caa a22 4500 477061443 CHVBK 20180405111401.0 cr unu---uuuuu 170330e19961101xx s 000 0 eng 10.1007/BF00053796 doi (NATIONALLICENCE)springer-10.1007/BF00053796 Changing trends in tropospheric methane and carbon monoxide: A sensitivity analysis of the OH-radical [Elektronische Daten] [Han Van Dop, Maarten Krol] A sensitivity analysis is performed in order to study recently observed changes in atmospheric methane and carbon monoxide trends. For the analysis we have adapted a one-dimensional transport/chemistry model in order to comply with changes in vertical transport, stratosphere-troposphere flux of ozone, the water vapour cycle and the short-wave radiative transfer. In addition we have formulated an improved relationship which expresses the steady state OH concentration in terms of longer lived compounds which has a fair agreement with the one-dimensional model results. An analysis of the observed changes and trends in methane and carbon monoxide shows that both emissions and changes in global OH concentrations can be main causes for the observed changes. Average methane emissions have slowed down, particularly in the NH, in the last five years, though perhaps not very significantly. Carbon monoxide emissions are decreasing faster in the last couple of years than in the period 1983-1990. The study suggests that climate fluctuations (tropospheric water vapour, temperature and convective activity) and the stratospheric ozone depletion (tropospheric UV radiation) have a significant influence on tropospheric composition and thus on trends in methane and carbon monoxide concentrations. Kluwer Academic Publishers, 1996 tropospheric chemistry nationallicence hydroxyl radical nationallicence UV-radiation nationallicence Van Dop Han Institute for Marine and Atmospheric Research (IMAU), Utrecht University, PO Box 80005, 3508 TA, Utrecht, The Netherlands aut Krol Maarten Institute for Marine and Atmospheric Research (IMAU), Utrecht University, PO Box 80005, 3508 TA, Utrecht, The Netherlands aut Journal of Atmospheric Chemistry Kluwer Academic Publishers; http://www.wkap.nl 25/3(1996-11-01), 271-288 0167-7764 25:3<271 1996 25 10874 https://doi.org/10.1007/BF00053796 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00053796 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Van Dop Han Institute for Marine and Atmospheric Research (IMAU), Utrecht University, PO Box 80005, 3508 TA, Utrecht, The Netherlands aut NATIONALLICENCE 700 1- Krol Maarten Institute for Marine and Atmospheric Research (IMAU), Utrecht University, PO Box 80005, 3508 TA, Utrecht, The Netherlands aut NATIONALLICENCE 773 0- Journal of Atmospheric Chemistry Kluwer Academic Publishers; http://www.wkap.nl/ 25/3(1996-11-01), 271-288 0167-7764 25:3<271 1996 25 10874 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer