Photolysis of surface O3 and production potential of OH radicals in the atmosphere over the Tibetan Plateau
Photolysis of surface O3 and production potential of OH radicals in the atmosphere over the Tibetan Plateau
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DOI：
10.1029/2007jd008831
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发表时间：
2008-01
影响因子：
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通讯作者：
Weili Lin;T. Zhu;Yu Song;H. Zou;Mingyu Tang;Xiao-yan Tang;Jiaqi Hu
中科院分区：
文献类型：
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作者：
Weili Lin;T. Zhu;Yu Song;H. Zou;Mingyu Tang;Xiao-yan Tang;Jiaqi Hu
[1]青藏高原面积250万平方公里，平均海拔4000米左右，是北方中纬度地区最大、最高的高原。高原海拔高、纬度低、积雪面积大，地表太阳辐射强。因此，高原上空的大气很可能具有非常强的光化学活性，臭氧光解产生OH自由基的潜力很大。利用对流层紫外-可见光辐射（TUV）模型计算了天山北坡臭氧的光解速率。晴空条件下的珠穆朗玛峰（珠峰）地区。利用现场测量数据计算了大气中OH自由基的产生速率和浓度。在夏季中午，在非积雪地区，地面臭氧光解速率J（O1D）为4 - 5 × 10 − 5 s − 1，OH自由基产生速率范围为1 - 4 × 106 s − 1，OH浓度范围为106 - 107 cm − 3。在冰雪覆盖的地区，由于强降雪，J（O1D）和OH的产生速率分别高达1.3 × 10 − 4 s − 1和5.5 × 106 cm − 3 s − 1。计算了整个青藏高原的J（O1D）和OH产生量的空间分布。由于大面积被雪覆盖，冬季的O3光解速率可能等于或甚至高于夏季的速率，并可能产生与夏季一样光化学活性的大气。
[1] With an area of 2.5 million km2 and an average altitude of about 4000 m above sea level, the Tibetan Plateau is the largest and highest plateau in the mid-latitudes of the Northern Hemisphere. The high altitude, low latitude, and large snow coverage create strong surface solar radiation on the plateau. It is therefore likely that the atmosphere over the plateau is very photochemically active, with a high production potential for OH radicals by ozone photolysis. We used the Tropospheric Ultraviolet-Visible Radiation (TUV) model to calculate the photolysis rate of ozone in the Mt. Qomolangma (Everest) region under clear sky conditions. Field measurement data were used to calculate the production rate and concentration of OH radicals in the atmosphere. In the summer noon, over non-snow-covered area, surface ozone photolysis rates J(O1D) were 4–5 × 10−5 s−1, the OH radical production rate range was 1–4 × 106 s−1, and the OH concentrations range was 106 to 107 cm−3. Over areas covered with ice and snow, the J(O1D) and OH production rates could be as high as 1.3 × 10−4 s−1 and 5.5 × 106 cm−3 s−1, respectively, because of strong snow albedo. We also calculated the spatial distributions of J(O1D) and OH production over the whole Tibetan Plateau. Because of the large area covered with snow, the O3 photolysis rates in winter could be equal to or even higher than the rates in summer and might create as photochemically active an atmosphere as in summer.