The relationship between tibetan snow depth, ENSO, river discharge and the monsoons of Bangladesh

Jeffrey Shaman, Mark Cane, Alexey Kaplan
2005 International Journal of Remote Sensing  
Using satellite estimates of snow depth, we examine the interannual variability of the monsoon rains of Bangladesh, an area greatly affected by land surface hydrological processes including Himalayan snowpack size, snowmelt river flooding, and Bay of Bengal storm surge. For the twentieth century, we found Bangladesh monsoon rainfall (BMR) to be uncorrelated with the All-Indian Monsoon Index. This result is consistent with previous findings for shorter time records. We next used a short 9-year
more » ... cord of satellite estimates of April snow depth for the Himalayan region and concurrent seasonal El Niñ o-Southern Oscillation (ENSO) conditions in the equatorial Pacific to develop an empirical model that explains a high percentage of BMR interannual variability. Inclusion of late spring river discharge levels further improves the empirical model representation of BMR for June-September. These results, though with a limited length satellite record, suggest that BMR interannual variability is constrained by concurrent ENSO conditions, spring Himalayan snowpack size and land surface flooding. The same results could not be obtained from analyses using satellite estimates of snow cover. These findings stress the need for development of a quality longer record of satellite estimated snow depth. The twentieth-century analysis also indicates that BMR should be considered independently of Indian monsoon rainfall.
doi:10.1080/01431160500185599 fatcat:47qwb7ilvrawbbj4wxnqsmxvwe