Influence of the Pacific Decadal Oscillation on Winter Precipitation and Drought during Years of Neutral ENSO in the Western United StatesSource: Weather and Forecasting:;2007:;volume( 022 ):;issue: 001::page 116Author:Goodrich, Gregory B.
DOI: 10.1175/WAF983.1Publisher: American Meteorological Society
Abstract: The influence of the Pacific decadal oscillation (PDO) on important hydroclimatic variables during years of neutral ENSO for 84 climate divisions in the western United States is analyzed from 1925 to 1998. When the 34 neutral ENSO years are split by cold (12 yr) and warm (22 yr) PDOs, the resulting winter precipitation patterns are spatially similar to those that occur during years of La Niña?cold PDO and, to a lesser extent, years of El Niño?warm PDO, respectively, although the characteristic ENSO dipole is not evident. The PDO influence is similar when the winter Palmer drought severity index is analyzed, although the core area of influence moves from the Southwest to the northern Rockies. Correlations between Niño-3.4 SSTs and the hydroclimatic variables reverse sign when the neutral ENSO years are split by PDO phase. The greatest difference between correlations occurs in the characteristic dipole between the Pacific Northwest and the desert Southwest. Since seasonal forecast guidance based on ENSO conditions in the tropical Pacific often yields a forecast of ?equal chances? during years of neutral ENSO, forecasters may be able to improve their forecasts for the southwestern United States depending on if the PDO is known to be in the cold (drier than normal) or warm (wetter than normal) phase. However, this can be difficult to implement considering the current uncertainty of the phase of the PDO.
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contributor author | Goodrich, Gregory B. | |
date accessioned | 2017-06-09T17:35:19Z | |
date available | 2017-06-09T17:35:19Z | |
date copyright | 2007/02/01 | |
date issued | 2007 | |
identifier issn | 0882-8156 | |
identifier other | ams-87671.pdf | |
identifier uri | http://onlinelibrary.yabesh.ir/handle/yetl/4231365 | |
description abstract | The influence of the Pacific decadal oscillation (PDO) on important hydroclimatic variables during years of neutral ENSO for 84 climate divisions in the western United States is analyzed from 1925 to 1998. When the 34 neutral ENSO years are split by cold (12 yr) and warm (22 yr) PDOs, the resulting winter precipitation patterns are spatially similar to those that occur during years of La Niña?cold PDO and, to a lesser extent, years of El Niño?warm PDO, respectively, although the characteristic ENSO dipole is not evident. The PDO influence is similar when the winter Palmer drought severity index is analyzed, although the core area of influence moves from the Southwest to the northern Rockies. Correlations between Niño-3.4 SSTs and the hydroclimatic variables reverse sign when the neutral ENSO years are split by PDO phase. The greatest difference between correlations occurs in the characteristic dipole between the Pacific Northwest and the desert Southwest. Since seasonal forecast guidance based on ENSO conditions in the tropical Pacific often yields a forecast of ?equal chances? during years of neutral ENSO, forecasters may be able to improve their forecasts for the southwestern United States depending on if the PDO is known to be in the cold (drier than normal) or warm (wetter than normal) phase. However, this can be difficult to implement considering the current uncertainty of the phase of the PDO. | |
publisher | American Meteorological Society | |
title | Influence of the Pacific Decadal Oscillation on Winter Precipitation and Drought during Years of Neutral ENSO in the Western United States | |
type | Journal Paper | |
journal volume | 22 | |
journal issue | 1 | |
journal title | Weather and Forecasting | |
identifier doi | 10.1175/WAF983.1 | |
journal fristpage | 116 | |
journal lastpage | 124 | |
tree | Weather and Forecasting:;2007:;volume( 022 ):;issue: 001 | |
contenttype | Fulltext |