Radiation balance of the tropical tropopause layer
Radiation balance of the tropical tropopause layer
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DOI：
10.1029/2003jd004190
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发表时间：
2004-04
影响因子：
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通讯作者：
A. Gettelman;P. Forster;M. Fujiwara;Q. Fu;H. Vömel;L. K. Gohar;Celeste M. Johanson;M. Ammerman
中科院分区：
文献类型：
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作者：
A. Gettelman;P. Forster;M. Fujiwara;Q. Fu;H. Vömel;L. K. Gohar;Celeste M. Johanson;M. Ammerman
[1]热带对流层顶层（TTL）的辐射平衡检查使用几种不同的辐射代码与标准配置文件汇编在热带地区的观测，假设晴空条件。这些代码包括详细的辐射传输模式和全球气候模式的简化代码。各种辐射活性气体的重要性进行了检查。水蒸气是TTL辐射平衡的最重要贡献者，但二氧化碳和臭氧也发挥了作用。辐射模式之间辐射加热的差异主要是由于短波辐射的处理。低于TTL的模式之间的差异是由于对水汽连续吸收的不同处理。零晴空辐射加热水平是理解空气进入平流层的重要水平，通常在15公里、125百帕和200°K（360 K位温）附近发现，这与以前的工作一致。时间和空间的变化可使该水平面变化±500 m，个别剖面与这些平均值相差±400 m（1σ）。TTL中水蒸气的增加将倾向于增加净加热为零的水平的高度，而二氧化碳或臭氧的增加将倾向于降低这一水平。TTL中的云由于云层上方长波冷却的增强而趋于增加水平。讨论了对交通的影响。
[1] The radiation balance of the tropical tropopause layer (TTL) is examined using several different radiation codes with standard profiles compiled from observations in the tropics assuming clear sky conditions. These codes include detailed radiative transfer models and simplified codes for global climate models. The importance of the various radiatively active gases are examined. Water vapor is the most important contributor to the TTL radiation balance, but carbon dioxide and ozone also play a role. Differences in radiative heating between radiation models are mostly due to treatments of shortwave radiation. Differences between models below the TTL are due to different treatments of water vapor continuum absorption. The level of zero clear sky radiative heating, a level important for understanding the transport of air into the stratosphere, is generally found near 15 km, 125 hPa and 200°K (360 K potential temperature), consistent with previous work. Changes in time and space can modify this level by ±500 m, and individual profiles vary from these averages by ±400 m (1σ). Increases in water vapor in the TTL would tend to increase the altitude of the level at which the net heating is zero, while increases in carbon dioxide or ozone would tend to decrease this level. Clouds in the TTL tend to increase the level due to enhancements in longwave cooling above clouds. The implications for transport are discussed.