RSG Contacts
Overview
We retrieve ozone profiles from satellite measurements in the UV-vis spectral region. Our algorithm has been developed to have optimal sensitivity to tropospheric ozone. Our data is publically available from a number of sources (e.g. through the ESA Ozone ECV project) and directly from the Remote-Sensing Group.
Ozone (O3) is formed from 3 oxygen molecules as a result of interaction with light.
Ozone is an important atmospheric trace gas, absorbing ultraviolet (UV) radiation from the sun that would otherwise damage the cells of living organisms at the Earth's surface. In the stratosphere, where approximately 90 % of ozone is found, the vertical distribution determines heating rates and thereby also dynamics. The vertical distribution of stratospheric ozone is determined by the Chapman cycle (Chapman, 1930), and catalytic cycles involving nitrogen, hydrogen and halogen radicals. In the troposphere, ozone is produced though complex reaction pathways involving nitrogen oxides (NOx) and volatile organic compounds (VOCs).
Ozone is also introduced by exchange from the stratosphere, particularly at mid-latitudes. As a secondary pollutant from anthropogenic and biomass burning sources, it is an environmental hazard particularly in urban environments because it is a lung irritant. High levels of ozone have been linked to increased mortality/excess deaths when associated with localised heat wave events (Gryparis et al., 2004). Tropospheric ozone can be damaging to agriculture by increasing the failure rate of crops (Holloway et al., 2012). For these reasons, it is vitally important to monitor ozone in the troposphere as well as the stratosphere, but in situ surface observations and ozonesondes are sparse and heavily favour the Northern Hemisphere.
Tropospheric ozone is also a greenhouse gas. The uncertainty in estimates of radiative forcing from tropospheric ozone is as large as that associated with the non-well mixed greenhouse gases (IPCC, 2013) and as such good knowledge of the atmospheric concentration of tropospheric ozone is required. This uncertainty remains in part due to the reliance on atmospheric models and their spread, in addition to uncertainty about pre-industrial ozone amount. Estimates do not currently incorporate any information from satellites (IPCC, 2013). An accurate, contemporary distribution of tropospheric ozone from satellites would help to verify chemistry transport models (CTMs) and coupled chemistry-climate models (CCMs), and hence their estimates of radiative forcing and the forward projections by CCMs. The MetOp series and its successor MetOp-SG/Sentinel 5 have the potential to monitor tropospheric as well as stratospheric ozone in the decades to come.
References:
Gryparis, A., Forsberg, B., Katsouyanni, K., Analitis, A., Touloumi, G., Schwartz, J., Samoli, E., Medina, S., Anderson, H. R., Niciu, E. M., Wichmann, H. E., Kriz, B., Kosnik, M., Skorkovsky, J., Vonk, J. M., and Dortbudak, Z.: Acute effects of ozone on mortality from the “Air pollution and health: A European approach" project, Am. J. Resp. Crit. Care, 170, 1080–1087, doi:10.1164/rccm.200403-333OC, 2004
Hollaway, M.J., S. R. Arnold, A. J. Challinor, and L. D. Emberson.: Intercontinental trans-boundary contributions to ozone-induced crop yield losses in the Northern Hemisphere. Biogeosciences, 9, 271–292, 2012, doi:10.5194/bg-9-271-2012. http://biogeosciences.net/9/271/2012/bg-9-271-2012.pdf
IPCC: Climate Change 2013: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change, edited by: Stocker, T. F., Qin, D., Plattner, G.-K., Tignor, M., Allen, S. K., Boschung, J., Nauels, A., Xia, Y., Bex, V., and Midgley, P. M., Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, 1535 pp., doi:10.1017/CBO9781107415324, 2013.
Miles, G. M., Siddans, R., Kerridge, B. J., Latter, B. G., and Richards, N. A. D.: Tropospheric ozone and ozone profiles retrieved from GOME-2 and their validation, Atmos. Meas. Tech. Discuss., 7, 7923-7962, doi:10.5194/amtd-7-7923-2014, 2014. http://www.atmos-meas-tech.net/8/385/2015/amt-8-385-2015.pdf
Munro, R., Siddans, R., Reburn, W. J., and Kerridge, B. J.: Direct measurement of tropospheric ozone distributions from space, Nature, 392, 168–171, doi:10.1038/32392, 1998. http://www.nature.com/nature/journal/v392/n6672/abs/392168a0.html
For more information please contact: RAL Space Enquiries
