Vertical structure of humidity and temperature budget residuals over the Mississippi River basin

Analyses have systematic tendencies or budget residuals that are not small. Unlike the budgets in general circulation model simulations, these budget residuals are an important component of analyses’ water and energy budgets. We can either get good budgets or good climates, but not both. To better understand the character of the residuals in the National Centers for Environmental Prediction's (NCEP) global analysis and reanalysis water and energy budgets, the vertical structure of the budget residuals in NCEP's global analyses pertinent to the Mississippi River basin water and energy budgets are described herein. The vertical structure of the residuals is obtained by using NCEP's reanalysis modeling system, which is initialized (started) from NCEP's operational Global Data Assimilation System analyses as well as from the new NCEP reanalyses; forecasts of 1 day duration, 4 times a day, are then made for several years. The budget residuals in the forecasts after the first 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 of moisture and temperature. These residuals may thus be providing clues as to what needs to be improved in analysis systems.