INTERANNUAL VARIABILITY OF PRECIPITABLE WATER

The 12-month running means of the surface-to-500 mb precipitable water obtained from analysis of radiosonde data at seven selected locations showed three types of variability viz: (1) quasi-biennial oscillation s; these were different in nature at different latitudes and also diff erent from the QBO of the stratospheric tropical zonal winds; (2) deca dal effects; these were prominent at middle and high latitudes and (3) linear trends; these were prominent at low latitudes, up trends in th e Northern Hemisphere and downtrends in the Southern Hemisphere.