"precipitation extremes" refers to the occurrence of either very heavy rainfall or very dry conditions over a particular area. It highlights the extreme or unusual nature of the precipitation patterns, either in terms of excessive rain leading to floods or long periods without rain leading to droughts.
Full definition
This study employed three newly developed global coupled climate models to study the impact of horizontal atmospheric model resolution (tile size)
on precipitation extremes.
However, the observed precipitation — temperature scaling relationships have been established almost exclusively by linking
precipitation extremes with day - to - day temperature variations.
Overall, scientists say the climatic causes
of precipitation extremes are proving harder to pin down, even as the science of climate change attribution advances rapidly.
O'Gorman, P. A., and T. Schneider, 2009: The physical basis for increases in
precipitation extremes in simulations of 21st - century climate change.
Bracken C., B. Rajagopalan, L. Cheng, W. Kleiber and S. Gangopadhyay (August 2016): Spatial Bayesian hierarchical modeling of
precipitation extremes over a large domain.
«We show that at the present - day warming of 0.85 °C about 18 % of the moderate
daily precipitation extremes over land are attributable to the observed temperature increase since pre-industrial times, which in turn primarily results from human influence,» the research team said.
«Of course, weather is naturally chaotic, and extremes are a normal part of our highly variable UK climate, but globally there has recently been an increase in the incidence of high temperature and
heavy precipitation extremes.
Murdock, T.Q., Cannon, A.J., Sobie, S.R., Veerman, B., Anslow, F. and Zwiers, F.W. (2014) Workshop Primer:
Projected precipitation extremes for Coastal British Columbia.
A programming note: my colleagues and I have just completed a new study on changing
California precipitation extremes, and the associated paper will be released in late April.
The researchers found that there were some improvements in the representation of climate extremes in global climate models, reflected in the closer correspondence of
modelled precipitation extremes and those from simulations, and the decreased spread of values from the newer climate models.
Performance is assessed based on
precipitation extremes indices and results from a generalized extreme value analysis applied to annual precipitation maxima.
«These contradictory points make the connection between the most
recent precipitation extremes and climate change hard to make,» Crouch told Climate Central.
As the 2014 Intergovernmental Panel on Climate Change report notes, models predict that increasing temperature ought to cause
greater precipitation extremes in both directions — both drought and flooding, though there are likely more areas of heavy precipitation.
Such an elevated temperature would amplify temperature and
precipitation extremes enough to make the weather events of recent years look tame in comparison.
The paper, in the new issue of Journal of Climate, is «The resolution dependence of contiguous
U.S. precipitation extremes in response to CO2 forcing» — by Karin van der Wiel of Princeton and colleagues.
Here, we review the evidence and argue that for some types of extreme — notably heatwaves, but
also precipitation extremes — there is now strong evidence linking specific events or an increase in their numbers to the human influence on climate.
There is a minimum model resolution that is needed to capture weather phenomena
generating precipitation extremes, for example for simulating tropical cyclones or precipitation enhancement over mountains.
Following the seasonal evolution of the precipitation climatology, increased
precipitation extremes shift from the Central Great Plains in early summer to the Southwest in late summer.
He presented some climate indices that have been computed from downscaled output and one application, in
which precipitation extremes are studied in the context of highway construction and maintenance.
Extra heat of this kind would also tend to
enhance precipitation extremes — more rain when it does rain and far more intense drought in areas affected by heat and atmospheric ridging.
Hoell A. and L. Cheng (July 2017): Austral summer Southern
Africa precipitation extremes forced by the El Niño - Southern oscillation and the subtropical Indian Ocean dipole.
The recurring theme, though, is difficulties in conducting agriculture: drought in Central America, Pakistan, the western US or Australia, more
monsoonal precipitation extremes in India, and strengthening cyclonic storms add up to a projected net global food deficit at 2.5 C.
QM can inflate the magnitude of relative trends in
precipitation extremes with respect to the raw GCM, often substantially, as compared to DQM and especially QDM.
This article investigates the extent to which quantile mapping algorithms modify global climate model (GCM) trends in mean precipitation and
precipitation extremes indices.
This is addressed by evaluating change in global or large - scale patterns in the frequency or intensity of extremes (e.g., observed widespread intensification
of precipitation extremes attributed to human influence, increase in frequency and intensity of hot extremes) and by event attribution methods.
This post was originally published on this site Today the journal Nature Climate Change published results of a groundbreaking paper that explores the changing character of
precipitation extremes in California.
«In this region where we have known
precipitation extremes, we have been able to detect an increase in precipitation extremes due to a warming climate,» Kapnick said.
«We do see signs of
precipitation extremes increasing in these regions.»
«It is therefore reasonable to expect that
precipitation extremes will continue to intensify,» although how much is still a mystery, largely thanks to an unclear understanding of the atmospheric impact of how tiny flecks of pollution in the atmosphere — known as aerosols to scientists and comprising materials ranging from soot to sulfur dioxide.
In addition to accounting for drought and hurricane winds, the index considers temperature and
precipitation extremes in the U.S..
The report, «Atmospheric Warming and the Amplification of
Precipitation Extremes,» previewed in Science Express this Thursday, August 7, and published in an upcoming issue of Science, found that both observations and models indicated an increase in heavy rainstorms in response to a warmer climate.