Sentences with phrase «aerosol levels for»

Not exact matches

And for reasons that are not clear, positively charged bolts struck less frequently when the levels of silicon dioxide and other aerosols in the air were high.

Processes for which global - level boundaries can not yet be quantified are represented by gray wedges; these are atmospheric aerosol loading, novel entities, and the functional role of biosphere integrity.

Those missions include the Plankton, Aerosol, Cloud, ocean Ecosystem (PACE) satellite to monitor Earth's ocean health and atmosphere in 2022; the Orbiting Carbon Observatory - 3 experiment that would track carbon - dioxide levels from the International Space Station; the Climate Absolute Radiance and Refractivity Observatory (CLARREO) pathfinder Earth climate instrument for the ISS in 2020 time frame; and, finally, the Deep Space Climate Observatory (DSCOVR), a joint NASA - NOAA mission that is in orbit today and monitoring Earth from space.

During ISDAC, they collected an unprecedented level of data and detailed observations on Arctic clouds and aerosols, those tiny particles in the atmosphere that act as seeds for cloud droplets and ice crystals.

does fit the temperature trend to an acceptable level, if one should reduce the sensitivity for CO2 / aerosols far enough... Current models also can reproduce other transitions (LGM - Holocene) with a reasonable accuracy, but this is mainly in periods where there is a huge overlap between temperature (as initiator) and CO2 / CH4 levels (as feedback).

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

«On the other hand, we might assume that there has been some lower, but non-zero «background level» of volcanic aerosols - let's arbitrarily make it 2 on a scale of 10, for ease of discussion.

does fit the temperature trend to an acceptable level, if one should reduce the sensitivity for CO2 / aerosols far enough... Current models also can reproduce other transitions (LGM - Holocene) with a reasonable accuracy, but this is mainly in periods where there is a huge overlap between temperature (as initiator) and CO2 / CH4 levels (as feedback).

Since we would already be over 2C of warming with current CO2 levels, except for aerosols, isn't the safe amount of fossil fuels that can be burned zero?

Note to reporters: a scientist's willingness to make predictions of the future is an indication of the current level of understanding of the science; for example Hansen et al predicted that Pinatubo's eruption in 1991 would produce a significant aerosol cooling effect, and they were right; but would anyone be willing to predict that La Nina (assuming conditions set in) will result in a record hurricane season this fall?

I'm pretty sure you can get the grey version of that into a strat - cooling / trop - warming situation if you pick the strat absorbers right, but Andy is certainly right that non-grey effects play a crucial role in explaining quantitatively what is going on in the real atmosphere (that's connected with the non-grey explanation for the anomalously cold tropopause which I have in Chapter 4, and also with the reason that aerosols do not produce stratospheric cooling, and everything depends a lot on what level you are looking at).

Pollutant gas and aerosol emissions levels in the reference scenario were checked for consistency by estimating regional surface particulate and ozone levels using the MOZART atmospheric chemistry model.

But with the build - up to war economic output reflective aerosols would have been at a higher level — with greenhouse gases having gone stagnant for a good part of the previous decade and with methane having been hit even harder due to its short residence time.

One hears of dire predictions of sea - level rises which don't seem to be eventuating, of stasis in global temperatures that weren't predicted, of claimed ad - hoc appeals to aerosol effects, etc., and that's without going into the general atmosphere of hostility to people like me who genuinely think the case for harmful AGW effects looks shaky.

Chinese aerosols, deep ocean hide and seek, low level volcanism, «natural variability»... that stuff is so simple that priests and shamans have been doing it for millennia.

While there is a reduction in the impact of aerosols, at a global level, for some tropical regions, a shift towards higher concentrations is also reported.

Would you care to explain to me why you are confident about the estimates of atmospheric aerosol levels that are available for that period?

well, if it turns out to be useful for weather forecasting and dynamics at that level, perhaps it would prove useful in reducing the rather large uncertainty the GCM have with clouds and aerosols?

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.

Leaving aside the generally less well constrained results using the 1901 — 2010 period that started with two anomalously cold decades, none of these show scaling factors for «other anthropogenic» — predominantly aerosol and to a lesser extent ozone, with minor contributions from land use and other factors — that are consistent with unity at a 95 % confidence level.

Some point to aerosols (but that is not very plausible, as that should give an increase since 1975 for Europe and in part for North America), but I have the impression that increased water vapour levels are at the base of this change.

Aerosols are also essential for cloud formation in the troposphere: They act as condensation nuclei which even in the presence of low levels of water vapor do enable droplets to form.

Although computer models tend to agree that it's best to inject the aerosols into the stratosphere above the tropics or subtropics, and that the aerosols would disperse globally, the models differ on the extent of injection required for a given level of cooling, the authors wrote.

Hi Karsten, If you're still reading this, I'm still trying to get my head around the notion that we don't need to see much cooling under the most aerosol - laden areas for the direct effect to be strongly negative at the global level.

If there indeed was this slowdown in sea level rise, aerosols and ENSO would seem to possibly account for everything, including Figure 1 above.

If the low level aerosols act to actually warm, then it would be a highly regional warming, since the plumes would not have altitude sufficient to hold them aloft for long.

In the late 1970s the twin threats of global cooling and acid rain were the impetuous for creating regulations to curb above - ground - level aerosol / particulate pollution.

Natural Variability Doesn't Account for Observed Temperature Increase In it's press release announcement, NASA points out that while there are other factors than greenhouse gases contributing to the amount of warming observed — changes in the sun's irradiance, oscillations of sea surface temperatures in the tropics, changes in aerosol levels in the atmosphere — these factors are not sufficient to account for the temperature increases observed since 1880.

That seems the clearest statement yet of the real problem == is there anything that can replace current levels of air pollution, if high sulfur coal and oil are phased out for respiratory health reasons, that would make up for the loss of the aerosols» negative forcing on global temperature?

The level of scientific understanding of radiative forcing is ranked by the AR4 (Table 2.11) as high only for the long - lived greenhouse gases, but is ranked as low for solar irradiance, aerosol effects, stratospheric water vapor from CH4, and jet contrails.

Several observational studies (see Chapter 5) support the existence of the first aerosol indirect effect on low - level clouds and a negative sign for the associated radiative forcing, but these studies do not give indications on what a (negative) upper bound of the forcing would be.