JAI DEVI JEYARAMAN
@iitram.ac.in
INSTITUTE OF INFRASTRUCTURE TECHNOLOGY RESEARCH AND MANAGEMENT
RESEARCH, TEACHING, or OTHER INTERESTS
Environmental Science, Renewable Energy, Sustainability and the Environment, Environmental Engineering, Pollution
Scopus Publications
Scholar Citations
Scholar h-index
Scholar i10-index
Scopus Publications
Hardik H. Gajjar and Jai Devi Jeyaraman
Informa UK Limited
Hardik H. Gajjar, Jai Devi Jeyaraman, and Daya Shankar Kaul
Springer Science and Business Media LLC
Umangi H. Mehta, Daya S. Kaul, Dane Westerdahl, Zhi Ning, Kai Zhang, Li Sun, Peng Wei, Hardik H. Gajjar, Jai D. Jeyaraman, Mansi V. Patel,et al.
Springer Science and Business Media LLC
A. Nema, D.S. Kaul, K. Mukherjee, and J.D. Jeyaraman
Elsevier BV
J. Jai Devi, Michael H. Bergin, Michael Mckenzie, James J. Schauer, and Rodney J. Weber
Elsevier BV
J. Liu, E. Scheuer, J. Dibb, G. S. Diskin, L. D. Ziemba, K. L. Thornhill, B. E. Anderson, A. Wisthaler, T. Mikoviny, J. J. Devi,et al.
Copernicus GmbH
Abstract. Chemical components of organic aerosol (OA) selectively absorb light at short wavelengths. In this study, the prevalence, sources, and optical importance of this so-called brown carbon (BrC) aerosol component are investigated throughout the North American continental tropospheric column during a summer of extensive biomass burning. Spectrophotometric absorption measurements on extracts of bulk aerosol samples collected from an aircraft over the central USA were analyzed to directly quantify BrC abundance. BrC was found to be prevalent throughout the 1 to 12 km altitude measurement range, with dramatic enhancements in biomass-burning plumes. BrC to black carbon (BC) ratios, under background tropospheric conditions, increased with altitude, consistent with a corresponding increase in the absorption Ångström exponent (AAE) determined from a three-wavelength particle soot absorption photometer (PSAP). The sum of inferred BC absorption and measured BrC absorption at 365 nm was within 3 % of the measured PSAP absorption for background conditions and 22 % for biomass burning. A radiative transfer model showed that BrC absorption reduced top-of-atmosphere (TOA) aerosol forcing by ~ 20 % in the background troposphere. Extensive radiative model simulations applying this study background tropospheric conditions provided a look-up chart for determining radiative forcing efficiencies of BrC as a function of a surface-measured BrC : BC ratio and single scattering albedo (SSA). The chart is a first attempt to provide a tool for better assessment of brown carbon's forcing effect when one is limited to only surface data. These results indicate that BrC is an important contributor to direct aerosol radiative forcing.
Jiumeng Liu, Eric Scheuer, Jack Dibb, Luke D. Ziemba, Kenneth. L. Thornhill, Bruce E. Anderson, Armin Wisthaler, Tomas Mikoviny, J Jai Devi, Michael Bergin,et al.
American Geophysical Union (AGU)
J. Jai Devi, Tarun Gupta, Rajmal Jat, and S. N. Tripathi
Springer Science and Business Media LLC
J. Jai Devi, Tarun Gupta, S. N. Tripathi, and Kamal K. Ujinwal
Informa UK Limited
Human exposure to particulate matter can have significant harmful effects on the respiratory and cardiovascular system. These effects vary with number, size, and chemical composition of particulate matter, which vary significantly with space and time. The Indian Institute of Technology–Kanpur (IITK), Kanpur, India, is a relatively clean academic campus in the northwest of a heavily polluted city, Kanpur. The major objectives of the study were to evaluate total exposure of fine and coarse fractions of PM10 to a typical IITK student resident in different indoor microenvironments within the campus; to evaluate personal exposure to student residents during outdoor trips; and to evaluate personal exposure to a typical student resident carrying out routine activities. In order to account for all the sources of particulate matter exposure, measurements on several different days during the pre-monsoon season were carried out in the most common indoor microenvironments in the campus and during outdoor trips outside the campus. A 15-channel optical particle counter (model 1.108, GRIMM) was used to measure continuous real-time particle size distribution from 0.3 to 20 μm diameter. Using this instrument, exposure for 1 h at different indoor microenvironments was determined. Both the effects of location and activity, which, in turn, account for specific indoor sources and number of occupants, respectively, were carefully evaluated. Re-suspension of particles due to movement of people was found to be a major source of coarse particulate matter exposure. On the other hand, combustion sources led to elevated fine particulate levels. Chalk dust was found to be the major source of fine particulate matter in classrooms. Similar results on other sources of particulate matter are discussed in the paper. To assess the personal average size resolved particulate exposure on a student making a day trip outside the campus, study trips to most common public places in the city in a commonly preferred vehicle were made. Striking correlations between sources/activities and increase in fine and/or coarse particle concentration were clearly visible. To investigate the daily personal exposure and its relation to the activities of a typical student residing in the campus, a 24-h exposure study was done on a student who maintained a time-activity diary. The results provide insight into possible sources and their interaction with human activities in modifying the human exposure levels. A comparison between different microenvironments has been attempted for the first time in an Indian scenario using a real-time aerosol measuring instrument.