Effects of climate-induced changes in isoprene emissions after the eruption of Mount Pinatubo
Effects of climate-induced changes in isoprene emissions after the eruption of Mount Pinatubo
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DOI：
10.5194/acp-10-7117-2010
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发表时间：
2010-08
影响因子：
6.3
通讯作者：
P. Telford;J. Lathiére;N. Abraham;A. Archibald;P. Braesicke;Colin Johnson;O. Morgenstern;F. O’Connor;R. Pike;O. Wild;P. Young;D. Beerling;C. Hewitt;J. Pyle
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文献类型：
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作者：
P. Telford;J. Lathiére;N. Abraham;A. Archibald;P. Braesicke;Colin Johnson;O. Morgenstern;F. O’Connor;R. Pike;O. Wild;P. Young;D. Beerling;C. Hewitt;J. Pyle
抽象的。在1990年代，观察到温室气体浓度的增加速度，尤其是甲烷的增加速度发生了变化，原因尚不完全确定。这一时期包括了山体的喷发。皮纳图博和厄尔尼诺暖事件，这两个事件都通过温度、降水和辐射的变化影响了生物地球化学过程。我们研究了这些气候变化对全球异戊二烯排放的影响，以及这些与气候有关的排放对羟基自由基OH的影响，OH是甲烷的主要汇。我们模拟了20世纪90年代初异戊二烯排放量的减少，1992年末和1993年初的最大降幅为40Tg(C)/年，变化幅度为9%。这种减少是由于火山喷发后更凉爽、更干燥的条件造成的。皮纳图博。异戊二烯的排放通过温度和土壤湿度依赖的抑制因子的变化直接减少，也通过总生物量的减少间接减少。异戊二烯排放的减少导致对流层OH的增加，从而导致甲烷汇增加高达5Tg(CH4)/年，与所研究的时间段内估计的源变化相当。异戊二烯的排放和氧化仍然存在许多不确定性，这可能会影响这种影响的确切大小，但其规模足够大，因此它仍然是重要的。
Abstract. In the 1990s the rates of increase of greenhouse gas concentrations, most notably of methane, were observed to change, for reasons that have yet to be fully determined. This period included the eruption of Mt. Pinatubo and an El Nino warm event, both of which affect biogeochemical processes, by changes in temperature, precipitation and radiation. We examine the impact of these changes in climate on global isoprene emissions and the effect these climate dependent emissions have on the hydroxy radical, OH, the dominant sink for methane. We model a reduction of isoprene emissions in the early 1990s, with a maximum decrease of 40 Tg(C)/yr in late 1992 and early 1993, a change of 9%. This reduction is caused by the cooler, drier conditions following the eruption of Mt. Pinatubo. Isoprene emissions are reduced both directly, by changes in temperature and a soil moisture dependent suppression factor, and indirectly, through reductions in the total biomass. The reduction in isoprene emissions causes increases of tropospheric OH which lead to an increased sink for methane of up to 5 Tg(CH4)/year, comparable to estimated source changes over the time period studied. There remain many uncertainties in the emission and oxidation of isoprene which may affect the exact size of this effect, but its magnitude is large enough that it should remain important.