Relations between Large-Scale Atmospheric Circulation Patterns and New England River Flow

Abstract

Introduction Research that characterizes and explains the influences of large-scale atmospheric circulation patterns on New England (NE) hydrology has been limited (Bradbury et al. 2002b; Kingston et al. 2006), despite widespread efforts to correlate these atmospheric patterns with local NE climate. Specifically, little research has investigated seasonally-lagged correlations. Such relationships are necessary to produce seasonal streamflow forecasts, a technique that can provide valuable information to water managers and planners throughout New England. This study investigates correlations between seasonal streamflow indices and three atmospheric circulation patterns: 1) El Nino/Southern Oscillation (ENSO), 2) the North Atlantic Oscillation (NAO), and 3) the Pacific North American (PNA). The streamflow indices considered are the annual seven day low flow (SDLF) and its date of occurrence (SDLFDate), the annual peak flow (PF) and its date of occurrence (PFDate), the annual center of volume (CV) and its date of occurrence (CVDate), the winter/spring center of volume (CVWS) and its date of occurrence (CVWSDate), winter-average (Dec. – March) streamflow, autumn-average(Oct. – Nov.) streamflow, spring-average streamflow (March – June), and summer-average streamflow (July – Sept.). Table 1 summarizes these indices and establishes the notation to be used throughout the rest of this study.