Climatology of Persistent Positive Temperature Anomalies for the Contiguous United States (1950-1995)

Choi, Jongnam; Meentemeyer, Vernon

doi:10.2747/0272-3646.23.3.175

Cited by 5 publications

(3 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The 500 mbar winds also suggest a shift toward increased anticyclonic circulation anomalies in the midtroposphere over much of the United States during the 21st century (Figure 7). Anticyclonic anomalies in the midtroposphere have been linked to 20th century hot‐and‐dry events over the central United States [ Chang and Wallace , 1987; Chen and Newman , 1998; Choi and Meentemeyer , 2002; Hong and Kalnay , 2002]. The 500 mbar anticyclonic circulation anomalies that occur over the central United States in our 21st century ensemble experiment are associated with decreases in precipitation, soil moisture, evapotranspiration and relative humidity, along with increases in incident and net surface shortwave flux and surface sensible heat flux (Figure 5 and 7).…”

Section: Resultsmentioning

confidence: 89%

Transient regional climate change: Analysis of the summer climate response in a high-resolution, century-scale ensemble experiment over the continental United States

2011

View full text Add to dashboard Cite

Integrating the potential for climate change impacts into policy and planning decisions requires quantification of the emergence of sub-regional climate changes that could occur in response to transient changes in global radiative forcing. Here we report results from a high-resolution, century-scale, ensemble simulation of climate in the United States, forced by atmospheric constituent concentrations from the Special Report on Emissions Scenarios (SRES) A1B scenario. We find that 21st century summer warming permanently emerges beyond the baseline decadal-scale variability prior to 2020 over most areas of the continental U.S. Permanent emergence beyond the baseline annual-scale variability shows much greater spatial heterogeneity, with emergence occurring prior to 2030 over areas of the southwestern U.S., but not prior to the end of the 21st century over much of the southcentral and southeastern U.S. The pattern of emergence of robust summer warming contrasts with the pattern of summer warming magnitude, which is greatest over the central U.S. and smallest over the western U.S. In addition to stronger warming, the central U.S. also exhibits stronger coupling of changes in surface air temperature, precipitation, and moisture and energy fluxes, along with changes in atmospheric circulation towards increased anticylonic anomalies in the mid-troposphere and a poleward shift in the mid-latitude jet aloft. However, as a fraction of the baseline variability, the transient warming over the central U.S. is smaller than the warming over the southwestern or northeastern U.S., delaying the emergence of the warming signal over the central U.S. Our comparisons with observations and the Coupled Model Intercomparison Project Phase 3 (CMIP3) ensemble of global climate model experiments suggest that near-term global warming is likely to cause robust sub-regional-scale warming over areas that exhibit relatively little baseline variability. In contrast, where there is greater variability in the baseline climate dynamics, there can be greater variability in the response to elevated greenhouse forcing, decreasing the robustness of the transient warming signal.

show abstract

Section: Resultsmentioning

confidence: 89%

Transient regional climate change: Analysis of the summer climate response in a high-resolution, century-scale ensemble experiment over the continental United States

2011

View full text Add to dashboard Cite

show abstract

“…The color bars below the panels are in K. see for example Kunkel et al (1996), Huth et al (2000), Palecki et al (2001), Burt (2004), and Khaliq et al (2005). A comprehensive analysis of heat waves in the United States for the period 1950-95 has been presented by Choi and Meentemeyer (2002). A comprehensive analysis of heat waves in the United States for the period 1950-95 has been presented by Choi and Meentemeyer (2002).…”

Section: Daily Heat Wavesmentioning

confidence: 99%

“…Results are for the summer months of June, July, and August only. In their observational analysis, Choi and Meentemeyer (2002) note a maximum duration heat wave occurrence of 41 days in Texas, where values were one standard deviation (ϳ4 K) above normal. 9, with extreme anomalies of up to 12 K. For this particular example the largest number of successive days meeting the 4-K criterion was 20, which occurred in model year 4470 in Fig.…”

Section: Daily Heat Wavesmentioning

confidence: 99%

A Climatology of Heat Waves from a Multimillennial Simulation

Hunt

2007

Journal of Climate

View full text Add to dashboard Cite

A 10 000-yr unforced simulation with the Commonwealth Scientific and Industrial Research Organisation (CSIRO) Mark 2 coupled global climatic model has been used to investigate the occurrence of heat waves over the globe. Results are presented for both seasonal (summer mean) and daily heat waves. Geographical distributions of the occurrence rates of these heat waves are shown for various magnitudes of surface temperature anomalies. The heat waves have specific geographical preferences with regions where relatively frequent, intense, and long-lasting heat waves occur. Time series over all 10 000 yr of the heat waves for the selected model grid boxes illustrate the differing temporal variabilities at these locations, as well as identifying the occurrences of extreme heat waves. To this end, the observed European heat wave of 2003 was simulated remarkably well in its overall characteristics; it occurs once in this simulation. Heat waves for various continental locations are shown to occur as isolated spatial and temporal events, and not as part of larger-scale systems over continental-size domains, suggesting stochastic forcing as a contributor to the initiation of the heat waves. Regional plots of selected heat waves at monthly intervals illustrated the considerable spatial variability, progression, and variation in the intensity of the heat waves. Comparison of year-long daily surface temperature anomalies for heat-wave years for simulated and observed conditions at individual model grid boxes indicated substantial agreement, while spatial plots permitted the progress of a short-term heat wave over the United States to be followed. Multidecadal time series plots of intense heat waves also showed basic similarities between the simulation and observations, despite the brevity of the latter. The simulated time series suggest that more extreme heat waves than currently are observed, owing to the brevity of the observations, may be a possibility as a consequence solely of natural variability. An examination of the physical processes associated with a heat wave showed mutually consistent climatic relationships, such that a heat wave was associated with reduced rainfall and consequently reduced soil moisture content, evaporation, and cloud cover, and increased insolation at the surface. These combined changes created the surface temperature increase intrinsic to the heat wave. All heat waves examined for different regions experienced negative rainfall anomalies prior to a heat wave. The cause of these rainfall anomalies was not readily apparent. While an ENSO influence on heat waves is shown to exist in the simulation, not all ENSO events produce heat waves, suggesting that stochastic influences may determine when a major heat wave occurs in conjunction with these events. The limitations of the adequacy of the model ENSO may, however, have had an influence in this regard.

show abstract

A Model Study of Heat Waves over North America: Meteorological Aspects and Projections for the Twenty-First Century

2012

View full text Add to dashboard Cite

The characteristics of summertime heat waves in North America are examined using reanalysis data and simulations by two general circulation models with horizontal resolution of 50 and 200 km. Several “key regions” with spatially coherent and high amplitude fluctuations in daily surface air temperature are identified. The typical synoptic features accompanying warm episodes in these regions are described. The averaged intensity, duration, and frequency of occurrence of the heat waves in various key regions, as simulated in the two models for twentieth-century climate, are in general agreement with the results based on reanalysis data. The impact of climate change on the heat wave characteristics in various key regions is assessed by contrasting model runs based on a scenario for the twenty-first century with those for the twentieth century. Both models indicate considerable increases in the duration and frequency of heat wave episodes, and in number of heat wave days per year, during the twenty-first century. The duration and frequency statistics of the heat waves in the mid-twenty-first century, as generated by the model with 50-km resolution, can be reproduced by adding the projected warming trend to the daily temperature data for the late twentieth century, and then recomputing these statistics. The detailed evolution of the averaged intensity, duration, and frequency of the heat waves through individual decades of the twentieth and twenty-first centuries, as simulated and projected by the model with 200-km resolution, indicates that the upward trend in these heat wave measures should become apparent in the early decades of the twenty-first century.

show abstract

Climatology of Persistent Positive Temperature Anomalies for the Contiguous United States (1950-1995)

Cited by 5 publications

References 20 publications

Transient regional climate change: Analysis of the summer climate response in a high-resolution, century-scale ensemble experiment over the continental United States

Transient regional climate change: Analysis of the summer climate response in a high-resolution, century-scale ensemble experiment over the continental United States

A Climatology of Heat Waves from a Multimillennial Simulation

A Model Study of Heat Waves over North America: Meteorological Aspects and Projections for the Twenty-First Century

Contact Info

Product

Resources

About