5EASM2: LINKING NEAR-TERM FUTURE CHANGES IN WEATHER AND HYDROCLIMATE IN WESTERN NORTH AMERICA TO ADAPTATION FOR ECOSYSTEM AND WATER MANAGEMENT
Lamont-Doherty Earth Observatory of Columbia University 61 Route 9W Palisades, NY 10964

14. Covariability of climate and Upper Rio Grande Streamflow - PDF

Upper Rio Grande streamflow variability is explained on timescales of months to decades by the combined influence of the El Niño-Southern Oscillation (ENSO), Pacific Decadal Oscillation (PDO), Atlantic Multidecadal Oscillation (AMO) and the North American Monsoon (NAM). The peak in spring-summer streamflow has a positive relationship with Pacific sea surface temperature (SST), and a negative relationship with north Atlantic SST. On monthly timescales, the relationship between streamflow and Pacific SST is nonlinear: warm Pacific episodes produce above normal streamflow, but cold Pacfic episodes have a more varied response in streamflow. On annual timescales, El Niño episodes generally increase the magnitude of upper Rio Grande streamflow.

riogrande
Photo By: Adriel Heisey - High oblique aerial view of the Rio Grande with Ute Mountain. This view is to the southeast on an August morning, with the Sangre de Cristo Mountains on the horizon.

 

The upper Rio Grande is also characterized by decadal variability: periods of high flow and precipitation (1900-1920 and 1979-1994) are found to coincide with the positive PDO and negative AMO phases. Cyclonic flow off the United States west coast, and anomalous moisture convergence located over the upper Rio Grande region, is also prevalent during winters in these high flow decades. The strength of these teleconnections increases toward the south of the basin, where Pacific SST forcing is more important. SST teleconnections and its influence on basin precipitation is found to be more important in the winter preceding spring-summer streamflow. These configurations of ocean and atmosphere explain the observed variability of upper Rio Grande streamflow and provide predictability, which is essential for its effective management and the millions of people relying on its waters.

ute Ute Mountain and upper Rio Grande - Wikimedia Commons

 

 

 

 

 

 

 

 

 

 

 

 

 

 

REFERENCE

  • Pascolini-Campbell, M.A., R. Seager, A. Pinson and B.I. Cook, 2017: Covariability of Climate and Upper Rio Grande Streamflow. J. Hydrology: Regional Studies 13, 58-71, doi.org/10.1016/j.ejrh.2017.07.007. PDF