未来甲烷排放增加对平流层水汽和全球臭氧的影响  

The possible effects of future increase in methane emission on the stratospheric water vapor and global ozone.

作　　者：谢飞[1] 田文寿[2] 李建平[1] 张健恺[2] 商林[2] 

机构地区：[1]中国科学院大气物理研究所大气科学和流体力学数值模拟国家重点实验室,北京100029 [2]半干旱气候变化教育部重点实验室(兰州大学),兰州730000

出　　处：《气象学报》2013年第3期555-567,共13页Acta Meteorologica Sinica

基　　金：国家杰出青年项目(41225018);国家973项目(2010CB950400);国家自然科学基金面上项目(41175042);博士后基金(2012M510525)

摘　　要：利用一个耦合的大气化学-气候模式(WACCM3)研究了地表甲烷排放增加对平流层水汽和全球臭氧变化的影响。结果表明,如果地表甲烷的排放量在2000年的基础上增加50%(达到政府间气候变化专门委员会A1B排放情景中2050年的值),平流层水汽体积分数将平均增加约0.8×10^(-6)。南半球平流层甲烷转化为水汽的效率比北半球高。在北半球平流层中,1 mol甲烷分子可以转化为约1.63 mol的水汽分子,而在南半球1 mol甲烷分子大概可以转化为约1.82 mol的水汽分子。甲烷排放增加50%将使全球中低纬度地区以及北半球高纬度地区的臭氧柱总量增加1%—3%,使南半球高纬度地区臭氧柱总量增加近8%,而秋季(南半球春季)南极地区臭氧柱总量增加幅度可高达20%,南极臭氧的这种显著增加主要是由于甲烷增加造成的化学反馈所致。在北半球中高纬度地区,甲烷增加引起的臭氧变化主要与甲烷氧化导致的水汽增加有关。研究还表明,未来甲烷排放增加对臭氧的恢复作用其实与溴化物排放的减少一样重要。Using a statcof-thcart,fully coupled chemistry climate model-Whole Atmosphere Community Climate Model 3 （WACCM3）,the impact of increasing surface emissions of methane （CH4）on stratospheric water vapor and global ozone is investigated.Relative to surface emissions of UHUs in 2000 year, a 50% increase in CHI surface emissions （corresponding to the 2050 value according to the IPCC A1B scenario） will cause an average increase of -0.8×10-6 in water vapor in the stratosphere.The radativc heating effect of increasing CHI on the tropopause contributes 12% to the stratospheric water vapor increases, and the chemical process explains the rest water vapor increases.It is found that the transformation of CH4 into water vapor is more efficient in the southern hemisphere stratosphere than in the northern hemisphere stratosphere.1.63 mol H2O molecule; in the southern hemisphere; 1 mol CH4 molecule may transform into 1.82 mol H2O molecule.The 50% in crease in the CH4 emission would lead to an overall increase of total column ozone（TCO） by 1%-3% at the lower-mid latitudes as well as at the northern high latitudes, and a maximum increase of -8% at the southern high latitudes, with a maximum growth rate of up to -20% over Antaretic in autumn.It is found that the significant TCO increase over Antaretic is mainly caused by a feedback of chemical effect.However, at the northern high latitudes the TCO increase is mainly related to the impact of water vapor increases caused by the oxidation of CH4 on ozone.The study also showed that the effect of increasing methane emissions in the future on ozone recovery is as important as the decrease in bromide emissions.

关 键 词：甲烷排放 大气化学-气候模式 平流层水汽 平流层臭氧 南极臭氧洞 

分 类 号：P465[天文地球—大气科学及气象学]