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Title: US daily temperature records past, present, and future

Here, the observed temperature extremes over the continental United States can be represented by the ratio of daily record high temperatures to daily record low minimum temperatures, and this ratio has increased to a value of about 2 to 1, averaged over the first decade of the 21st century, albeit with large interannual variability. Two different versions of a global coupled climate model (CCSM4), as well as 23 other coupled model intercomparison project phase 5 (CMIP5) models, show larger values of this ratio than observations, mainly as a result of greater numbers of record highs since the 1980s compared with observations. This is partly because of the “warm 1930s” in the observations, which made it more difficult to set record highs later in the century, and partly because of a trend toward less rainfall and reduced evapotranspiration in the model versions compared with observations. We compute future projections of this ratio on the basis of its estimated dependence on mean temperature increase, which we find robustly at play in both observations and simulations. The use of this relation also has the advantage of removing dependence of a projection on a specific scenario. An empirical projection of the ratio of recordmore » highs to record lows is obtained from the nonlinear relationship in observations from 1930 to 2015, thus correcting downward the likely biased future projections of the model. For example, for a 3 °C warming in US temperatures, the ratio of record highs to lows is projected to be ~15 ± 8 compared to the present average ratio of just over 2.« less
Authors:
 [1] ;  [2] ;  [3]
  1. National Center for Atmospheric Research, Boulder, CO (United States); Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)
  2. National Center for Atmospheric Research, Boulder, CO (United States)
  3. Climate Central, Princeton, NJ (United States)
Publication Date:
Grant/Contract Number:
FC02-97ER62402; AC05-00OR22725; Cooperative Agreement # FC02-97ER62402; UCAR Cooperative Agreement
Type:
Published Article
Journal Name:
Proceedings of the National Academy of Sciences of the United States of America
Additional Journal Information:
Journal Volume: 113; Journal Issue: 49; Journal ID: ISSN 0027-8424
Publisher:
National Academy of Sciences, Washington, DC (United States)
Research Org:
Univ. Corporation for Atmospheric Research, Boulder, CO (United States)
Sponsoring Org:
USDOE Office of Science (SC), Biological and Environmental Research (BER) (SC-23)
Country of Publication:
United States
Language:
English
Subject:
54 ENVIRONMENTAL SCIENCES; temperature extremes; temperature records; global warming; large ensemble
OSTI Identifier:
1333231
Alternate Identifier(s):
OSTI ID: 1464936

Meehl, Gerald A., Tebaldi, Claudia, and Adams-Smith, Dennis. US daily temperature records past, present, and future. United States: N. p., Web. doi:10.1073/pnas.1606117113.
Meehl, Gerald A., Tebaldi, Claudia, & Adams-Smith, Dennis. US daily temperature records past, present, and future. United States. doi:10.1073/pnas.1606117113.
Meehl, Gerald A., Tebaldi, Claudia, and Adams-Smith, Dennis. 2016. "US daily temperature records past, present, and future". United States. doi:10.1073/pnas.1606117113.
@article{osti_1333231,
title = {US daily temperature records past, present, and future},
author = {Meehl, Gerald A. and Tebaldi, Claudia and Adams-Smith, Dennis},
abstractNote = {Here, the observed temperature extremes over the continental United States can be represented by the ratio of daily record high temperatures to daily record low minimum temperatures, and this ratio has increased to a value of about 2 to 1, averaged over the first decade of the 21st century, albeit with large interannual variability. Two different versions of a global coupled climate model (CCSM4), as well as 23 other coupled model intercomparison project phase 5 (CMIP5) models, show larger values of this ratio than observations, mainly as a result of greater numbers of record highs since the 1980s compared with observations. This is partly because of the “warm 1930s” in the observations, which made it more difficult to set record highs later in the century, and partly because of a trend toward less rainfall and reduced evapotranspiration in the model versions compared with observations. We compute future projections of this ratio on the basis of its estimated dependence on mean temperature increase, which we find robustly at play in both observations and simulations. The use of this relation also has the advantage of removing dependence of a projection on a specific scenario. An empirical projection of the ratio of record highs to record lows is obtained from the nonlinear relationship in observations from 1930 to 2015, thus correcting downward the likely biased future projections of the model. For example, for a 3 °C warming in US temperatures, the ratio of record highs to lows is projected to be ~15 ± 8 compared to the present average ratio of just over 2.},
doi = {10.1073/pnas.1606117113},
journal = {Proceedings of the National Academy of Sciences of the United States of America},
number = 49,
volume = 113,
place = {United States},
year = {2016},
month = {11}
}