Bromoform as a source of stratospheric bromine
Bromoform as a source of stratospheric bromine
复制标题
DOI：
10.1029/2000gl011444
复制
发表时间：
2000-07
影响因子：
5.2
通讯作者：
W. Sturges;D. Oram;L. Carpenter;S. Penkett;A. Engel
中科院分区：
文献类型：
--
作者：
W. Sturges;D. Oram;L. Carpenter;S. Penkett;A. Engel
我们通过气球、飞机和地面站测量了对流层和平流层下部（海平面至17公里）的溴仿（CHBr 3）。海平面的浓度范围为2至20 ppt，对流层上层的浓度范围为0.1至1 ppt。在对流层顶上方14公里处，浓度急剧下降至低于0.01个百分点。CHBr 3占总测得的有机溴（Bro）在对流层顶的3%，并出现潜在的贡献至少9%的活性溴（Bry）在平流层空气的平均年龄小于1年。包括二溴甲烷和混合溴氯甲烷增加这些数字约10%的Bro和20%的Bry分别。在北极和中纬度平流层空气中以及平均年龄超过1.5年的气团中对CHBr 3的观测表明，这些地区的CHBr 3主要来自热带外平流层-对流层交换。
We have measured bromoform (CHBr3) in the troposphere and lower stratosphere (sea level to 17 km) from balloons, aircraft and ground stations. The concentrations ranged from 2 to 20 ppt at sea level, and 0.1 to 1 ppt in the upper troposphere. Above the tropopause the concentrations declined sharply to less than 0.01 ppt above 14 km. CHBr3 accounted for 3% of total measured organic bromine (Bro) at the extratropical tropopause, and appeared to potentially contribute at least 9% of reactive bromine (Bry) in stratospheric air of mean age less than 1 year. Inclusion of dibromomethane and the mixed bromochloromethanes increased these figures to about 10% of Bro and 20% of Bry respectively. Observations of CHBr3 in both Arctic and mid‐latitudinal stratospheric air, and in air masses with mean ages of more than 1.5 years, suggests that the CHBr3 in these locations originates predominantly from extratropical stratosphere‐troposphere exchange.