Dust events and their influence on aerosol optical properties over Jaipur in Northwestern India
- 353 Downloads
In this study, we systematically document the link between dust episodes and local scale regional aerosol optical properties over Jaipur located in the vicinity of Thar Desert in the northwestern state of Rajasthan. The seasonal variation of AOT500 nm (aerosol optical thickness) shows high values (0.51 ± 0.18) during pre-monsoon (dust dominant) season while low values (0.36 ± 0.14) are exhibited during winter. The Ångström wavelength exponent has been found to exhibit low value (<0.25) indicating relative dominance of coarse-mode particles during pre-monsoon season. The AOT increased from 0.36 (Aprilmean) to 0.575 (May–Junemean). Consequently, volume concentration range increases from April through May–June followed by a sharp decline in July during the first active phase of the monsoon. Significantly high dust storms were observed over Jaipur as indicated by high values of single scattering albedo (SSA440 nm = 0.89, SSA675 nm = 0.95, SSA870 nm = 0.97, SSA1,020 nm = 0.976) than the previously reported values over IGP region sites. The larger SSA values (more scattering aerosol), especially at longer wavelengths, is due to the abundant dust loading, and is attributed to the measurement site’s proximity to the Thar Desert. The mean and standard deviation in SSA and asymmetry parameter during pre-monsoon season over Jaipur is 0.938 ± 0.023 and 0.712 ± 0.017 at 675 nm wavelength, respectively. Back-trajectory air mass simulations suggest Thar Desert in northwestern India as the primary source of high aerosols dust loading over Jaipur region as well as contribution by long-range transport from the Arabian Peninsula and Middle East gulf regions, during pre-monsoon season.
KeywordsDust Aerosols Optical properties Transport Climate
Aerosols optical thickness
Ångström wavelength exponent
Indo Gangetic plains
Single scattering albedo
We gratefully acknowledge and thank the AERONET group for making all the data available in the form of Level 2.0 quality assured product after necessary screening and post calibrations. The authors thank the NOAA Air Resources Laboratory (ARL) for the provision of the HYSPLIT transport and dispersion model and website http://www.arl.noaa.gov/ready.php used in this publication. This research was also supported by Department of Science and Technology (DST), Govt. of India as a research grant under project SR/S4/AS:39/2009. We also acknowledge wunderground.com and the India Meteorological Department for providing the data. The first authors also acknowledge the Vice Chancellor, BIT Prof Ajay Chakrabarty and Executive Director Prof Purnendu Ghosh for providing the resources that enabled us to carry out this study.
- Beegum, S. N., Moorthy, K. K., Nair, V. S., Babu, S. S., Satheesh, S. K., Vinoj, V., et al. (2008). Characteristics of spectral aerosol optical depths over India during ICARB. Journal of Earth System Science, 117, 303–313.Google Scholar
- Bonasoni, P., Laj, P., Marinoni, A., Sprenger, M., Angelini, F., Arduini, J., et al. (2010). Atmospheric brown clouds in the Himalayas: first two years of continuous observations at the Nepal Climate Observatory-Pyramid (5079 m). Atmospheric Chemistry and Physics, 10, 7515–7531. doi: 10.5194/acp-10-7515-2010.
- Decesari, S., Facchini, M. C., Carbone, C., Giulianelli, L., Rinaldi, M., Finessi, E., et al. (2010). Chemical composition of PM10 and PM1 at the high-altitude Himalayan station Nepal Climate Observatory-Pyramid (NCO-P) (5079 ma.s.l.). Atmospheric Chemistry and Physics, 10, 4583–4596.CrossRefGoogle Scholar
- Dubovik, O., Sinyuk, A., Lapyonok, T., Holben, B. N., Mishchenko, M., Yang, P., et al. (2006). Application of spheroid models to account for aerosol particle non-sphericity in remote sensing of desert dust. Journal of Geophysical Research, 111, D11208. doi: 10.1029/2005JD006619.CrossRefGoogle Scholar
- Ganguly, D., Ginoux, P., Ramaswamy, V., Winker, D. M., Holben, B. N., & Tripathi, S. N. (2009). Retrieving the composition and concentration of aerosols over the Indo-Gangetic basin using CALIPSO and AERONET data. Geophysical Research Letters, 36, L13806. doi: 10.1029/2009GL038315.CrossRefGoogle Scholar
- Gautam, R., Hsu, N. C., Tsay, S. C., Lau, K. M., Holben, B., Bell, S., et al. (2011). Accumulation of aerosols over the Indo-Gangetic plains and southern slopes of the Himalayas: distribution, properties and radiative effects during the 2009 pre-monsoon season. Atmospheric Chemistry and Physics, 11, 12841–12863. doi: 10.5194/acp-11-12841-2011.CrossRefGoogle Scholar
- Gobbi, G. P., Angelini, F., Bonasoni, P., Verza, G. P., Marinoni, A., & Barnaba, F. (2010). Sunphotometry of the 2006–2007 aerosol optical/radiative properties at the Himalayan Nepal Climate Observatory-Pyramid (5079 m a.s.l.). Atmospheric Chemistry and Physics, 10, 11209–11221. doi: 10.5194/acp-10-11209-2010.CrossRefGoogle Scholar
- Kaskaoutis, D. G., Kalapureddy, M. C. R., Krishna Moorthy, K., Devara, P. C. S., Nastos, P. T., Kosmopoulos, P. G., et al. (2010). Heterogeneity in pre-monsoon aerosol types over the Arabian Sea deduced from ship-borne measurements of spectral AOTs. Atmospheric Chemistry and Physics, 10, 4893–4908. doi: 10.5194/acp-10-4893-2010.CrossRefGoogle Scholar
- Nair, V. S., Moorthy, K. K., Alappattu, D. P., Kunhikrishnan, P. K., George, S., Nair, P. R., et al. (2007). Wintertime Aerosol Characteristics over the Indo-Gangetic Plain (IGP): impacts of local boundary layer processes and long range transport. Journal of Geophysical Research, 112, D13205.CrossRefGoogle Scholar
- Pant, P., Hegde, P., Dumka, U. C., Sagar, R., Satheesh, S. K., Moorthy, K. K., et al. (2006). Aerosol characteristics at a high-altitude location in central Himalayas: optical properties and radiative forcing. Journal of Geophysical Research, 111, D17206. doi: 10.1029/2005JD006768.CrossRefGoogle Scholar
- Parameswaran, K., & Vijayakumar, G. (1994). Effect of relative humidity on aerosol size distribution. Indian Journal of Radio and Space Physics, 23(3), 175–188.Google Scholar
- Prospero, J. M., Ginoux, P., Torres, O., Nicholson, S. E., & Gill, T. E. (2002). Environmental characterization of global sources of atmospheric soil dust identified with the Nimbus 7 Total Ozone Mapping Spectrometer (TOMS) absorbing aerosol product. Reviews of Geophysics, 40(1), 1002. doi: 10.1029/2000RG000095.CrossRefGoogle Scholar
- Ramanathan, V., Li, F., Ramana, M. V., Siva, P. S., Kim, D., Corrigan, C. E., et al. (2007). Atmospheric brown clouds: hemispherical and regional variations in long range transport, absorption and radiative forcing. Journal of Geophysical Research, 112. doi: 10.1029/2006JD008124.
- Russell, P. B., Bergstrom, R. W., Shinozuka, Y., Clarke, A. D., DeCarlo, P. F., Jimenez, J. L., et al. (2010). Absorption Ångström exponent in AERONET and related data as an indicator of aerosol composition. Atmospheric Chemistry and Physics, 10, 1155–1169. doi: 10.5194/acp-10-1155-2010.CrossRefGoogle Scholar
- Sikka, D. R. (1997). Desert climate and its dynamics. Current Science, 72(1), 35–46.Google Scholar
- Verma, S., Worden, J., Payra, S., Jourdain, L., & Shim, C. (2008). Characterizing the long-range Transport of Black Carbon Aerosols during Transport and Chemical Evolution over the Pacific (TRACE-P) Experiment. Environmental Monitoring and Assessment, 154(1–4), 85–92. doi: 10.1007/s10661-008-0379-2. Springer.Google Scholar