Increasing influence of air temperature on upper Colorado River streamflow. Issue 5 (9th March 2016)

• Record Type: Journal Article
• Authors: Woodhouse, Connie A.; Pederson, Gregory T.; Morino, Kiyomi; McAfee, Stephanie A.; McCabe, Gregory J.
• Is Part Of: Geophysical research letters. Volume 43:Issue 5(2016)
• Page Start: 2174
• Page End: 2181
• Publication Date: 2016-03-09
• Subjects: Colorado River Basin -- warming temperatures -- water year streamflow -- soil moisture; Geophysics -- Periodicals; Planets -- Periodicals; Lunar geology -- Periodicals; 550
• DOI: 10.1002/2015GL067613
• Languages: English
• ISSNs: 0094-8276

Abstract

Abstract: This empirical study examines the influence of precipitation, temperature, and antecedent soil moisture on upper Colorado River basin (UCRB) water year streamflow over the past century. While cool season precipitation explains most of the variability in annual flows, temperature appears to be highly influential under certain conditions, with the role of antecedent fall soil moisture less clear. In both wet and dry years, when flow is substantially different than expected given precipitation, these factors can modulate the dominant precipitation influence on streamflow. Different combinations of temperature, precipitation, and soil moisture can result in flow deficits of similar magnitude, but recent droughts have been amplified by warmer temperatures that exacerbate the effects of relatively modest precipitation deficits. Since 1988, a marked increase in the frequency of warm years with lower flows than expected, given precipitation, suggests continued warming temperatures will be an increasingly important influence in reducing future UCRB water supplies. Key Points: When UCRB flow departs from precipitation, temperature is a major forcing Since 1988, flows have often been less than expected given winter precipitation Warm temperatures exacerbated modest precipitation deficits in the 2000s drought