Sentences with phrase «average volcanic forcing»

Thus the RCP scenarios assume the long - term average volcanic forcing in the future, and they hold it constant, which is reasonable because as you say we can't predict the next eruption.

Not exact matches

Recently I have been looking at the climate models collected in the CMIP3 archive which have been analysed and assessed in IPCC and it is very interesting to see how the forced changes — i.e. the changes driven the external factors such as greenhouse gases, tropospheric aerosols, solar forcing and stratospheric volcanic aerosols drive the forced response in the models (which you can see by averaging out several simulations of the same model with the same forcing)-- differ from the internal variability, such as associated with variations of the North Atlantic and the ENSO etc, which you can see by looking at individual realisations of a particular model and how it differs from the ensemble mean.

The straight line for Scenario B in RC's image is misleading because it presumably averages out the volcanic forcings of over the time period.

Volcanic impact is «small» when the forcing is «global» only because a portion of the short term impact is «averaged» out.

«Here, it is sufficient to note that many of the 20CEN / A1B simulations neglect negative forcings arising from stratospheric ozone depletion, volcanic dust, and indirect aerosol effects on clouds... It is likely that omission of these negative forcings contributes to the positive bias in the model average TLT trends in Figure 6F.

Current computer models can faithfully simulate many of the important aspects of the global climate system, such as changes in global average temperature over many decades; the march of the seasons on large spatial scales; and how the climate responds to large - scale forcing, like a large volcanic eruption.

The most likely candidate for that climatic variable force that comes to mind is solar variability (because I can think of no other force that can change or reverse in a different trend often enough, and quick enough to account for the historical climatic record) and the primary and secondary effects associated with this solar variability which I feel are a significant player in glacial / inter-glacial cycles, counter climatic trends when taken into consideration with these factors which are, land / ocean arrangements, mean land elevation, mean magnetic field strength of the earth (magnetic excursions), the mean state of the climate (average global temperature), the initial state of the earth's climate (how close to interglacial - glacial threshold condition it is) the state of random terrestrial (violent volcanic eruption, or a random atmospheric circulation / oceanic pattern that feeds upon itself possibly) / extra terrestrial events (super-nova in vicinity of earth or a random impact) along with Milankovitch Cycles.

Capt. Dallas: That would provide an estimate of «average» volcanic aerosol forcing.

Using 1859 — 1882 for the base period and 1995 — 2011 for the final period, thus avoiding major volcanic activity, median estimates are derived for ECS of 1.64 K and for TCR of 1.33 K. ECS 17 — 83 and 5 — 95 % uncertainty ranges are 1.25 — 2.45 and 1.05 — 4.05 K; the corresponding TCR ranges are 1.05 — 1.80 and 0.90 — 2.50 K. Results using alternative well - matched base and final periods provide similar best estimates but give wider uncertainty ranges, principally reflecting smaller changes in average forcing.

That would provide an estimate of «average» volcanic aerosol forcing.

They think that the only way for global - average temperatures to change is for the climate system to be forced «externally»... by a change in the output of the sun, or by a large volcanic eruption.

Moreover, using long time periods for averaging makes it impossible to avoid major volcanic eruptions, which involve uncertainty as to the large forcing excursions involved and their effects.