Hydroclimatology of continental watersheds

Journal Article · Wed Mar 01 04:00:00 EST 1995 · Water Environment Research

DOI:https://doi.org/10.1029/94WR02376· OSTI ID:81166

Cayan, D R ^[1]; Georgakakos, K P ^[2]

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1. Scripps Institution of Oceanography, La Jolla, CA (United States)
2. Univ. of Iowa, Iowa City and Hydrologic Research Center, San Diego, CA (United States)

We diagnose the spatial patterns and further examine temporal behavior of anomalous monthly-seasonal precipitation, temperature, and atmospheric circulation in relationship to hydrologic (soil water and potential evapotranspiration) flutuations at two watersheds in the central United States. The bulk hydrologic abalance at each of the two watersheds, Boone River, Iowa (BN), and Bird Creek, Oklahoma (BC), was determined from the rainfall-runoff-routing watershed model described in part 1. There are many similarities among the hydroclimatic linkages at the two basins. In both, relationships with precipitation and temperature indicate that the forcing occurs on regional scales, much larger than the individual watersheds. Precipitation exhibits anomaly variability over 500-km scales, and sometimes larger. Anomalous temperature, which is strongly correlated with potential evapotranspiration, often extends from the Great Plains to the Appalachian Mountains. Seasonally, the temperature and precipitation anomalies tend to have greatest spatial coherence in fall and least in summer. The temperature and precipitation tend to have out-of-phase anomalies (e.g., warm associated with dry). Thus low soil water conditions are reinforced by low precipitation and high potential evapotranspiration, and vice versa for high soil water. Soil water anomalies in each basin accumulate over a history of significant large-scale climate forcing that usually appears one or two seasons in advance. These forcing fields are produced by atmospheric circulation anomaly patterns that often take on hemispheric scales. BN and BC have strong similarities in their monthly circulation patterns producing heavy/light monthly precipitation episodes, the primary means of forcing of the watersheds. The patterns exhibit regional high or low geopotential anomalies just upstream over the western United States or near the center of the country. 25 refs., 15 figs., 1 tab.

• OSTI ID: 81166
• Journal Information: Water Environment Research, Journal Name: Water Environment Research Journal Issue: 3 Vol. 31; ISSN WAERED; ISSN 1061-4303
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
AIR-BIOSPHERE INTERACTIONS
ATMOSPHERIC PRECIPITATIONS
CLIMATE MODELS
CLIMATES
CORRELATIONS
FEEDBACK
HYDROLOGY
METEOROLOGY
MOISTURE
PARAMETRIC ANALYSIS
SEASONAL VARIATIONS
SOILS
WATERSHEDS