.

The shape of the CO2 band is such that, once saturated near the center over sufficiently small distances, increases in CO2 don't have much affect on the net radiative energy transfer from one layer of air to the other so long as CO2 is the only absorbing and emitting agent — but increases in CO2 will reduce the LW cooling of the surface to space, the net LW cooling from the surface to the air, the net LW cooling of the atmosphere to space (except in the stratosphere), and in general, it will tend to reduce the net LW cooling from a warmer to cooler layer when at least one of those layers contains some other absorbing / emitting substance (surface, water vapor, clouds) or is space)

The precipitation question is examined from either conserving energy in the troposphere (i.e. looking at the condensational heating term, with latent heating being balanced by radiative cooling) or at the surface (i.e. looking at the latent heating associated with evaporation).

Steve I will ask you to show the radiative heat transfer equation in which you input an emission from another body, gas / solid or fluid and show where it lowers the rate of cooling.

Gerlich and Tscheuschner, despite their apparent mastery of the mathematics of radiative transfer, don't know the difference between gross and net radiative flux, and they are apparently unaware of the concept of causality in an Einsteinian framework — a molecule of CO2 emitting a photon in a random direction can't know if there is a (cooler or warmer) surface in the direction of emission until time has elapsed for the photon to travel to the surface and back, and has no mechanism to remember from one photon to the next whether there was a source of photons in that direction, or what the apparent temperature of the emitter was.

By contrast, here are the heating / cooling rates from a comprehensive (= «standard») radiative - convective model, plotted against height instead of optical thickness.

Comparing the trend in global temperature over the past 100 - 150 years with the change in «radiative forcing» (heating or cooling power) from carbon dioxide, aerosols and other sources, minus ocean heat uptake, can now give a good estimate of climate sensitivity.

This hiatus in GMST rise is discussed in detail in Box 9.2 (Chapter 9), where it is concluded that the hiatus is attributable, in roughly equal measure, to a decline in the rate of increase in effective radiative forcing (ERF) and a cooling contribution from internal variability (expert judgment, medium confidence).

The lapse rate means that radiation is reaching space from ever - cooler regions — which also means that radiative efficacy decreases.

-LCB- 9.4, Box 9.2 -RCB- • The observed reduction in surface warming trend over the period 1998 to 2012 as compared to the period 1951 to 2012, is due in roughly equal measure to a reduced trend in radiative forcing and a cooling contribution from natural internal variability, which includes a possible redistribution of heat within the ocean (medium confidence).

In fact, that's exactly what we would expect from a super-strong greenhouse effect: the whole point of the greenhouse effect is that it decreases the rate at which the planet can cool, by decreasing radiative efficacy at (local) thermal wavelengths.

«Under these simplifying assumptions the amplification [f] of the global warming from a feedback parameter [b](in W m — 2 °C — 1) with no other feedbacks operating is 1 / (1 --[bκ — 1]-RRB-, where -LSB--- κ — 1] is the «uniform temperature» radiative cooling response (of value approximately — 3.2 W m — 2 °C — 1; Bony et al., 2006).