Sentences with phrase «aerosol concentrations not»

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

Not exact matches

But models are not tuned to the trends in surface temperature, and as Gavin noted before (at least for the GISS model), the aerosol amounts are derived from simulations using emissions data and direct effects determined by changes in concentrations.

It is not clear, however, to what extent changes in cloud droplet size are related to change in aerosol concentrations.

I've forgotten the details) a weaker cooling signal in the Arctic, where aerosol concentrations were low, which is not well understood.

So the whole basis for the study is flawed — its based on the affect of increasing aerosol concentrations that actually are not increasing.

First, if significant aerosol concentrations only cover, say, 10 % of the globe, doesn't that mean that to get a 0.5 degree cooling effect for the whole Earth, there must be a 5 degree cooling effect in the affected area.

«We show that the control of the droplet concentration (N), the environmental carrying - capacity (H0), and the cloud recovery parameter (τ) can be linked by a single nondimensional parameter (μ = √ N / (ατH0)-RRB-, suggesting that for deeper clouds the transition from open (oscillating) to closed (stable fixed point) cells will occur for higher droplet concentration (i.e., higher aerosol loading)...

First, the complicated models that develop emissions scenarios don't seem to be necessary for forcing the climate models; simply specifying a value of CO2 concentration (with the other greenhouse gases and anthropogenic aerosol) at 2100 along with a simple time trajectory is sufficient to force the climate model.

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.

«warming in the pipeline» usually assumes constant concentrations, not zero emissions (though if CO2 emissions were dropped to zero tomorrow, and all other emissions were held constant, I'd probably expect a little bit of warming before it turned over and started dropping) 2) Don't forget aerosols: they are following the Level 1 scenario from Wigley et al. 2009, and may actually dominate short - term temperature trends.

There can be no successful account of CO2, aerosols, and temperature until there is a scientific account of each, given in terms of physical hypotheses that describe natural processes, that enables the researchers to explain that the objects of their study, CO2 concentration, aerosol uptake, temperature records and such are not changing.

This study of course does not take away very different concerns related to stratospheric aerosol SRM geoengineering, like possible damage to the ozone layer [which in turn would be good news if you hate waiting for that spring tan] and the fact that allowing CO2 concentrations to keep rising presents other problems, like the necessity to never stop with the active process of SRM geoengineering, and increasing ecological damage caused by ocean acidification.

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.

But this information is not easily translated into aerosol radiative forcing, partly because we do not know what the pre-industrial concentrations were though direct observations, and because of the complexity of cloud - aerosol interactions (see Ch.

Concentrations of other greenhouse gases, which may have co-varied with CO2 on the multi-million-year time scale, are not known, and neither is the aerosol loading of the atmosphere or the external forcing of the climate changes on this time scale.

Figure 9.5 shows that simulations that incorporate anthropogenic forcings, including increasing greenhouse gas concentrations and the effects of aerosols, and that also incorporate natural external forcings provide a consistent explanation of the observed temperature record, whereas simulations that include only natural forcings do not simulate the warming observed over the last three decades.

Unfortunately it's a complicated picture, as clouds are not only influenced by climatic factors like temperature and evaporation, but also by concentrations of condensation nuclei — aerosols indeed.

But, much more important, models are not intended to predict well all the remaining physical variables of the weather - climate system that are all local in their essence: 3D - temperature (atmosphere and ocean), precipitation, 3D - wind (and ocean currents), 3D - radiance, 3D - cloudness, 3D - moisture content, 3D - aerosol concentration and transport, etc, etc, etc...

Additional output from the ACCMIP runs will include concentration / mass of radiatively active species, aerosol optical properties, and radiative forcings (clear and all sky) as well as important parameters that do not directly influence climate such as hydroxyl, chemical reaction rates, deposition rates, emission rates, surface pollutants and diagnostics of tracer transport.

However, the use of this term is not uniform when discussing stabilisation targets as some authors define carbon dioxide equivalent concentrations as the net forcing of all anthropogenic radiative forcing agents including greenhouse gases, tropospheric ozone, and aerosols but not natural forcings.

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.»

About aerosols, one thing to consider is that any natural background concentration of dust etc will not be forcings, by definition, we need to look only at changes.

Or perhaps you can point me to the dataset that shows, for several individual locations for the same period as the temperature set the: * CO2 concentrations (OK, we could use Mauna Loa for that) * Aerosols (sorry, can't use global records for that, there can be huge differences on a local scale) * Absolute humidity * TSI with correction for local albedo, including cloud albedo, and the place on earth.

You then asked «Or perhaps you can point me to the dataset that shows, for several individual locations for the same period as the temperature set the: * CO2 concentrations (OK, we could use Mauna Loa for that) * Aerosols (sorry, can't use global records for that, there can be huge differences on a local scale) * Absolute humidity * TSI with correction for local albedo, including cloud albedo, and the place on earth» Well actually, I can and have for the USA in terms of CO2, humidity (RH but AH also if you insist), and albedo, not to mention actual solar surface radiation, and various other variables (eg windspeed), as I have previously reported here for quite a few locations, eg Pt Barrow.