Fast nitrogen oxide photochemistry in Summit,Greenland snow |
| |
| Institution: | 1. Climate Change Research Center, Institute for the Study of Earth, Oceans and Space, University of New Hampshire, Durham, NH 03824, USA;2. Department of Civil and Environmental Engineering, Michigan Technological University, Houghton, MI, USA;1. National Institute of Advanced Industrial Science and Technology (AIST), NMIJ, Tsukuba 305-8568, Japan;2. RIKEN SPring-8 Centre, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148, Japan;3. Japan Synchrotron Radiation Research Institute, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198, Japan;1. SHU centre of green urban mining & industry ecology, School of Environmental and Chemical Engineering, Shanghai University, No. 333 Nanchen Rd., Shanghai 200444, PR China;2. Shanghai Institute of Materials Genome, Shanghai, No. 99 Shangda Rd., Shanghai 200444, PR China;1. Department of Earth and Environmental Sciences, University of Rochester, Rochester, NY 14627, USA;2. Department of Physics and Astronomy, University of Rochester, Rochester, NY 14627, USA;1. Environment Research Institute, Shandong University, Ji''nan, Shandong, China;2. Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hong Kong, China;3. Environmental Protection Department, Government of the Hong Kong Special Administrative Region, Hong Kong, China |
| |
| Abstract: | During the 1999 summer field season at Summit, Greenland, we conducted several series of experiments to follow up on our 1998 discovery that NOx is released from the sunlit snowpack. The 1999 experiments included measurements of HONO in addition to NO and NO2, and were designed to confirm, for Greenland snow, that the processes producing reactive nitrogen oxides in the snow are largely photochemical. Long duration experiments (up to 48 h) in a flow-through chamber and in the natural snowpack revealed sun-synchronous diurnal variations of all three reactive nitrogen oxides. In a second set of experiments we alternately shaded or exposed snow (again in the natural snowpack and in the chamber) to ambient sunlight for short periods to reduce any temperature changes during variations in light intensity. All three N oxides increased (decreased) very rapidly when sunlit (shaded). In all experiments NO2 was approximately 3-fold more abundant than NO and HONO (which were at similar levels). Higher concentrations of NO3? in the snow resulted in higher mixing ratios of HONO, NO and NO2 in the snow pore air, consistent with our hypothesis that photolysis of NO3? is the source of the reactive N oxides. |
| |
| Keywords: | |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
