Vol.:(0123456789) Natural Hazards (2020) 102:689–705 https://doi.org/10.1007/s11069-019-03590-8 1 3 ORIGINAL PAPER Association of modeled PM 2.5 with aerosol optical depth: model versus satellite Nishi Srivastava 1 Received: 21 March 2018 / Accepted: 25 February 2019 / Published online: 4 March 2019 © Springer Nature B.V. 2019 Abstract Particulate matters < 2.5 μm (i.e., PM 2.5 ) are very important for health as well as radiative forcing studies. But over Indian continent, there is scarcity of the observation for PM 2.5 concentration which gets measured over only few locations with very coarse resolution. Limitations on resolution in space and time posed by the real-time measurements caused requirement of other measurements with high resolution in space and time. In this regard, satellite observations and model came up as good alternative as they can produce informa- tion with high resolution. Satellites and chemical transport models play a signifcant role and give wider option to study spatial and temporal patterns of particulate matter, espe- cially for fner mode. In the present work, we have simulated the particulate matters (PM 2.5 ) over the Indian continent from 4–29.5°N and 67–88.5°E with the help of a chemical trans- port model ‘CHIMERE.’ We found its connection with satellite estimate aerosol optical depth (AOD) from MODIS and MISR sensors. Modeled results can be set for higher reso- lution than satellite data, so in the absence of satellite data, these relations can be useful. Particulate matters with aerodynamic radius < 2.5 are a contributor to total aerosol load which causes columnar aerosol optical depth. In this work, we took PM 2.5 concentration as an indicator of aerosol loading and thus compared it with columnar aerosol optical depth. Both approaches are coherent for various seasons on the year except monsoon as in the monsoon season availability of data from satellite was not consistent. Keywords Aerosol · Aerosol optical depth · Particulate matter · Chemical transport model 1 Introduction Atmospheric aerosols are integral part of our environmental and climate system, thus sig- nifcantly afecting the climatic radiative forcing. We understand that anthropogenic aero- sols have strong radiative forcing but our knowledge about the amount and sign of radiative forcing still incorporates large uncertainty. Precise and consistent measurements of aero- sol distribution and properties are required to reduce the gaps in understanding the global radiative efects of aerosol. Aerosol size varies in diferent sizes from fne mode to coarse * Nishi Srivastava nishi.bhu@gmail.com 1 Department of Physics, B.I.T.-Mesra, Ranchi, Jharkhand, India