Contact Person: Misra, Vasubandhu

Collaborators: Misra, V.

Institutions: Florida State University

Funding Agency: NOAA

Status: Funded

Filed Under: Climate Sciences, Water

Abstract: In this proposal we are proposing to produce experimental high-resolution retrospective regional climate forecasts for the North American Monsoon (NAM) and the South American Monsoon (SAM) by nesting the regional spectral model (RSM) into the climate forecast system (CFS) of the National Center for Environmental Prediction (NCEP). This project is unique for the following reasons: 1. It is adopting new nesting strategies of anomaly nesting (AN) and scale selective bias correction that have shown to enhance the skill of the seasonal climate integrations from the RSM. The proposed novel downscaling techniques shall be leveraging from the huge suite of existing CFS hindcasts. 2. The nesting of the RSM is being done in a global dynamical-coupled prediction system of the NCEP CFS. 3. It is expanding the scope of the NCEP CFS to hydrologic prediction of streamflow and river discharge of some major river basins in NAM and SAM from the implementation of an off line river routing scheme. 4. A single regional domain that includes both NAM and SAM will be used to enable the study of the dry and wet monsoons. It is proposed to conduct 10 years of Boreal summer (Jun-Jul-Aug) and winter (Jan-Feb-Mar) seasonal integrations with the RSM at 60km horizontal resolution nested into each of the 15 ensemble members of the CFS. The scientific questions to be pursued in this project from these model integrations are as follows:

• How do the proposed global and regional model prediction experiments reproduce the observed summer precipitation and surface temperature over the American Monsoon regions?
• How is the predictability over the American Monsoon regions associated with the leading patterns of climate variability? How much of the predictability of the resulting seasonal precipitation anomalies can be downscaled to local precipitation variability?
• What is the relative influence of the intraseasonal variability and ENSO over the monsoon regions? How does the regional model simulate the interactions between the local processes and regional and larger scale variability?
• Can useful probabilistic predictions be made of seasonal, intraseasonal variability of precipitation, river discharge (over major river basins such as the Amazon, La Plata, Rio Grande, Colorado river basins)?
• What is the role of the bias in SST predictions from CFS on the downscaled seasonal climate predictions of SAM and NAM?
• How is predictability of precipitation, base flow and surface runoff related to streamflow predictability? (Inter-river basin comparisons will also be part of this study).