Atmospheric rivers as drought busters on the US West Coast

TitleAtmospheric rivers as drought busters on the US West Coast
Publication TypeJournal Article
Year of Publication2013
AuthorsDettinger MD
JournalJournal of Hydrometeorology
Volume14
Pagination1721-1732
Date Published2013/12
Type of ArticleArticle
ISBN Number1525-755X
Accession NumberWOS:000327254200003
Keywordscalifornia; drought; environments; Extreme events; floods; North America; precipitation; satellite; severity index; Storm; united-states
Abstract

Atmospheric rivers (ARs) have, in recent years, been recognized as the cause of the large majority of major floods in rivers all along the U.S. West Coast and as the source of 30%-50% of all precipitation in the same region. The present study surveys the frequency with which ARs have played a critical role as a common cause of the end of droughts on the West Coast. This question was based on the observation that, in most cases, droughts end abruptly as a result of the arrival of an especially wet month or, more exactly, a few very large storms. This observation is documented using both Palmer Drought Severity Index and 6-month Standardized Precipitation Index measures of drought occurrence for climate divisions across the conterminous United States from 1895 to 2010. When the individual storm sequences that contributed most to the wet months that broke historical West Coast droughts from 1950 to 2010 were evaluated, 33%-74% of droughts were broken by the arrival of landfalling AR storms. In the Pacific Northwest, 60%-74% of all persistent drought endings have been brought about by the arrival of AR storms. In California, about 33%-40% of all persistent drought endings have been brought about by landfalling AR storms, with more localized low pressure systems responsible for many of the remaining drought breaks.

DOI10.1175/jhm-d-13-02.1
Short TitleJ. Hydrometeorol.
Integrated Research Themes: 
Student Publication: 
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