Anish Kumar M. Nair

Multiyear CloudSat and CALIPSO Observations of the Dependence of Cloud Vertical Distribution on Sea Surface Temperature and Tropospheric Dynamics

AbstractUtilizing the synergy of the capabilities of CloudSat and Cloud–Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) and ~4.5 years of their observations, this paper investigates the dependence of the altitude distribution and thickness of tropical clouds on sea surface temperature (SST). Variations in the altitude distribution of clouds with SST show three distinct regimes: SST 29°C. At an SST 24°C. Vertical development of clouds through the 3–12-km-altitude region increases for SST > 27.5°C to achieve maximum cloud occurrence and thickness in the SST range of 29°–30.5°C. Penetration of the deep convective clouds to altitudes >15 km and their frequency of occurrence increase ...

Development of lidar sensor for cloud-based measurements during convective conditions

Atmospheric convection is a natural phenomena associated with heat transport. Convection is strong during daylight periods and rigorous in summer months. Severe ground heating associated with strong winds experienced during these periods. Tropics are considered as the source regions for strong convection. Formation of thunder storm clouds is common during this period. Location of cloud base and its associated dynamics is important to understand the influence of convection on the atmosphere. Lidars are sensitive to Mie scattering and are the suitable instruments for locating clouds in the atmosphere than instruments utilizing the radio frequency spectrum. Thunder storm clouds are composed of hydrometers and strongly scatter the laser light. Recently, a lidar technique was developed at National Atmospheric Research Laboratory (NARL), a Department of Space (DOS) unit, located at Gadanki near Tirupati. The lidar technique employs slant path operation and provides high resolution measurements on cloud base location in real-time. The laser based remote sensing technique allows measurement of atmosphere for every second at 7.5 m range resolution. The high resolution data permits assessment of updrafts at the cloud base. The lidar also provides real-time convective boundary layer height using aerosols as the tracers of atmospheric dynamics. The developed lidar sensor is planned for up-gradation with scanning facility to understand the cloud dynamics in the spatial direction. In this presentation, we present the lidar sensor technology and utilization of its technology for high resolution cloud base measurements during convective conditions over lidar site, Gadanki.