Abstract
In this paper, we applied the Empirical Orthogonal Function (EOF) analysis on a drought index expressed as consecutive dry days (CDD) to identify the drought variability in western United States. Based on the EOF analysis, correlation maps were generated between the leading principle component (PC) of seasonal CDD and sea surface temperature (SST) anomalies to explore the dynamic context of the leading modes in CDD. The EOF analysis indicates that the spatiotemporal pattern of winter CDD is related to an integrated impact from El Niño–Southern Oscillation (ENSO), Pacific Decadal Oscillation (PDO), and Atlantic Multi-decadal Oscillation (AMO), while summer CDD is mainly controlled by PDO phases. We also calculated seasonal CDD anomalies during selected climatic phases to further evaluate the impacts of large-scale oceanic oscillation on the spatial pattern of droughts. We found that AMO+/PDO− will contribute to a consistent drought condition during the winter in the western United States. El Niño will bring a dry winter to the northern part of western United States while La Niña will bring a dry winter to the southern part. During El Niño years, the drought center changes with the type of El Niño events. Considering the future states of the examined ocean oscillations, we suggest possible drier than normal conditions in the western United States for upcoming decades, and moreover, an intensified drought for the coast areas of the north Pacific region and upper Mississippi River Basin.
Highlights
Drought, generally known as periods of short-term or prolonged deficiency in precipitation, is a recurring natural disaster that has considerable impacts on natural habitats, ecosystems, and many economic and social sectors worldwide [1]
consecutive dry days (CDD) and is related to anpattern integrated of El Niño–Southern Oscillation (ENSO), inWe thefound western how this couldimpact be impacted by Pacific Decadal Oscillation (PDO), large and is mainly controlled by
Our results indicated that scale ocean oscillations
Summary
Generally known as periods of short-term or prolonged deficiency in precipitation, is a recurring natural disaster that has considerable impacts on natural habitats, ecosystems, and many economic and social sectors worldwide [1]. The western United States, due to its geographic and climatological characteristics, rapidly changing social dynamics, and pressure from an expanding population, is vulnerable to severe and sustained droughts [2,3,4]. Proxy climate indicators, such as lake–ocean sediments and tree rings, indicate that the western U.S and surrounding regions have suffered from severe droughts, posing threats to social and ecological systems [5,6,7,8,9]. The prediction of future drought is possible if the teleconnections between droughts and natural oscillations are thoroughly
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
