Sentences with phrase «stratospheric aerosol changes»

Near - global satellite aerosol data imply a negative radiative forcing due to stratospheric aerosol changes over this period of about — 0.1 watt per square meter, reducing the recent global warming that would otherwise have occurred.

An analysis of the very recent studies of stratospheric aerosol changes following a giant solar energetic particles event shows a similar negligible effect.

Near - global satellite aerosol data imply a negative radiative forcing due to stratospheric aerosol changes over this period of about — 0.1 W / m2, reducing the recent global warming that would otherwise have occurred.

Not exact matches

The Persistently Variable «Background» Stratospheric Aerosol Layer and Global Climate Change

There are multiple anthropogenic forcings that have quite different impacts (e.g. anthropogenic greenhouse gas increases, aerosols, land - use changes and, yes, stratospheric ozone depletion).

Stratospheric heating by potential geoengineering aerosols Geoengineering aerosols change stratospheric radiative heating rates Heating rates depend on aerosol speStratospheric heating by potential geoengineering aerosols Geoengineering aerosols change stratospheric radiative heating rates Heating rates depend on aerosol spestratospheric radiative heating rates Heating rates depend on aerosol species and size

It hardly takes imagination to posit that while initial aerosol dimming might depress temperatures, the aerosols and atmosphere might react in ways that change heat balance in other directions as they disperse, through stratospheric chemistry, and the fact that, unsurprisingly, there is a difference in aerosol behaviour depending on day vs night (you can't reduce the sunlight that reaches the south pole on June 23rd....).

But that was within the constraints of the model (no change in aerosol influence, lack of solar stratospheric influences, no influence of solar on cloud cover...).

First, for changing just CO2 forcing (or CH4, etc, or for a non-GHE forcing, such as a change in incident solar radiation, volcanic aerosols, etc.), there will be other GHE radiative «forcings» (feedbacks, though in the context of measuring their radiative effect, they can be described as having radiative forcings of x W / m2 per change in surface T), such as water vapor feedback, LW cloud feedback, and also, because GHE depends on the vertical temperature distribution, the lapse rate feedback (this generally refers to the tropospheric lapse rate, though changes in the position of the tropopause and changes in the stratospheric temperature could also be considered lapse - rate feedbacks for forcing at TOA; forcing at the tropopause with stratospheric adjustment takes some of that into account; sensitivity to forcing at the tropopause with stratospheric adjustment will generally be different from sensitivity to forcing without stratospheric adjustment and both will generally be different from forcing at TOA before stratospheric adjustment; forcing at TOA after stratospehric adjustment is identical to forcing at the tropopause after stratospheric adjustment).

Recently I have been looking at the climate models collected in the CMIP3 archive which have been analysed and assessed in IPCC and it is very interesting to see how the forced changes — i.e. the changes driven the external factors such as greenhouse gases, tropospheric aerosols, solar forcing and stratospheric volcanic aerosols drive the forced response in the models (which you can see by averaging out several simulations of the same model with the same forcing)-- differ from the internal variability, such as associated with variations of the North Atlantic and the ENSO etc, which you can see by looking at individual realisations of a particular model and how it differs from the ensemble mean.

Instead, they discuss new ways of playing around with the aerosol judge factor needed to explain why 20th - century warming is about half of the warming expected for increased in GHGs; and then expand their list of fudge factors to include smaller volcanos, stratospheric water vapor (published with no estimate of uncertainty for the predicted change in Ts), transfer of heat to the deeper ocean (where changes in heat content are hard to accurately measure), etc..

«The Persistently Variable «Background» Stratospheric Aerosol Layer and Global Climate Change.»

Pitari, G., E. Mancini, V. Rizi, and D. Shindell, 2002: Feedback of future climate and sulfur emission changes an stratospheric aerosols and ozone, J. Atmos.

Small forcings due to changes in desert dust aerosols and the pseudo-forcing due to changes in stratospheric water vapor might to some extent be non-anthropogenic in nature.

Future emails will include: the difference between contrails / vapour trails and Stratospheric Aerosol Injection observations on covert atmospheric spraying (their tactics have changed in the last few weeks — this has been noticed globally) who is controlling the spraying — who are «they» much of the northern hemisphere is burning — California, Canada, Siberia (2,000 mile smoke clouds), Sweden etc..

«We use 1280 years of control simulation, with constant preindustrial forcings including constant specified CO2, and a five - member ensemble of historical simulations from 1850 — 2005 including prescribed historical greenhouse gas concentrations, SO2 and other aerosol - precursor emissions, land use changes, solar irradiance changes, tropospheric and stratospheric ozone changes, and volcanic aerosol (ALL), following the recommended CMIP5 specifications.

These include the influences of a changing climate, altered air mixing and transport rates, energy exchange, and changes in the composition of the atmosphere (e.g., water vapor, methane, nitrous oxide, aerosols, etc.), all of which can influence stratospheric ozone.

Solomon, S., J. S. Daniel, R. R. Neely, J. - P. Vernier, E. G. Dutton, and L. W. Thomason, 2011: The persistently variable «background» stratospheric aerosol layer and global climate change.

Global temps vary for many reasons beyond CO2 levels including but not limited to: planetary motion, changes in albedo, stratospheric aerosols, and solar variability to name a few, but the only area of genuine study by the IPCC has been rising CO2 levels.

He thus avoids sullying himself with the consideration of what would constitute the lesser of two evils — a climate - changed world without stratospheric aerosols, or one with them.

Although we focus on a hypothesized CR - cloud connection, we note that it is difficult to separate changes in the CR flux from accompanying variations in solar irradiance and the solar wind, for which numerous causal links to climate have also been proposed, including: the influence of UV spectral irradiance on stratospheric heating and dynamic stratosphere - troposphere links (Haigh 1996); UV irradiance and radiative damage to phytoplankton influencing the release of volatile precursor compounds which form sulphate aerosols over ocean environments (Kniveton et al. 2003); an amplification of total solar irradiance (TSI) variations by the addition of energy in cloud - free regions enhancing tropospheric circulation features (Meehl et al. 2008; Roy & Haigh 2010); numerous solar - related influences (including solar wind inputs) to the properties of the global electric circuit (GEC) and associated microphysical cloud changes (Tinsley 2008).

Cointegration indicates that internal climate variability and / or the omission of some components of radiative forcing (e.g., stratospheric water vapor, black or organic carbon, nitrite aerosols, etc.) do not impart a stochastic or deterministic trend that would interfere with the interpretation of temperature changes at the subdecadal scale (SI Appendix).

Pitari, G., E. Mancini, V. Rizi, and D.T. Shindell, 2002: Impact of future climate and emission changes on stratospheric aerosols and ozone.

Zonal mean atmospheric temperature change from 1890 to 1999 (°C per century) as simulated by the PCM model from (a) solar forcing, (b) volcanoes, (c) wellmixed greenhouse gases, (d) tropospheric and stratospheric ozone changes, (e) direct sulphate aerosol forcing and (f) the sum of all forcings.

The persistently variable «background» stratospheric aerosol layer and global climate change

But to quantify the influences (or «forcings» in climate jargon) even further, they considered three anthropogenic forcings — well - mixed greenhouse gases, sulfate aerosols, and tropospheric and stratospheric ozone — as well as two natural forcings — changes in solar irradiance and volcanic aerosols — all of which are likely to influence tropopause height.»

Forster et al. (2007) described four mechanisms by which volcanic forcing influences climate: RF due to aerosol — radiation interaction; differential (vertical or horizontal) heating, producing gradients and changes in circulation; interactions with other modes of circulation, such as El Niño - Southern Oscillation (ENSO); and ozone depletion with its effects on stratospheric heating, which depends on anthropogenic chlorine (stratospheric ozone would increase with a volcanic eruption under low - chlorine conditions).

Figure 4 shows that changes in several external forcings over the ETCW could be important, such as: a greenhouse gas increase, a small change in solar irradiance, and a reduction in stratospheric aerosols associated with reduced volcanic activity.