The continuum of drought in southwestern North America
Citable URI
https://hdl.handle.net/1912/10623As published
https://doi.org/10.1175/JCLI-D-18-0010.1DOI
10.1175/JCLI-D-18-0010.1Keyword
Atmosphere-ocean interaction; Drought; Paleoclimate; Ensembles; General circulation models; Climate variabilityAbstract
Drought has severe consequences for humans and their environment, yet we have a limited understanding of the drivers of drought across the full range of time scales on which it occurs. Here, the atmosphere and ocean conditions that drive this continuum of drought variability in southwestern North America (SWNA) are studied using the latest observationally based products, paleoclimate reconstructions, and state-of-the-art Earth system model simulations of the last millennium. A novel application of the self-organizing maps (SOM) methodology allows for a visualization of the continuum of climate states coinciding with thousands of droughts of varying lengths in last millennium simulations from the Community Earth System Model (CESM), the Goddard Institute for Space Studies Model E2-R (GISS E2-R), and eight other members from phase 5 of the Coupled Model Intercomparison Project (CMIP5). It is found that most droughts are associated with a cool Pacific decadal oscillation (PDO) pattern, but persistent droughts can coincide with a variety of ocean–atmosphere states, including time periods showing a warm PDO or weak ocean–atmosphere anomalies. Many CMIP5 models simulate similar SWNA teleconnection patterns, but the SOM analysis demonstrates that models simulate different continuums of ocean–atmosphere states coinciding with droughts of different lengths, suggesting fundamental differences in their drought dynamics. These findings have important implications for our understanding and simulation of the drivers of persistent drought, and for their potential predictability.
Description
Author Posting. © American Meteorological Society, 2018. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Climate 31 (2018): 8627-8643, doi:10.1175/JCLI-D-18-0010.1.
Collections
Suggested Citation
Journal of Climate 31 (2018): 8627-8643Related items
Showing items related by title, author, creator and subject.
-
Duration and severity of Medieval drought in the Lake Tahoe Basin
Kleppe, J. A.; Brothers, Daniel S.; Kent, Graham M.; Biondi, F.; Jensen, S.; Driscoll, Neal W. (Elsevier B.V., 2001-09-16)Droughts in the western U.S. in the past 200 years are small compared to several megadroughts that occurred during Medieval times. We reconstruct duration and magnitude of extreme droughts in the northern Sierra Nevada ... -
Early assessment of seasonal forage availability for mitigating the impact of drought on East African pastoralists
Vrieling, Anton; Meroni, Michele; Mude, Andrew G.; Chantarat, Sommarat; Ummenhofer, Caroline C.; de Bie, Kees (C.A.J.M.) (2015-11)Pastoralist households across East Africa face major livestock losses during drought periods that can cause persistent poverty. For Kenya and southern Ethiopia, an existing index insurance scheme aims to reduce the adverse ... -
Can Australian multiyear droughts and wet spells be generated in the absence of oceanic variability?
Taschetto, Andrea S.; Sen Gupta, Alexander; Ummenhofer, Caroline C.; England, Matthew H. (American Meteorological Society, 2016-08-19)Anomalous conditions in the tropical oceans, such as those related to El Niño–Southern Oscillation and the Indian Ocean dipole, have been previously blamed for extended droughts and wet periods in Australia. Yet the extent ...