Sentences with phrase «atmospheric aerosol concentration»

It is my understanding that the uncertainties regarding climate sensitivity to a nominal 2XCO2 forcing is primarily a function of the uncertainties in (1) future atmospheric aerosol concentrations; both sulfate - type (cooling) and black carbon - type (warming), (2) feedbacks associated with aerosol effects on the properties of clouds (e.g. will cloud droplets become more reflective?)

via changes in cloud cover, ice cover, atmospheric aerosols concentrations and distributions) is incomplete and contains uncertainties on the order of the estimates of the forcing changes themselves. . .

As a result, not only did atmospheric aerosol concentrations not quadruple, they declined starting in the late 1970s:

Models suggest atmospheric aerosol concentrations will increase as the temperatures keep climbing — and that's bad news for your lungs.

Not exact matches

After allowing for humidity and rainfall, they found that «aerosol optical thickness» — a measure of the concentration of atmospheric particles — decreased by only 10 to 15 per cent compared with the same periods in 2002 to 2007 (Geophysical Research Letters, in press).

Non-polar glacial ice holds a wealth of information about past changes in climate, the environment and especially atmospheric composition, such as variations in temperature, atmospheric concentrations of greenhouse gases and emissions of natural aerosols or human - made pollutants... The glaciers therefore hold the memory of former climates and help to predict future environmental changes.

The relative atmospheric concentrations of greenhouse gases as well as aerosol and particulate content coupled with other climate information gives insight into both the importance of these as drivers of temperature as well as how these drivers might couple in either a positive or negative feedback sense (Beckman and Mahoney, 1998).

The main research themes include greenhouse gas concentrations and ecosystem — atmosphere fluxes, the climate effects of atmospheric aerosols, aerosol — cloud interactions and air quality.

However, I am not a «warmista» by any means — we do not know how to properly quantify the albedo of aerosols, including clouds, with their consequent negative feedback effects in any of the climate sensitivity models as yet — and all models in the ensemble used by the «warmistas» are indicating the sensitivities (to atmospheric CO2 increase) are too high, by factors ranging from 2 to 4: which could indicate that climate sensitivity to a doubling of current CO2 concentrations will be of the order of 1 degree C or less outside the equatorial regions (none or very little in the equatorial regions)- i.e. an outcome which will likely be beneficial to all of us.

temperature, other climatic variables, and concentrations of aerosols and trace gases; and (2) making raw and processed atmospheric measurements accessible in a form that enables a number of different groups to replicate and experiment with the processing of the more widely disseminated data sets such as the MSU tropospheric temperature record.

The prominent upward trend in the GM precipitation occurring in the last century and the notable strengthening of the global monsoon in the last 30 yr (1961 — 90) appear unprecedented and are due possibly in part to the increase of atmospheric carbon dioxide concentration, though the authors» simulations of the effects from recent warming may be overestimated without considering the negative feedbacks from aerosols.

The parameterization is intended for application in large - scale atmospheric and cloud models that can predict 1) the supersaturation of water vapor, which requires a representation of vertical velocity on the cloud scale, and 2) concentrations of a variety of insoluble aerosol species.

Consequently, the most advanced climate models now require, in addition to concentrations or emissions of greenhouse gases (CO2, CH4, N2O and halocarbons), emissions of reactive gases and aerosol precursor compounds (SO2, NOx, VOC, BC, OC and NH3), to model atmospheric chemistry and interactions with the climate system.6 For most variables, a sectoral differentiation would improve the quality of the calculations (e.g. from power plants and agricultural burning).

28 29 7.4.5.2 Physical Mechanisms Linking Cosmic Rays to Cloudiness 30 31 The most widely studied mechanism proposed to explain the possible link between GCR and cloudiness is 32 the «ion - aerosol clear air» mechanism, in which atmospheric ions produced by GCR facilitate aerosol 33 nucleation and growth ultimately impacting CCN concentrations and cloud properties (Carslaw et al., 2002; 34 Usoskin and Kovaltsov, 2008).

The most widely studied mechanism proposed to explain the possible link between GCR and cloudiness is the «ion - aerosol clear air» mechanism, in which atmospheric ions produced by GCR facilitate aerosol nucleation and growth ultimately impacting CCN concentrations and cloud properties (Carslaw et al., 2002; http://www.sciencemag.org/content/298/5599/1732.abstract

Most CM experiments based on RCPs will be driven by greenhouse gas concentrations (Hibbard et al. 2007).8 Furthermore, many Earth system models do not contain a full atmospheric chemistry model, and thus require exogenous inputs of three - dimensional distributions for reactive gases, oxidant fields, and aerosol loadings.

Using water to represent the atmosphere and milk droplets to represent aerosols, students make predictions and conduct investigations to discover how different aerosol concentrations affect atmospheric color and visibility.

These NCA emissions directly affect particle concentrations and human exposure to nanosized aerosol in urban areas, and potentially may act as nanosized condensation nuclei for the condensation of atmospheric low - volatile organic compounds.

The direct RF due to nitrate aerosol is therefore sensitive to atmospheric concentrations of ammonia as well as NOx emissions.

It is uncertain how a given emissions path converts into atmospheric concentrations of the various radiatively active gases or aerosols.

«Reducing the wide range of uncertainty inherent in current model predictions of global climate change will require major advances in understanding and modeling of both (1) the factors that determine atmospheric concentrations of greenhouse gases and aerosols, and (2) the so - called «feedbacks» that determine the sensitivity of the climate system to a prescribed increase in greenhouse gases.»

Sulfate aerosols wash out pretty quickly, so their current atmospheric concentration (and the resulting negative forcing) is mainly determined by the current emissions levels.

Models that attempt to perform reliable projections of future climate changes should account explicitly for the feedbacks between climate and the processes that determine the atmospheric concentrations of greenhouse gases, reactive gases and aerosol particles.

I was at an international conference on aerosol in September and I made a comment that we're getting to the stage with CLOUD where we will understand the processes extremely well, but we still won't be able to reduce the errors because we don't have good enough atmospheric observations of what the concentrations of these vapors are in the atmosphere versus altitude.

The annual average is about 0.25 of the peak — but you expect as well that the reflected SW would not vary as much as you suggest albedo of oceans being influenced by «solar zenith angle, wind speed, transmission by atmospheric cloud / aerosol, and ocean chlorophyll concentration.»

«Measurements at a sea platform show that the ocean surface albedo is highly variable and is sensitive to four physical parameters: solar zenith angle, wind speed, transmission by atmospheric cloud / aerosol, and ocean chlorophyll concentration.»

Over the next decade, changes in climate are expected to be due to a combination of anthropogenic changes in atmospheric greenhouse - gas and aerosol concentrations; natural variations in volcanic and solar activity, and natural, unforced internal variability.

Additionally, solar spectral measurements provide information about atmospheric composition including column concentrations of trace gases and aerosol optical properties and optical depths.

The relative atmospheric concentrations of greenhouse gases as well as aerosol and particulate content coupled with other climate information gives insight into both the importance of these as drivers of temperature as well as how these drivers might couple in either a positive or negative feedback sense.

The relative atmospheric concentrations of greenhouse gases as well as aerosol and particulate content coupled with other climate information gives insight into both the importance of these as drivers of temperature as well as how these drivers might couple in either a positive or negative feedback sense (Beckman and Mahoney, 1998).

The 2007 Fourth Assessment Report compiled by the IPCC (AR4) noted that «changes in atmospheric concentrations of greenhouse gases and aerosols, land cover and solar radiation alter the energy balance of the climate system», and concluded that «increases in anthropogenic greenhouse gas concentrations is very likely to have caused most of the increases in global average temperatures since the mid-20th century».

Emissions scenarios were converted to projections of atmospheric GHG and aerosol concentrations, radiative forcing of the climate, effects on regional climate, and climatic effects on global sea level (IPCC, 2001a).

In the thread on Confidence in Radiative Transfer Models, we argued that line - by - line radiative transfer codes and the best band models can accurately simulate clear sky (no clouds, aerosols) infrared radiation fluxes at the surface provided that the vertical profiles of atmospheric temperature and trace gas concentrations are specified accurately.