Associations of multi-decadal sea-surface temperature variability with US drought

Abstract

Recent research suggests a link between drought occurrence in the conterminous United States (US) and sea surface temperature (SST) variability in both the tropical Pacific and North Atlantic Oceans on decadal to multidecadal (D2M) time scales. Results show that the Atlantic Multidecadal Oscillation (AMO) is the most consistent indicator of D2M drought variability in the conterminous US during the 20th century, but during the 19th century the tropical Pacific is a more consistent indicator of D2 M drought. The interaction between El Nin˜o-Southern Oscillation (ENSO) and the AMO explain a large part of the D2M drought variability in the conterminous US. More modeling studies are needed to reveal possible mechanisms linking low-frequency ENSO variability and the AMO with drought in the conterminous US. r

Ecology and the ratchet of events: Climate variability, niche dimensions, and species distributions

“…Moreover, extreme climate anomalies are not randomly distributed in time. Instead, unusually dry years cluster to form long-term droughts, with wet years aggregating to form pluvial periods (39).…”

“…For example, the subdecadal El Niño-Southern Oscillation (ENSO) in the tropical Pacific interacts with the Pacific Decadal Oscillation poleward of 20°and the Atlantic Multidecadal Oscillation (AMO) to influence continental climate over much of North America (39,40). Climate impacts of interannual ENSO variability may be contingent on the state of the decadal-tomultidecal AMO and PDO variability.…”

Decadal predictability of soil water, vegetation, and wildfire frequency over North America

“…Fire risk is evaluated from the histogram ratio of wet (solid) or dry (broken) conditions to the entire period (gray in top panels) the anthropogenic component and the aerosol forcing, which were neglected in our study, may induce additional predictable trends. Furthermore, SST variability (Seager et al 2005(Seager et al , 2008Meehl and Hu 2006;McCabe et al 2008), as well as external forcings (Dai 2011(Dai , 2013Coats et al 2013), may contribute to the low frequency variability and potential decadal-scale predictability of hydroclimate variability over North America. Other factors that will affect the forecast skill of a realistically initialized CESM include ensemble size, internal model biases, initialization method, and the low resolution adopted here.…”

“…US and leading modes of sea surface temperature (SST) anomalies, such as the Pacific Decadal Oscillation (PDO), the Atlantic Multidecadal Oscillation (AMO) (Seager et al 2005(Seager et al , 2008Meehl and Hu 2006;Sheffield and Wood 2008;Schubert et al 2009;Famiglietti et al 2011;Dai 2011;Hu et al 2013), and ENSO (Kanamitsu et al 2003;Barlow et al 2001;Kumar 2002, 2004;McCabe et al 2008;Dai 2013). To determine the relation (not the causality) between SST and simulated decadal hydroclimate variability in the CESM CTL run, we calculated the correlations and regressions of the SST and sea level pressure (SLP) anomaly fields with the leading principal Correlation coefficients are calculated using annual mean data for the first EOF mode of annual precipitation, 10-year running mean data for the low-frequency precipitation, and 10-year running mean data leading with 5-year for the total water storage.…”

GCM projections for the Pacific Decadal Oscillation under greenhouse forcing for the early 21st century

“…As a look-up aid, the plus or minus sign over the Yukon Territory, Canada, denotes whether a particular GCM run or average run showed a positive PDO shift (+) or negative PDO shift (−) in the 21st century as in Table III. This figure is available in colour online at wileyonlinelibrary.com/journal/joc are associated with a hemispheric SLP pattern that shows opposite atmospheric pressure anomalies over the North Pacific and North Atlantic Oceans (see review in McCabe et al, 2008). This North Pacific SLP pattern is amplified through atmosphere-ocean interactions and the SST pattern appears to be the PDO.…”