Atmospheric dynamics drive most interannual U.S. droughts over the last millennium

M. P. Erb*, J. Emile-Geay, G. J. Hakim, N. Steiger, E. J. Steig

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

13 Scopus citations

Abstract

The American West exemplifies drought-sensitive regions with growing populations. Paleoclimate investigations have documented severe droughts in this region before European settling, with major implications for water management and planning. Here, we leverage paleoclimate data assimilation to reconstruct past climate states, enabling a large-scale multivariate investigation of U.S. drought dynamics over the last millennium. These results confirm that La Niña conditions significantly influence southwest U.S. drought over the past millennium but only account for, by one metric, ~13% of interannual drought variability in that region. Atlantic sea surface temperatures may also contribute a small influence, but unexplained variability suggests a substantial role for internal atmospheric variability. This conclusion is buttressed by analysis of simulations from the Community Earth System Model Last Millennium Ensemble. While greenhouse gases will increase future drought risk, as shown in other work, interannual U.S. drought variations will also be widely influenced by processes internal to the atmosphere.

Original languageAmerican English
Article numbereaay7268
JournalScience advances
Volume6
Issue number32
DOIs
StatePublished - Aug 2020
Externally publishedYes

Bibliographical note

Publisher Copyright:
Copyright © 2020 The Authors,

Fingerprint

Dive into the research topics of 'Atmospheric dynamics drive most interannual U.S. droughts over the last millennium'. Together they form a unique fingerprint.

Cite this