Some PSD datasets and products are not up-to-date due to a system problem. We are working on a fix.
 

Reanalysis model parameters

The SSI analysis and the Global Spectral Model are two of the three principle components (the third being the observation quality control programs) of the NMC data assimiliation system. The system cycles on itself. The Global model moves the system along in time, the SSI corrects the time integration toward the observed values, providing the inital conditions for the next 6 hour integration. The information provided on the NMC WWW pages applies except for horizontal resolution - the Reanalysis runs with Triangular 62 truncation, the current operational model with T126 - and the operational source of observations versus that available to Reanalysis. The fields passed along to PSD come either directly or post-processed from either of models.