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.
Not exact matches
They were in less agreement about how intense rain or snow will be when it does fall, although there is general consensus among
models that the most
extreme precipitation will become more frequent.
While the
models do not reliably track individual
extreme weather events, they do reproduce the jet stream patterns and temperature scenarios that in the real world lead to torrential rain for days, weeks of broiling sun and absence of
precipitation.
Computer
models showed a reduction in what Edwards called «
extreme precipitation events» in the fall season in western South Dakota when compared to climate conditions in the 1800s.
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.
Daniel Swain and colleagues
model how the frequency of these rapid, year - to - year transitions from
extreme dry to wet conditions — which they dub «
precipitation whiplash events» — may change in California's future as a consequence of man - made warming.
Climate
model projections show a warmer Montana in the future, with mixed changes in
precipitation, more
extreme events, and mixed certainty on upcoming drought.
Durman, C.F., et al., 2001: A comparison of
extreme European daily
precipitation simulated by a global
model and regional climate
model for present and future climates.
His work mainly focuses on remote sensing of
precipitation, hydrologic applications, and the analysis of
extreme weather and climatic events using observation and
models.
Using high - resolution
modeling with theoretical and statistical analysis, researchers revealed a direct link between in - cloud processes and the frequency of
precipitation extremes.
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.
Mean temperature, mean monthly
precipitation, frequency of hot / cold days / nights, and indices of
extreme precipitation are all estimated for each country based on observed and
modeled data.
Because of the limited availability of daily observations, however, most previous studies have examined only the potential detectability of changes in
extreme precipitation through
model —
model comparisons (12 — 15).
Changes in
extreme precipitation projected by
models, and thus the impacts of future changes in
extreme precipitation, may be underestimated because
models seem to underestimate the observed increase in heavy
precipitation with warming.
At the tail end of the full paper, capping a paragraph about a weak spot in the analysis — that the observed trend in
extreme precipitation events exceeds what is produced by various climate
models — comes a sentence about uncertainties:
Without El Niño and La Niña feeding into the climate
model, the frequency of
extreme precipitation in California stayed constant for the simulation's century and a half.
2: Our Changing Climate, Key Message 5).2 Regional climate
models (RCMs) using the same emissions scenario also project increased spring
precipitation (9 % in 2041 - 2062 relative to 1979 - 2000) and decreased summer
precipitation (by an average of about 8 % in 2041 - 2062 relative to 1979 - 2000) particularly in the southern portions of the Midwest.12 Increases in the frequency and intensity of
extreme precipitation are projected across the entire region in both GCM and RCM simulations (Figure 18.6), and these increases are generally larger than the projected changes in average
precipitation.12, 2
Precipitation extremes and their potential future changes were predicted using six - member ensembles of general circulation
models (GCMs) from the Coupled
Model Intercomparison Project Phase 5 (CMIP5).
Given the different responses of high - and low - resolution
models to CO2 forcing, the authors emphasize the importance of
model choice for any study of
extreme precipitation.
For example, the two
models with the highest resolution (FLOR and HiFLOR) show increased
extreme precipitation during the Atlantic hurricane season in the U.S. southeast.
Results show that higher - resolution
models significantly improve the simulation of mean
precipitation, the distribution of
precipitation, and spatial patterns, intensity and seasonality of
precipitation extremes.
In response to 2xCO2 forcing, all
models show a mean intensification of
precipitation extremes, of approximately 3 - 4 % / K.
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.
This study employed three newly developed global coupled climate
models to study the impact of horizontal atmospheric
model resolution (tile size) on
precipitation extremes.
This requires considerable integrity in the
model's ability to simulate both, but
models typically have great difficulty in simulating
extremes well (Lin et al. 2006; Kharin et al. 2007) especially throughout the tropics for
precipitation.
More accurate and reliable
precipitation data would be invaluable, not only for the study of climate trends and variability, but also as inputs to hydrological and ecological
models and for
model validation, characterization of
extreme events, and flood and drought forecasting.
The US CLIVAR
Extremes Working Group was formed to evaluate whether current climate models produce extremes for the right reasons and whether they can be used for predicting and projecting short - term extremes in temperature and precipitation over North
Extremes Working Group was formed to evaluate whether current climate
models produce
extremes for the right reasons and whether they can be used for predicting and projecting short - term extremes in temperature and precipitation over North
extremes for the right reasons and whether they can be used for predicting and projecting short - term
extremes in temperature and precipitation over North
extremes in temperature and
precipitation over North America.
Reviewing the first one in 2000, myself and Chip Knappenberger discovered that the science team just happened to choose the two most
extreme models (for temperature and
precipitation) out of the 14 they considered.
Regional climate simulations, driven by two «well performing» dynamically downscaled IPCC
models, also shows an amplification of historical summer temperature and
precipitation extremes is occurring in conjunction with the Pacific sea surface temperature influence on US regional climate.
Output from global circulation
models indicates that climate variability will continue to be an important characteristic of the region in the future [52], but that climate change may increase the risk of
extreme climatic events such as multi-decade droughts and
extreme winter
precipitation [53], [54].
Recently developed convection - permitting
models better simulate
extreme precipitation, but simulations are not yet widely available due to their computational cost, and they have their own uncertainties.
Using an ensemble of four high resolution (~ 25 km) regional climate
models, this study analyses the future (2021 - 2050) spatial distribution of seasonal temperature and
precipitation extremes in the Ganges river basin based on the SRES A1B emissions scenario.
the
model does not simulate any dependence of Northern England
precipitation on the state of El Niño, with a correlation coefficient of r = 0.01 and no visual indications that
extreme events behave differently than the mean.
Another study examined the potential flood damage impacts of changes in
extreme precipitation events using the Canadian Climate Centre
model and the IS92a emissions scenario for the metropolitan Boston area in the north - eastern USA (Kirshen et al., 2005b).
PDRMIP investigates the role of various drivers of climate change for mean and
extreme precipitation changes, based on multiple climate
model output and energy budget analyses.
This demonstrates the importance of
model physics for teleconnections to
extreme precipitation.
For terrestrial British Columbia,
precipitation averages and
extremes can be simulated more accurately within individual regions by using gridded downscaling to increase the resolution of both global and regional climate
models.
In this study, evidence for a nonlinear association between ENSO and
precipitation extremes is reassessed by fitting stationary and linear / nonlinear GEV regression
models, with the Niño3.4 index as a covariate, to 1 -, 5 -, and 10 - day extended winter
precipitation maxima.
CAS = Commission for Atmospheric Sciences CMDP = Climate Metrics and Diagnostic Panel CMIP = Coupled
Model Intercomparison Project DAOS = Working Group on Data Assimilation and Observing Systems GASS = Global Atmospheric System Studies panel GEWEX = Global Energy and Water Cycle Experiment GLASS = Global Land - Atmosphere System Studies panel GOV = Global Ocean Data Assimilation Experiment (GODAE) Ocean View JWGFVR = Joint Working Group on Forecast Verification Research MJO - TF = Madden - Julian Oscillation Task Force PDEF = Working Group on Predictability, Dynamics and Ensemble Forecasting PPP = Polar Prediction Project QPF = Quantitative
precipitation forecast S2S = Subseasonal to Seasonal Prediction Project SPARC = Stratospheric Processes and their Role in Climate TC = Tropical cyclone WCRP = World Climate Research Programme WCRP Grand Science Challenges • Climate
Extremes • Clouds, Circulation and Climate Sensitivity • Melting Ice and Global Consequences • Regional Sea - Ice Change and Coastal Impacts • Water Availability WCRP JSC = Joint Scientific Committee WGCM = Working Group on Coupled
Modelling WGSIP = Working Group on Subseasonal to Interdecadal Prediction WWRP = World Weather Research Programme YOPP = Year of Polar Prediction
Regional Climate
Models projections are used to provide projections of changes in temperature,
precipitation, and indices of
extremes.
For terrestrial British Columbia,
precipitation averages and
extremes can be simulated more accurately within individual regions by using gridded downscaling to increase the resolution of regional climate
models.
While researchers have identified teleconnections between El Niño - Southern Oscillation (ENSO) and extended winter
precipitation extremes in North America using generalized
extreme value (GEV)
models, the regional form of the statistical relationship remains an open question.
This report discusses our current understanding of the mechanisms that link declines in Arctic sea ice cover, loss of high - latitude snow cover, changes in Arctic - region energy fluxes, atmospheric circulation patterns, and the occurrence of
extreme weather events; possible implications of more severe loss of summer Arctic sea ice upon weather patterns at lower latitudes; major gaps in our understanding, and observational and / or
modeling efforts that are needed to fill those gaps; and current opportunities and limitations for using Arctic sea ice predictions to assess the risk of temperature /
precipitation anomalies and
extreme weather events over northern continents.
The first (2000) Assessment used the two most
extreme models of the 14 considered for temperature and
precipitation.
We are not aware of any other study that has documented the impact of the
precipitation simulation imperfections on GCMs» predictions of surface air temperature, but the ability of such flawed
models to predict global warming and its
extremes could be compromised.
Bracken C., B. Rajagopalan, L. Cheng, W. Kleiber and S. Gangopadhyay (August 2016): Spatial Bayesian hierarchical
modeling of
precipitation extremes over a large domain.
Further investigation using high - resolution
modeling approaches that better resolve the boundary conditions and fine - scale physical processes (44 ⇓ — 46) and / or using analyses that focus on the underlying large - scale climate dynamics of individual
extreme events (8) could help to overcome the limitations of simulated
precipitation and temperature in the current generation of global climate
models.
Future change of
precipitation extremes in Europe: Intercomparison of scenarios from regional climate
models.
Although the global
models have improved over time (Chapter 8), they still have limitations that affect the simulation of
extreme events in terms of spatial resolution, simulation errors, and parametrizations that must represent processes that can not yet be included explicitly in the
models, particularly dealing with clouds and
precipitation (Meehl et al., 2000d).
Understanding and
modeling the fundamental processes that govern the large
precipitation variability and
extremes in the western U.S. is a critical test for the ability of climate
models to predict the regional water cycle, including floods and droughts.