VERTICAL STRUCTURE OF HUMIDITY AND TEMPERATURE BUDGET RESIDUALS OVER THE MISSISSIPPI RIVER BASIN

Analyses have systematic tendencies or budget residuals that are not s mall. Unlike the budgets in general circulation model simulations, the se budget residuals are an important component of analyses' water and energy budgets. We can either get good budgets or good climates, but n ot both. To better understand the character of the residuals in the Na tional Centers for Environmental Prediction's (NCEP) global analysis a nd reanalysis water and energy budgets, the vertical structure of the budget residuals in NCEP's global analyses pertinent to the Mississipp i River basin water and energy budgets are described herein. The verti cal structure of the residuals is obtained by using NCEP's reanalysis modeling system, which is initialized (started) from NCEP's operationa l Global Data Assimilation System analyses as well as from the new NCE P reanalyses;forecasts of 1 day duration, 4 times a day, are then made for several years. The budget residuals in the forecasts after the fi rst 6 hours are similar to the original residuals in the analyses and reanalyses. The residuals appear to be related to a summertime ''spin- down'' and wintertime ''spin-up'' in cumulus convection, an adjustment in boundary layer diffusive transports near the surface and near the top of the boundary layer, and adjustments in large-scale transports o f moisture and temperature. These residuals may thus be providing clue s as to what needs to be improved in analysis systems.