@article{efb68cb3b42241a59195cf27bc2ea190,
title = "Projected Changes in Summertime Circulation Patterns Imply Increased Drought Risk for the South-Central United States",
abstract = "Historically, extreme hot, dry summers over the South-Central (SC) United States are dominated by an isolated dome of high pressure centered over the region. Applying self-organizing map techniques to North American Regional Reanalysis reanalysis and historical and future Coupled Model Intercomparison Project version 5 (CMIP5) simulations, we find that as the world warms, this type of high-pressure system is likely to become stronger and more frequent—even after removing the effect of surface warming on the expansion of the lower atmosphere. These projected changes appear to be related to self-reinforcing ocean-atmosphere interactions in a warming world. Specifically, intensified easterly winds over the Atlantic and Gulf of Mexico drive an increase in the meridional sea surface temperature gradient due to oceanic Ekman transport, which further enhances the ridge of high pressure extending across the SC United States: a dynamical relationship that increases confidence in regional projections of summer drought risk over the SC United States.",
keywords = "CMIP5 models, NASH, drought, sea surface temperature, self-organizing map",
author = "Ryu, {Jung Hee} and Katharine Hayhoe and Kang, {Song Lak}",
note = "Funding Information: This research was supported by USGS award G15AP00137. The North American Regional Reanalysis (NARR) data set is available at https://www.esrl. noaa.gov/psd/data/gridded/data.narr. html, and CMIP5 model outputs from historical forcing and future projections (RCP4.5 and RCP8.5) are available at https://esgf-node.llnl.gov/projects/esgf-llnl/. We used the monthly SST data from the National Oceanic and Atmospheric Administration (NOAA) Optimum Interpolation (OI) SST V2 available at http://www.esrl.noaa.gov/ psd/data/gridded/data.noaa.oisst.v2. html. CRU TS4.01 data set for 3-month precipitation and potential evapotranspiration is available at https://crudata.uea.ac.uk/cru/data/hrg/ cru_ts_4.01/. R package to calculate SPEI is available at https://cran.r-project.org/ web/packages/SPEI/. R package to calculate SOM is available at https:// cran.r-project.org/web/packages/som/ index.html. Funding Information: This research was supported by USGS award G15AP00137. The North American Regional Reanalysis (NARR) data set is available at https://www.esrl.noaa.gov/psd/data/gridded/data.narr.html, and CMIP5 model outputs from historical forcing and future projections (RCP4.5 and RCP8.5) are available at https://esgf-node.llnl.gov/projects/esgf-llnl/. We used the monthly SST data from the National Oceanic and Atmospheric Administration (NOAA) Optimum Interpolation (OI) SST V2 available at http://www.esrl.noaa.gov/psd/data/gridded/data.noaa.oisst.v2.html. CRU TS4.01 data set for 3-month precipitation and potential evapotranspiration is available at https://crudata.uea.ac.uk/cru/data/hrg/cru_ts_4.01/. R package to calculate SPEI is available at https://cran.r-project.org/web/packages/SPEI/. R package to calculate SOM is available at https://cran.r-project.org/web/packages/som/index.html. Publisher Copyright: {\textcopyright}2018. American Geophysical Union. All Rights Reserved.",
year = "2018",
month = oct,
day = "28",
doi = "10.1029/2018GL080593",
language = "English",
volume = "45",
pages = "11,447--11,455",
journal = "Geophysical Research Letters",
issn = "0094-8276",
number = "20",
}