Estimated impact of black carbon deposition during pre-monsoon season from Nepal Climate Observatory – Pyramid data and snow albedo changes over Himalayan glaciers

Article, Other literature type English OPEN
Yasunari, T. J. ; Bonasoni, P. ; Laj, P. ; Fujita, K. ; Vuillermoz, E. ; Marinoni, A. ; Cristofanelli, P. ; Duchi, R. ; Tartari, G. ; Lau, K.-M. (2010)
  • Publisher: European Geosciences Union
  • Journal: (issn: 1680-7324)
  • Related identifiers: doi: 10.5194/acp-10-6603-2010
  • Subject: [ SDU.STU.GL ] Sciences of the Universe [physics]/Earth Sciences/Glaciology

The possible minimal range of reduction in snow surface albedo due to dry deposition of black carbon (BC) in the pre-monsoon period (March–May) was estimated as a lower bound together with the estimation of its accuracy, based on atmospheric observations at the Nepal Climate Observatory – Pyramid (NCO-P) sited at 5079 m a.s.l. in the Himalayan region. A total BC deposition rate was estimated as 2.89 μg m<sup>−2</sup> day<sup>−1</sup> providing a total deposition of 266 μg m<sup>−2</sup> for March–May at the site, based on a calculation with a minimal deposition velocity of 1.0&times;10<sup>&minus;4</sup> m s<sup>−1</sup> with atmospheric data of equivalent BC concentration. Main BC size at NCO-P site was determined as 103.1–669.8 nm by correlation analyses between equivalent BC concentration and particulate size distributions in the atmosphere. The BC deposition from the size distribution data was also estimated. It was found that 8.7% of the estimated dry deposition corresponds to the estimated BC deposition from equivalent BC concentration data. If all the BC is deposited uniformly on the top 2-cm pure snow, the corresponding BC concentration is 26.0–68.2 μg kg<sup>−1</sup>, assuming snow density variations of 195–512 kg m<sup>−3</sup> of Yala Glacier close to NCO-P site. Such a concentration of BC in snow could result in 2.0–5.2% albedo reductions. By assuming these albedo reductions continue throughout the year, and then applying simple numerical experiments with a glacier mass balance model, we estimated reductions would lead to runoff increases of 70–204 mm of water. This runoff is the equivalent of 11.6–33.9% of the annual discharge of a typical Tibetan glacier. Our estimates of BC concentration in snow surface for pre-monsoon season is comparable to those at similar altitudes in the Himalayan region, where glaciers and perpetual snow regions begin, in the vicinity of NCO-P. Our estimates from only BC are likely to represent a lower bound for snow albedo reductions, because we used a fixed slower deposition velocity. In addition, we excluded the effects of atmospheric wind and turbulence, snow aging, dust deposition, and snow albedo feedbacks. This preliminary study represents the first investigation of BC deposition and related albedo on snow, using atmospheric aerosol data observed at the southern slope in the Himalayas.
  • References (45)
    45 references, page 1 of 5

    Aoki, Te., Aoki, Ta., Fukabori, M., Hachikubo, A., Tachibana, Y., and Nishio, F.: Effects of snow physical parameters on spectral albedo and bidirectional reflectance of snow surface, J. Geophys. Res., 105(D8), 10219-10236, 2000.

    Aoki, Te., Motoyoshi, H., Kodama, Y., Yasunari, T. J., Sugiura, K., and Kobayashi, H.: Atmospheric aerosol deposition on snow surfaces and its effect on albedo, SOLA, 2, 13- 16, doi:10.2151/sola.2006-004, available online at: http://www. 13/ article, 2006.

    Aoki, Te., Motoyoshi, H., Kodama, Y., Yasunari, T. J., and Sugiura, K.: Variations of the snow physical parameters and their effects on albedo in Sapporo, Japan, Ann. Glaciol., 46, 375-381, 2007.

    Bollasina, M., Bertolani, L., and Tartari, G.: Meteorological observations at high altitude in the Khumbu Valley, Nepal Himalayas, 1994-1999, Bull. Glaciol. Res., 19, 1-11, available online at:∼bgr/19/BGR19P1.PDF, 2002.

    Bonasoni, P., Laj, P., Angelini, F., Arduini, J., Bonafe`, U., Calzolari, F., Cristofanelli, P., Decesari, S., Facchini, M. C., Fuzzi, S., Gobbi, G. P., Maione, M., Marinoni, A., Petzold, A., Roccato, F., Roger, J. C., Sellegri, K., Sprenger, M., Venzac, H., Verza, G. P., Villani, P., and Vuillermoz, E.: The ABC-Pyramid Atmospheric Research Observatory in Himalaya for aerosol, ozone and halocarbon measurements, Sci. Total Environ., 391(2-3), 252-261, 2008.

    Bonasoni, P., Laj, P., Marinoni, A., Sprenger, M., Angelini, F., Arduini, J., Bonafe`, U., Calzolari, F., Colombo, T., Decesari, S., Di Biagio, C., di Sarra, A. G., Evangelisti, F., Duchi, R., Facchini, M. C., Fuzzi, S., Gobbi, G. P., Maione, M., Panday, A., Roccato, F., Sellegri, K., Venzac, H., Verza, G. P., Villani, P., Vuillermoz, E., and Cristofanelli, P.: Atmospheric Brown Clouds in the Himalayas: first two years of continuous observations at the Nepal-Climate Observatory at Pyramid (5079 m), Atmos. Chem. Phys. Discuss., 10, 4823-4885, doi:10.5194/acpd10-4823-2010, 2010.

    Cong, Z., Kang, S., and Qin, D.: Seasonal features of aerosol particles recorded in snow from Mt. Qomolangma (Everest) and their environmental implications, J. Environ. Sci., 21(7), 914- 919, 2009.

    Cong, Z., Kang, S., Dong, S., Liu, X., and Qin, D.: Elemental and individual particle analysis of atmospheric aerosols from high Himalayas, Environ. Monit. Assess., 160, 323-335, doi:10.1007/s10661-008-0698-3, 2010.

    Conway, H., Gades, A., and Raymond C. F.: Albedo of dirty snow during conditions of melt, Water Resour. Res., 32(6), 1713-1718, 1996.

    Decesari, S., Facchini, M. C., Carbone, C., Giulianelli, L., Rinaldi, M., Finessi, E., Fuzzi, S., Marinoni, A., Cristofanelli, P., Duchi, R., Bonasoni, P., Vuillermoz, E., Cozic, J., Jaffrezo, J. L., and Laj, P.: Chemical composition of PM10 and PM1 at the highaltitude Himalayan station Nepal Climate Observatory-Pyramid (NCO-P) (5079 m a.s.l.), Atmos. Chem. Phys., 10, 4583-4596, doi:10.5194/acp-10-4583-2010, 2010.

  • Metrics
    No metrics available
Share - Bookmark