Drought monitoring and seasonal hydrological prediction with the NCEP CFS using the Noah-MP land model

Under the support from the current CPO/MAPP program on the transition of latest development on Noah LSM into operation, the Noah LSM with Multiple-Parameterization (Noah MP) options has been implemented in the CFS. The CFS/Noah MP provides a prototype for the next generation of physics-based ensemble approach for seasonal prediction.The improvement in prediction skill is to be accomplished by means of improved representation of land surface processes and land-atmosphere interactions in the NCEP operational global and regional climate prediction systems.The Noah-MP provides choices of parameterizations for 12 different physical processes, especially ground water and dynamics vegetation.

To examine the impact from using the new Noah-MP LSM on CFS prediction sills, T126 CFS reforecast experiments are carried out for selected eleven years (1982, 1987, 1996, 1988, 1986, 1991,1999,2000, 2007, 2011,2012) with four ensemble members whose initial conditions are 00z of May 1- 4 in each year). The eleven years are classified as 5ENSO-cold, 3 warm and 3 neutral years using the May-June-July Nino 3.4 SST as a standard. CFS predictionskill and climatology are compared on an ensemble-basis.CFS performance is also evaluated on the2011 Texas drought prediction.

Results show that the inclusion of the Noah-MP LSM with options for ground water has a positive impact on precipitation prediction skill, deep soil moisture and associated evaporation climatology. The CFS/Noah MP also performs better in depicting precipitation and 2-m temperature patterns during the 2011 summer months, indicating that the ground water and related memory is important to seasonal predictions.