Atmospheric circulation features associated to Argentinean Andean rivers discharge variability

• Main Authors: Araneo, D.C., Compagnucci, R.H.
• Format: Journal/Newspaper
• Language: unknown
• Subjects: Atmospheric pressure; Discharge (fluid mechanics); Precipitation (meteorology); Rivers; Runoff; Storms; Atmospheric circulation; Wave pattern; Atmospheric movements; low pressure system; river discharge; storm track; Argentina; Atuel River; Chubut; Chubut River; Drake Passage; South America
• Online Access: https://hdl.handle.net/20.500.12110/paper_00948276_v35_n1_p_Araneo

Winter atmospheric circulation patterns and their relationship to runoff variability in the Atuel and Chubut rivers of Argentina are analyzed. The most important atmospheric low levels condition associated with high (low) Atuel discharges is the weakening (strengthening) of the mean atmospheric flow, while the same feature is displaced 5° southward for Chubut. At high levels, results suggest the existence of a NW-SE direction wave pattern extending from Australia to the South Atlantic, favoring positive (negative) pressure anomalies West of the Drake Passage, which deflect the storm tracks northward (southward) and hence increase (decrease) precipitations and subsequent Atuel discharges. In contrast, Chubut discharges are mainly controlled by a shorter wave pattern along the subtropical Pacific, which zonally crosses South America. This pattern helps to maintain low (high) pressure anomalies off the Chilean coast at the upper-river basin latitude for high (low) Chubut runoffs. Copyright 2008 by the American Geophysical Union.