Climatology and interannual variability of diurnal water vapor heating

[1] Tropospheric heating by water vapor absorption of near-infrared (IR) radiation is a leading drive of the propagating diurnal tide. A climatology of monthly diurnal water vapor IR heating rates is derived using National Centers for Environmental Prediction/ National Center for Atmospheric Research (NCEP/NCAR) reanalysis and a global precipitable water (PW) data set. The new climatology updates an existing one compiled in 1982 that provides seasonally averaged IR heating between 35 degreesS and 35 degreesN. The new heating rates have greater temporal and spatial resolution and enable examination of intraseasonal and year-to-year variability over the 10-year span of the PW data set. Our findings suggest that tropical tropospheric variability may be communicated to the diurnal tide (and possibly the middle and upper atmosphere) by means of water vapor heating.