Space and Atmospheric Sciences Division, PRL

Conventionally, terrestrial atmosphere refers to the region from the Earth's surface to around 100 km, wherein constituent gases are well mixed. While troposphere is often referred to as the lower atmosphere, stratosphere and mesosphere are collectiv osphere, stratosphere and mesosphere are collectively called the middle atmosphere. The region beyond 100 km is called Near-Earth space which eventually merges to interplanetary space. The ionosphere and magnetosphere are part of the Near-Earth space and the interplanetary space starts beyond the magnetosphere of the Earth. The research activities in the Space and Atmospheric Sciences (SPASC) division are aimed at understanding the radiative, chemical, ionization, and dynamical processes in the Earth's atmosphere and near-Earth space environment by employing state-of-the-art and in-house built rocket-, balloon, and ground-based experiments, optical and radio probing techniques, laboratory experiments along with theoretical simulation, numerical modelling, artificial intelligence/machine learning tools. The current research foci of the SPASC division include the studies of Sun-Earth interactions, space weather, coupling, energetics and dynamics of atmospheric regions, investigations of solar disturbances/geomagnetic storms, global-scale atmospheric circulation, characterization of aerosols and their impact on Earth’s radiation budget, chemistry and dynamics of trace gases and volatile organic compounds, cloud and boundary layer dynamics, and global warming/ climate change. Opportunities also exist for use of data from the experiments of ongoing Indian space missions like Aditya-L1, and upcoming dual-aeronomy satellite mission DISHA (Disturbed and quiet time Ionosphere-thermosphere System at High Altitudes), and missions to Venus/Mars. Under the broader area of space physics, the SPASC division is involved in the investigations of solar terrestrial interactions, solar effects on the interplanetary medium, earth’s magnetosphere-ionosphere-thermosphere interactions, space weather and its effects on societal applications, mesosphere-lower thermosphere dynamics, building of ground- and space-based optical and radio instruments. The Division plays an important role in the Indian space science programs, namely, Aditya-L1 mission, the upcoming dual satellite Aeronomy mission, DISHA, as well as missions to Venus/Mars, wherein PRL is the Science lead of ISRO’s DISHA mission. SPASC faculty members are playing lead roles in major international programs such as the PRESTO (Predictability of the Variable Solar-Terrestrial Coupling) of the Scientific Committee on Solar-Terrestrial Physics (SCOSTEP). The research in this area pertains to studies of physicochemical and radiative processes in the lower atmosphere, tropospheric-stratospheric interactions, and middle-atmospheric dynamics. High quality and outstanding research with focus on characterisation of atmospheric aerosols, their spatial and temporal variations, their linkages with physical, chemical and dynamical process and their impact on environment, radiation budget, radiative forcing and climate are conducted through state-of-the-art observations and modelling. Comprehensive measurements and modelling of ozone, volatile organic compounds (VOCs) and other trace gases, cloud characteristics and boundary layer dynamics are being conducted. SPASC faculty lead the ISRO's Atmospheric Trace Gases-Chemistry, Transport, and Modelling (AT-CTM), and serve as Principal Investigator in the National Carbonaceous Aerosols Programme (NCAP) Carbonaceous Aerosol Emissions, Source apportionment and Climate impacts (COALESCE) under the Ministry of Environment, Forests, and Climate Change, and provide the technical support to the National Clean Air Program.