Trends in Radiative Fluxes Over the Indian Region
B. Padmakumari, Vijay Kumar Soni and M.N. Rajeevan
The various fluxes of radiation to and from the Earth’s surface are the important components of the Earth Radiation Budget. The incoming solar radiation is the primary source of energy for the Earth’s environment that drives weather and climate. The evolution of Earth’s climate is largely regulated by the global energy balance. The spatial and temporal variation in the global energy balance or Earth radiation budget affects various climatic parameters such as atmospheric and oceanic circulations, glaciers, the components of the hydrological cycle, plant productivity, and terrestrial carbon uptake (Ramanathan et al. 2001; Ohmura et al. 2007; Wild et al. 2008). Though Earth’s radiation budget plays a major role in the climate system, there exists significant uncertainties in the quantification of its various components and depiction in climate models (Wild et al. 2012 and the references there in). Radiation budget of the Earth’s system is perturbed through the modifications of the atmospheric composition of greenhouse gases and aerosols through natural as well as human activities and clouds.
Aerosols and clouds are two major controlling factors that affect the surface reaching solar radiation or radiative flux (Rs, also known as global irradiance), which in turn affect other radiative fluxes. Aerosols through their direct (by
B. Padmakumari (H)
Indian Institute of Tropical Meteorology, Earth System Science Organization,
India Meteorological Department, Earth System Science Organization,
New Delhi 11003, India
Earth System Science Organization, Ministry of Earth Sciences,
New Delhi 11003, India
© Springer Science+Business Media Singapore 2017 145
M.N. Rajeevan and S. Nayak (eds.), Observed Climate Variability and Change Over the Indian Region, Springer Geology, DOI 10.1007/978-981-10-2531-0_9
scattering and absorption) and indirect (through changes in cloud microphysics) forcings have profound influence on solar radiation reaching the surface. Unlike the uniform distribution of greenhouse gases due to long lifetimes, aerosols show large spatial and temporal variability due to their short lifetimes of a week or less. As compared to global warming, global or solar dimming has received prominent attention only in the recent decades because of its profound climatic and environmental implications. The changes in the net solar radiation at the surface affect the surface energy budget and may affect the strength of the hydrological cycle and many other climatic parameters.