Global-scale transport of carbon dioxide in the troposphere
Global-scale transport of carbon dioxide in the troposphere
复制标题
DOI：
10.1029/2007jd009557
复制
发表时间：
2008-08
影响因子：
--
通讯作者：
K. Miyazaki;P. Patra;M. Takigawa;T. Iwasaki;T. Nakazawa
中科院分区：
文献类型：
--
作者：
K. Miyazaki;P. Patra;M. Takigawa;T. Iwasaki;T. Nakazawa
采用大气输送模式研究了不同尺度的大气输送过程（拉格朗日平均运动、大尺度涡旋、参数化垂直扩散和对流输送）在对流层二氧化碳时空分布中的作用。用质量加权等熵纬向平均分析了平均和涡旋输送。我们发现在两个半球的温带和热带之间对流层CO2分布的主要输送过程存在一些差异。(1)在北温带秋春季，人为源和生物圈源排放的CO2通过准等熵涡混合与斜压波相结合的方式被抬升和分散，并在温带低等熵对流层（300K以下的“冷袋”）积累。(2)高co2空气通过低空平均经向流从北温带输送到热带。在寒带冬春期间，它与热带植被通过深对流和非绝热涡旋释放的二氧化碳一起被抬升。(3)夏季在中纬度北部，生物圈吸收产生的低混合比CO2通过对流上升到对流层上层，与低纬度地区强烈隔离。(4)北半球和热带地区排放的CO2由于寒带冬春季的涡旋混合和寒带夏季Hadley环流的平均发散流，通过热带对流层上层输送到南半球。(5)在南半球，寒带春秋季节对流层上层南向平流形成了一个上升的CO2梯度。
[1] An atmospheric transport model was used to examine the roles of variously scaled atmospheric transport processes (Lagrangian mean motions, large-scale eddies, and parameterized vertical diffusion and convective transport) in the spatiotemporal distributions of tropospheric carbon dioxide (CO2). The mean and eddy transports were analyzed using the mass-weighted isentropic zonal mean. We found several differences in the dominant transport processes for tropospheric CO2 distributions between the extratropics of both hemispheres and the tropics. (1) In the northern extratropics in boreal autumn to spring, CO2 emitted by anthropogenic and biospheric sources is uplifted and dispersed through quasi-isentropic eddy mixing associated with baroclinic waves and accumulates in the extratropical low-isentropic troposphere (in “cold pocket” below 300K). (2) High-CO2 air is transported from the northern extratropics into the tropics through low-level mean meridional flow. It is uplifted together with CO2 emitted by tropical vegetation through deep convection and diabatic eddies in the tropics during boreal winter to spring. (3) During summer at the northern midlatitudes, the low mixing ratio of CO2 produced by biospheric uptake is uplifted into the upper troposphere by convection and is strongly isolated from the lower latitudes. (4) The CO2 emitted in the Northern Hemisphere and the tropics is transported into the Southern Hemisphere via the tropical upper troposphere due to eddy mixing during boreal winter to spring and mean divergent flow of Hadley circulation during boreal summer. (5) In the Southern Hemisphere, an upward gradient of CO2 forms by upper tropospheric southward advection during boreal spring-autumn.