Surface energy budgeting using remote sensing
Surface energy budgeting assumes importance as the surface energy balance is one of the major factors affecting hydrostatic stability and mixing of atmospheric constituents such as pollutants in lower atmosphere. Remote sensing can be used for surface energy budgeting over large spatial extends to understand changes in surface energy balance and related effects in earth atmospheric boundary layer characteristics and associated processes. An accurate picture of the global energy balance is necessary to detect perturbations in the Earth’s climate system. The top-of-atmosphere radiative energy balance has been relatively well determined by satellites, as compared to the surface energy budget where larger uncertainties exist as surface fluxes cannot be directly measured by satellites. The spatio-temporal variations in distribution of surface energy components such as radiative fluxes at the surface, the sensible, latent and ground heat fluxes are retrieved and examined using multi-year data records from geostationary and polar orbiting satellites. The algorithms for estimating surface energy balance components are evolved and validated against ground measurements carried out over different regions
Retrieving vertical profile of temperature and humidity using Radio Occultation (RO) data
Vertical profiles of atmospheric temperature and humidity are important parameters in atmospheric research, especially for weather forecast and climate change studies. Radio Occultation technique is an effective method to retrieve these profiles by receiving radio signals from GPS navigation satellites. The method makes use of the fact that degree of refraction of radio waves while passing through the atmosphere depends on gradients in air density which in turn depends on temperature and humidity.
Climate change impact assessment
Anticipated/Ensuing climate change is expected to alter the water resources availability, demand and use patterns. Many uncertainties remain about the extent of these climatic changes, as well as about their societal implications. Assessment of vulnerability and resulting risk to water resources due to climate-change impacts is necessary to work out appropriate adaptation and mitigation strategies.
