Sentences with phrase «atmospheric circulation trends»

While we have not evaluated all of the feedback mechanisms and internal and external forcing factors involved, we have shown evidence that the West Antarctic warming is consistent with the regional decline of sea ice in the ABS and with the atmospheric circulation trends over the Southern Oceans.

This is important in that the atmospheric circulation trends over the Antarctic vary substantially by season, with summer and autumn exhibiting decreases in sea level pressure over the circumpolar trough and over the continent.

Regardless of the exact reasons for differences in the TOGA and GOGA experiments, the model results support the notion that SSTs in the tropics to subtropics have played a role in forcing the atmospheric circulation trends over the SH in austral spring.

Not exact matches

Your statement that «Thus it is natural to look at the real world and see whether there is evidence that it behaves in the same way (and it appears to, since model hindcasts of past changes match observations very well)» seems to indicate that you think there will be no changes in ocean circulation or land use trends, nor any subsequent changes in cloud responses thereto or other atmospheric circulation.

Our general circulation model simulations, which take into account the recently observed widespread occurrence of vertically extended atmospheric brown clouds over the Indian Ocean and Asia3, suggest that atmospheric brown clouds contribute as much as the recent increase in anthropogenic greenhouse gases to regional lower atmospheric warming trends.

«It's important to determine where we believe that some of the recent trends in circulation could potentially be linked with climate change, rather than just natural variability,» Ted Shepherd, an atmospheric scientist at the University of Reading in the U.K., said in an email.

An INTAS - funded research project has been initiated to study the possible trends in snow cover during the last century over Northern Eurasia and the relation between snow cover variability and variations in atmospheric circulation patterns.

Your statement that «Thus it is natural to look at the real world and see whether there is evidence that it behaves in the same way (and it appears to, since model hindcasts of past changes match observations very well)» seems to indicate that you think there will be no changes in ocean circulation or land use trends, nor any subsequent changes in cloud responses thereto or other atmospheric circulation.

Here we analyze a series of climate model experiments along with observational data to show that the recent warming trend in Atlantic sea surface temperature and the corresponding trans - basin displacements of the main atmospheric pressure centers were key drivers of the observed Walker circulation intensification, eastern Pacific cooling, North American rainfall trends and western Pacific sea - level rise.

In spite of recent progress in determining the climatic impacts of the Pacific trade wind acceleration, the cause of this pronounced trend in atmospheric circulation remains unknown.

«A fundamental new trend in atmospheric and ocean circulation patterns in the Pacific Northwest appears to have begun, scientists say, and apparently is expanding its scope beyond Oregon waters... This year for the first time, the effect of the low - oxygen zone is also being seen in coastal waters off Washington,»

Our general circulation model simulations, which take into account the recently observed widespread occurrence of vertically extended atmospheric brown clouds over the Indian Ocean and Asia, suggest that atmospheric brown clouds contribute as much as the recent increase in anthropogenic greenhouse gases to regional lower atmospheric warming trends.

Romanski, J., and S. Hameed, 2015: The impact of trends in the large scale atmospheric circulation on Mediterranean surface turbulent heat fluxes.

Some scientists have sought comfort by noting that extrapolating trends in atmospheric CO2 show that the northern Gulf Stream circulation might not shut down for another 400 years.

Three of these five intervals coincided with multidecadal hemispheric climate - regime shifts, which were characterized by a switch between distinct atmospheric and oceanic circulation patterns, a reversal of NHT trend, and by altered character of ENSO variability.

The causes of the large trends in atmospheric circulation and summer SST are not known.»

Magnusdottir, G., R. Saravanan and C. Deser, 2003: The modelled response of the atmospheric winter circulation to North Atlantic SST and sea - ice anomalies corresponding to multidecadal trends.

«To conclude, modeled atmospheric circulation and SST trends over the past century are significantly different from the observed ones.

Although the NAO is the dominant pattern of atmospheric circulation variability, accounting for about half of the total winter SLP variance on both interannual and multi-decadal time scales, other large - scale structures of internal circulation variability will also undoubtedly contribute to uncertainty in future climate trends.

These NAO - induced «book - ends» of future climate trends are very similar to those depicted in the individual simulations shown earlier (Fig. 1), but instead of case studies, they are based on the dominant structure of internal atmospheric circulation variability across all 40 ensemble members superimposed upon the forced response.

This study has highlighted the role of internal variability of the NAO, the leading mode of atmospheric circulation variability over the Atlantic / European sector, on winter (December - March) surface air temperature (SAT) and precipitation (P) trends over the next 30 years (and the next 50 years: see Supplemental Materials) using a new 40 - member ensemble of climate change simulations with CESM1.

These different SAT trends occur despite the fact that both simulations were subject to the identical radiative forcing and were conducted with the same model, highlighting the role of internal atmospheric circulation variability in any single model run.

Such P trends are consistent with the anomalous large - scale atmospheric circulation changes.

They concluded, «ocean pH does not simply reflect atmospheric CO2 trends but rather that circulation / biogeochemical changes account for > 90 % of pH variability in the Sargasso Sea and more variability in the last century than would be predicted from anthropogenic uptake of CO2 alone.»

Thus, at least for the spring season, it seems unnecessary to invoke processes other than the atmospheric circulation to explain trends in Antarctic sea ice.

Importantly, the region of temperature trends explained by trends in sea ice and the atmospheric circulation is the region of trends that are statistically significant.

Finally, atmospheric model simulations with prescribed sea surface temperatures (SSTs) illuminate the role of SST trends in forcing the observed circulation trends.

Most of the circulation trend projects onto the two Pacific South American (PSA) modes of atmospheric circulation variability, while the Southern Annular Mode lacks a positive trend in spring that would otherwise cause a cooling tendency.

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.

While other studies have had limited success in quantitatively explaining Antarctic sea ice trends in terms of the atmospheric circulation (Liu et al. 2004; Stammerjohn et al. 2008), our congruency analysis of sea ice trends with the atmospheric circulation (Figs. 7b, 8a) explains nearly all of the negative sea ice trend in the Amundsen Sea and a significant portion of the negative trends in the Bellingshausen Sea and positive trends in the Ross Sea.

Addressing these questions requires investigation of the sea ice - air temperature relationship as well as revisiting the relationships of Antarctic temperature and sea ice anomalies with variability and trends in the extratropical atmospheric circulation.

Some cooling on the EAIS also appears to be connected with the ABS sea ice trends, likely through organized patterns of atmospheric circulation changes.

c Residual trends, not explained by the two modes of atmospheric circulation

However, there is also an emerging signal of overall Arctic sea ice decline since 1979 in both winter and summer that is not directly attributable to a trend in the overlying atmospheric circulation.»

This spatial pattern has been attributed to a trend towards the positive phase of the Southern Annular Mode (SAM)(e.g. Thompson and Solomon 2002; Marshall 2007), the leading mode of variability in the extra-tropical atmospheric circulation, characterized by atmospheric pressure anomalies of opposite sign between the polar latitudes and the mid-latitudes.

In both the tropics and extratropics, it is difficult to discern significant long - term trends in the patterns of climate variability from natural variability, never mind abrupt (threshold) changes in the atmospheric circulation.

We see similar excursions from the trend line in our modelling, so we feel that there is an actual variability here that is associated with year - to - year changes in the atmospheric circulation.

Full text here: Contribution of changes in atmospheric circulation patterns to extreme temperature trends.