Sentences with phrase «anthropogenic aerosol changes»

Topics that I work on or plan to work in the future include studies of: + missing aerosol species and sources, such as the primary oceanic aerosols and their importance on the remote marine atmosphere, the in - cloud and aerosol water aqueous formation of organic aerosols that can lead to brown carbon formation, the primary terrestrial biological particles, and the organic nitrogen + missing aerosol parameterizations, such as the effect of aerosol mixing on cloud condensation nuclei and aerosol absorption, the semi-volatility of primary organic aerosols, the importance of in - canopy processes on natural terrestrial aerosol and aerosol precursor sources, and the mineral dust iron solubility and bioavailability + the change of aerosol burden and its spatiotemporal distribution, especially with regard to its role and importance on gas - phase chemistry via photolysis rates changes and heterogeneous reactions in the atmosphere, as well as their effect on key gas - phase species like ozone + the physical and optical properties of aerosols, which affect aerosol transport, lifetime, and light scattering and absorption, with the latter being very sensitive to the vertical distribution of absorbing aerosols + aerosol - cloud interactions, which include cloud activation, the aerosol indirect effect and the impact of clouds on aerosol removal + changes on climate and feedbacks related with all these topics In order to understand the climate system as a whole, improve the aerosol representation in the GISS ModelE2 and contribute to future IPCC climate change assessments and CMIP activities, I am also interested in understanding the importance of natural and anthropogenic aerosol changes in the atmosphere on the terrestrial biosphere, the ocean and climate.

Not exact matches

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).

While a relatively minor part of the overall aerosol mass, changes in the anthropogenic portion of aerosols since 1750 have resulted in a globally averaged net radiative forcing of roughly -1.2 W / m2, in comparison to the overall average CO2 forcing of +1.66 W / m2.

To better understand what Kilimanjaro and other tropical glaciers are telling us about climate change, one ultimately ought to drive a set of tropical glacier models with GCM simulations conducted with and without anthropogenic forcing (greenhouse gases and sulfate aerosol).

This is one of the reasons why the most confident statements in IPCC are made with respect to the «Anthropogenic» changes all together since that doesn't require parsing out the (opposing) factors of GHGs and aerosols.

Basically, all of the warming trend in the last ~ 60 yrs is anthropogenic (a combination of greenhouse gases, aerosols, land use change, ozone etc.).

Also, due to the multiplicity of anthropogenic and natural effects on the climate over this time (i.e. aerosols, land - use change, greenhouse gases, ozone changes, solar, volcanic etc.) it is difficult to accurately define the forcings.

But more generally, something I've wondered is: while in the global annual average, aerosols could be said to partly cancel (net effect) the warming from anthropogenic greenhouse forcing, the circulatory, latitudinal, regional, seasonal, diurnal, and internal variability changes would be some combination of reduced changes from reduced AGW + some other changes related to aerosol forcing.

Summary for Policymakers Chapter 1: Introduction Chapter 2: Observations: Atmosphere and Surface Chapter 3: Observations: Ocean Chapter 4: Observations: Cryosphere Chapter 5: Information from Paleoclimate Archives Chapter 6: Carbon and Other Biogeochemical Cycles Chapter 7: Clouds and Aerosols Chapter 8: Anthropogenic and Natural Radiative Forcing Chapter 8 Supplement Chapter 9: Evaluation of Climate Models Chapter 10: Detection and Attribution of Climate Change: from Global to Regional Chapter 11: Near - term Climate Change: Projections and Predictability Chapter 12: Long - term Climate Change: Projections, Commitments and Irreversibility Chapter 13: Sea Level Change Chapter 14: Climate Phenomena and their Relevance for Future Regional Climate Change Chapter 14 Supplement Technical Summary

The declining signal over India shown by the GPCP decadal mode is broadly consistent with gauge measurements since the 1950s — that several research groups including my own are trying to understand, perhaps relating to emissions of anthropogenic aerosol — although there are discrepancies between these gauge - based data sets themselves (see our recent review in Nature Climate Change, for example).

Multi-signal detection and attribution analyses, which quantify the contributions of different natural and anthropogenic forcings to observed changes, show that greenhouse gas forcing alone during the past half century would likely have resulted in greater than the observed warming if there had not been an offsetting cooling effect from aerosol and other forcings.

One driver of temperatures in this region is the abundance and variability of ozone, but water vapor, volcanic aerosols, and dynamical changes such as the Quasi - Biennial Oscillation (QBO) are also significant; anthropogenic increases in other greenhouse gases such as carbon dioxide play a lesser but significant role in the lower stratosphere.

However, although models simulate a decrease in DTR when they include anthropogenic changes in greenhouse gases and aerosols, the observed decrease is larger than the model - simulated decrease (Stone and Weaver, 2002, 2003; Braganza et al., 2004).

This is the portion of temperature change that is imposed on the ocean - atmosphere - land system from the outside and it includes contributions from anthropogenic increases in greenhouse gasses, aerosols, and land - use change as well as changes in solar radiation and volcanic aerosols.

Changes in atmospheric composition from human activities are the main cause of anthropogenic climate change by enhancing the greenhouse effect, although with important regional effects from aerosol particulates (IPCC 2007).

The most important factors are anthropogenic emissions of greenhouse gases, land use changes and emissions of aerosols.

Note, OA stands for Other Anthropogenic factors, primarilly the aerosol direct and indirect effects and Land Use Change, all of which are negative forcings.

``... snow pack has decreased and been observed to melt earlier in the calendar year... the observed changes in the hydrological components... can be explained well by anthropogenic forcing (green house gases and aerosols) alone.»

Additionally, changes in anthropogenic sulfate aerosol forcing have been proposed as the dominant cause of the AMV and the historical multidecadal variations in Atlantic tropical storm frequency, based on some model simulations including aerosol indirect effects.

The observed North Atlantic sulfate aerosol optical depth has not increased (but shows a modest decline) over this period, suggesting the decline of the Atlantic major hurricane frequency during 2005 — 2015 is not likely due to recent changes in anthropogenic sulfate aerosols.

Only if there was a significant chance of the anthropogenic aerosols actually having a net warming effect would this change the conclusion and evidence for this is sorely lacking.

The model encompassed changes in CO2, solar irradiance, other anthropogenic forcings (e.g., aerosols), and other variables.

Primary emphasis is placed on investigation of climate sensitivity — globally and regionally, including the climate system's response to diverse forcings such as solar variability, volcanoes, anthropogenic and natural emissions of greenhouse gases and aerosols, paleo - climate changes, etc..

It is self evident that anthropogenic greenhouse gas emissions, aerosols, and land use changes are candidates for this type of application.

And what exactly would be changed, if the public were educated about aerosols and greenhouse gases and temperature histories and the fact that at least 50 % of the 0.5 - 0.9 C change compared to 200 years ago is with 90 to 99 % likelihood due to the net effect of anthropogenic factors?

The model that I have described, warming due to the removal of anthropogenic SO2 aerosols, largely due to clean air efforts, perfectly matches the behavior of climate change over the past 40 years.

The effect of anthropogenic black carbon (BC) aerosol on snow is of enduring interest due to its role in aerosol radiative forcing and further consequences for Arctic and global climate change.

a) that natural forcing represented 7 % of the total forcing b) that all anthropogenic forcing componenets other than CO2 (other GHGs, aerosols, land use changes, etc.) cancelled one another out, so that forcing from CO2 = total anthropogenic forcing c) that the CO2 / temperature relation is logarithmic

The authors find that the results from each of these analyses are consistent, showing that the effects of changes in greenhouse gases, aerosols and other anthropogenic forcings on the climate of the Arctic region can be detected.

In order to better understand the causes of the Arctic's changing climate, the authors used observational data and nine CMIP5 global climate models to tease apart the effects of anthropogenic greenhouse gas emissions, natural forcings and other anthropogenic forcings (aerosols, ozone and land use changes).

To slow the rate of anthropogenic - induced climate change in the 21st century and to minimize its eventual magnitude, societies will need to manage the climate forcing factors that are directly influenced by human activities, in particular greenhouse gas and aerosol emissions.

IPCC AR4 WG1 tells us that the all anthropogenic forcing components except CO2 (aerosols, other GHGs, land use changes, other changes in surface albedo, etc.) have essentially cancelled one another out, so we can use the estimated radiative forcing for CO2 (1.66 W / m ^ 2) to equate with total net anthropogenic forcing (1.6 W / m ^ 2).

It is easy but somewhat speculative to invoke combinations of solar changes, aerosols (anthropogenic and volcanic), and internal climate modes to explain the deviations from a smoothly rising curve, and there are ample data to indicate these played a role.

If one were to assume that non-volcanic OHC anomalies approximately correlate with ENSO (as the results of Balmaseda et al. seem to confirm), one is left with changes in external forcing which the FR11 method would certainly miss, namely anthropogenic aerosols and recent changes in volcanic aerosols.

Figure 10.4 of AR5, reproduced as Figure 2 below, shows in panel (b) estimated scaling factors for three forcing components: natural (blue bars), GHG (green bars) and «other anthropogenic» — largely aerosols, ozone and land use change (yellow bars).

In order to account for this they make a comparison between natural and pre-industrial (including anthropogenic) aerosol conditions in HadGEM2 - A historical runs and derive an adjustment factor for change from preindustrial.

Theoretical and Applied Climatology covers climate modeling, climatic changes and climate forecasting, micro - to mesoclimate, applied meteorology as in agro - and forestmeteorology, biometeorology, building meteorology and atmospheric radiation problems as they relate to the biosphere; effects of anthropogenic and natural aerosols or gaseous trace constituents; hardware and software elements of meteorological measurements, including techniques of remote sensing, among other topics of current interest.

The internally imposed structural changes to the climate system include the injection of the non-condensing greenhouse gases (CO2, CH4, N2O, CFCs, etc), volcanic and anthropogenic aerosols, and episodic contact to the deep ocean cold temperature reservoir (this is responsible for the «natural», «internally forced», or «unforced» variability of the climate system).

We know there are effects from land use change and we know we have added to atmospheric backscatter of solar radiation from particulates (sulfate aerosols, dust from agriculture...) but we are no longer certain of the net sign of anthropogenic temperature change.

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.

Overall, we find that anthropogenic greenhouse gases and sulphate aerosols have had a detectable influence on sea - level pressure over the second half of the twentieth century: this represents evidence of human influence on climate independent of measurements of temperature change.»

Aerosols of anthropogenic origin are responsible for a radiative forcing (RF) of climate change through their interaction with radiation, and also as a result of their interaction with clouds.

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.»

Linkages of the observed changes in the diurnal temperature range to large - scale climate forcings, such as anthropogenic increases in sulfate aerosols, greenhouse gases, or biomass burning (smoke), remain tentative.

I think it is really important to make that distinction - that there are a number of factors that influence the extent of Arctic sea ice, some of them of course associated with changes in the radiative forcing from the atmosphere, as a result of anthropogenic greenhouse gases and aerosols, but also changes in the atmospheric circulation and also the advection of heat into or out of the Arctic by the ocean circulation.

There have been numerous research papers and reviews published over the past 10 years, including several in prestigious journals such as Nature and Science, that conclude that the observed temperature changes over the past 100 years are consistent with the combined changes in atmospheric aerosols (volcanic and anthropogenic), land surface changes, variations in solar irradiance and increases in greenhouse gases.

(c) There is a debate about the attribution (causes) of past warming — which probably varied over time — between natural drivers (e.g., rebound from the Little Ice Age, solar influences) and anthropogenic drivers (eg, CO2, aerosols, land use changes).

The forcing agents are long - lived greenhouse gases (GHG), anthropogenic aerosols (AA), land - use changes (LU), ozone (Oz), solar (SI) and volcanoes (VI).

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).

The six individual forcings analysed were well - mixed greenhouse gases (GHG), anthropogenic aerosols, ozone, land use change, solar variations and volcanoes.