Sentences with phrase «for volcanic aerosols»

The sea surface temperature anomalies for the East Pacific show cooling if they're adjusted for volcanic aerosols:

... our results indicate a greater role for volcanic aerosols in past decade - to - century climate than found in some previous work and a lesser, but still significant, role for solar forcing.»

But the first effect of SO2 is exactly the same as for volcanic aerosols: oxidizing to SO3 (via ozone and OH radicals), attracting water and the formation of reflecting drops.

The portion associated with short term forcings (solar, unaccounted - for volcanic aerosols, undercounts of Chinese pollution) will depend on their long term evolution — if they stabilise, you'd get a delay.

Not exact matches

Now, research suggests that for the past decade, such stratospheric aerosols — injected into the atmosphere by either recent volcanic eruptions or human activities such as coal burning — are slowing down global warming.

«Volcanic aerosols in the stratosphere absorb infrared radiation, thereby heating up the stratosphere, and changing the wind conditions subsequently,» said Dr. Matthew Toohey, atmospheric scientist at GEOMAR Helmholtz Centre for Ocean Research Kiel.

«I had done some work modeling aerosols produced by volcanic eruptions for other projects, so I started looking into how we might detect an eruption and what it would tell us.»

«The 1991 volcanic eruptions will substantially increase the aerosol loading within the polar vortex for 1992, both below and above 20 kilometres,» the team predicts.

While measurements of aerosol absorption in ultraviolet do not differentiate between the smoke, dust and ash aerosols, only volcanic clouds contain significant abundances of SO2, so satellite measurements of SO2 are especially valuable for unambiguous identification of volcanic clouds.

To the contrary, as there is an inverse correlation between low cloud cover and solar irradiation, and solar / volcanic have influences in the stratosphere, non-excisting for CO2 or human made aerosols.

runup from 1910 - 1940 than lack of volcanic activity and a better explanation for the 1940 - 1979 hiatus than industrial aerosol cooling.»

Further, during volcanic eruptions the ocean cools but for another reason: because volcanic aerosols shade the sun and thus the oceans are heated less than normal.

For instance, simulations were run that only used the changes in volcanic forcing, or in land use or in tropospheric aerosols.

There is no right answer for this, since we lack any basis to forecast whether a volcanic eruption will happen and what it's contribution to stratospheric aerosols will be.

In other words, if we are after a cause (or causes) for the temperature increase during the period in question, the presence or absence of aerosols from volcanic eruptions is beside the point, because they can not explain any increase in temperatures that occurred prior to any cooling effect they might have had.

Positing that there have been any times with zero volcanic aerosols is almost as ludicrous as positing there is no water vapor feedback; neither compares with trying to use them as the basis for a long winded attempt at justification for a wished for «safe» climate sensitivity.

Given the total irrelevance of volcanic aerosols during the period in question, the only very modest effect of fossil fuel emissions and the many inconsistencies governing the data pertaining to solar irradiance, it seems clear that climate science has no meaningful explanation for the considerable warming trend we see in the earlier part of the 20th century — and if that's the case, then there is no reason to assume that the warming we see in the latter part of that century could not also be due to either some as yet unknown natural force, or perhaps simply random drift.

The «lack of volcanic activity» has allowed the stratospheric aerosols responsible for such forcing to «dissipate» through the 1930s & 1940s.

«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.

The decay times of volcanic aerosols are approximately exponential, though there are seasonal and geographic influences *; Observations vary from ~ 5 to 95 months for 1 / e; eruption durations vary from week to decades; the mean time between VEI 4 eruptions is 18 months.

Some of those other forcings (sulphate and nitrate aerosols, land use changes, solar irradiance, volcanic aerosols, for instance) can cause cooling.

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).

Because such a struggle is the only reasonable explanation for why you fighting so hard against the idea that a dissipation of aerosols requires an absence of further volcanic activity.

There are various possible explanations for this discrepancy, but it is interesting to speculate that it could indicate that the models employed may have a basic inadequacy that does not allow a sufficiently strong AO response to large - scale forcing, and that this inadequacy could also be reflected in the simulated response to volcanic aerosol loading.

Any method to detect the real climate sensitivity for the four main climate drivers (GHGs, aerosols, solar, volcanic) is dependent of several assumptions and constraints.

For the period 1950 to 2005, it is exceptionally unlikely that the combined natural RF (solar irradiance plus volcanic aerosol) has had a warming influence comparable to that of the combined anthropogenic RF.

If so, there would appear to me to be little value in comparing the two when looking for aerosol sensitivity to volcanic eruptions.

Stratospheric ozone in models is erroneously being driven CFC emissions rather than ozone destroying sulphuric acid aerosols for stratospheric volcanic eruptions, and thus also providing a spurious anthropogenic post-2000 forcing.

It takes a couple of years for most of the aerosols from a large volcanic eruption to settle out of the air, so their cooling effect likewise lasts a couple of years.

Interestingly, the Crowley volcanic aerosols indicate a hemispheric imbalance that very closely matches the internal ~ 60 year cycle except for the 40s «bucket» issue.

Pinatubo shows that volcanic aerosols and cooling likely last for less than 5 years.

Basic physical science considerations, exploratory climate modeling, and the impacts of volcanic aerosols on climate all suggest that SWCE could partially compensate for some effects — particularly net global warming — of increased atmospheric CO2.

For the natural forcings Robock made various runs using different solar forcings and two runs using different volcanic aerosol numbers.

[i] This is treating missing 1861 - 1879 values as the same as for 1880, except for stratospheric (volcanic) aerosols.

This factor, when multiplied times the amount of reduction in tropospheric aerosol emissions, between 1975 and another later year will give the average global temperature for that year (per NASA's J - D land - ocean temperature index values) to within less than a tenth of a degree C. of actuality (when temporary natural variations due to El Nino's, La Nina's, and volcanic eruptions are accounted for).

I also agree that solar cycle's and volcanic aerosol effects account for much of the shorter term variation.

Add to that scaled monthly sunspot data to introduce the 0.1 deg C variations is surface temperature resulting from the solar cycle and add scaled monthly Stratospheric Aerosol Optical Depth data for dips and rebounds due to volcanic eruptions, and global surface temperature anomalies can be reproduced quite well.

2) There are errors in the assumed forcings, such as: a) AR5 let stratospheric aerosol concentration go to zero after 2000 (a sure way to prod the models into higher predictions), but it actually increased for the next 10 years «probably due to a large number of small volcanic eruptions».

Anomalies in the volcanic - aerosol induced global radiative heating distribution can force significant changes in atmospheric circulation, for example, perturbing the equator - to - pole heating gradient (Stenchikov et al., 2002; Ramaswamy et al., 2006a; see Section 9.2) and forcing a positive phase of the Arctic Oscillation that in turn causes a counterintuitive boreal winter warming at middle and high latitudes over Eurasia and North America (Perlwitz and Graf, 2001; Stenchikov et al., 2002, 2004, 2006; Shindell et al., 2003b, 2004; Perlwitz and Harnik, 2003; Rind et al., 2005; Miller et al., 2006).

Fourth, volcanic aerosols provide surfaces for heterogeneous chemistry affecting global stratospheric ozone distributions (Chipperfield et al., 2003) and perturbing other trace gases for a considerable period following an eruption.

«The forcings for ECHO - G are selected in advance by (1) choosing the strength and time series of solar irradiance variability; (2) choosing the strength and time series of volcanic aerosol variability and converting this to a surrogate time series of solar irradiance reductions, which are then added to (1); and (3) choosing the time series of greenhouse gas concentrations.

Aerosols emitted for only a short time would have minimal effects that subside very quickly.The industrial aerosols are rich in SO2, while apparently, the Chilean volcanic eruption did not (according the news item) spew enough SO2 into the atmosphere for discernible climate Aerosols emitted for only a short time would have minimal effects that subside very quickly.The industrial aerosols are rich in SO2, while apparently, the Chilean volcanic eruption did not (according the news item) spew enough SO2 into the atmosphere for discernible climate aerosols are rich in SO2, while apparently, the Chilean volcanic eruption did not (according the news item) spew enough SO2 into the atmosphere for discernible climate effects.

They're still using regression analysis to remove TSI, ENSO & volcanic aerosols from the instrument temperature record for attribution.

As for aerosols, you seem to be under the illusion that the only thing that matters is volcanic events, and even then only that they happen.

As for aerosols, the volcanic record is what it is, after Katmai there are no major eruptions, so that simplifies the aerosol record somewhat.

The basic science underlying this idea is pretty solid — large volcanic eruptions blast SO2 into the stratosphere where the sulfur aerosols naturally cool the globe for a few years.

This approach also accounts for the previously underestimated volcanic aerosol forcing, demonstrated by Santer et al. (2014), but not included in the GWPF report.

I had always thought that volcanic aerosols were not a fundamental «reason» for any temperature change — they simply masked and delayed the «real» rise.

Volcanic aerosols for example were almost ignored until their effect on historical climate was discovered.

Meanwhile, the authors do recognize natural solar forcing factors (17 % combined), natural ENSO variability (12 %), and volcanic aerosols (23 %) as assuming slightly more than half of the responsibility for temperature changes combined since the mid-1980s.