Discriminating Types Ia and Ib polar stratospheric clouds in POAM satellite data
Discriminating Types Ia and Ib polar stratospheric clouds in POAM satellite data
复制标题
POAM 卫星数据中 Ia 型和 Ib 型极地平流层云的判别
DOI：
--
复制
发表时间：
2002
期刊：
影响因子：
--
通讯作者：
David P. Dempsey
中科院分区：
文献类型：
--
作者：
A. Strawa;K. Drdla;M. Fromm;R. Pueschel;K. Hoppel;E. Browell;P. Hamill;David P. Dempsey
[1]本文介绍了一种从极区臭氧和气溶胶测量（POAM）卫星掩星测量的气溶胶消光系数中鉴别Ia和Ib型极区平流层云（PSC）的方法。通过对结果进行几次统计检验，并利用平流层气溶胶和气体实验（SAGE）三臭氧损失和验证实验/第三次欧洲平流层臭氧实验II（SOLVE/THESEO 2000）期间进行的差分吸收激光雷达和臭氧激光雷达实验（OLEX）激光雷达观测，对该方法进行了验证。Ia型PSC被认为是由含有硝酸的大颗粒组成，这些颗粒将从平流层中沉淀出来，导致反硝化作用并促进臭氧消耗。Ib型PSC被认为要小得多，不会从平流层中沉淀出来。区分这两种类型的PSC具有重要意义，因为它将有助于更好地了解当今的臭氧消耗情况，并利用可从卫星获得的更连续的时间覆盖范围和更大的面积覆盖范围来预测PSC的命运和影响。该方法是可能的POAM观测的字符时，绘制为归一化消光与波长的依赖性。随着灭绝的增加，对Ia型和Ib型PSC的观察出现分歧。在过冷三元溶液（STS）和硝酸三水合物（NAT）颗粒形成的理想化模拟中也观察到这种行为，认为它们分别构成Ib型和Ia型PSC。分析POAM观测从1999/2000年北极冬季使用PSC歧视算法显示，PSC观测的数量在1月达到峰值。在11月，12月和1月，Ia型与Ib型PSC的比例约为3。2月和3月，这一比例约为0.3。Ia型PSC的平均高度比Ib型下降得更多，特别是在春季，Ia型观测值比Ib型观测值低2-3 km。这与1999/2000年冬季的反硝化观测结果一致。PSC鉴别算法适用于两个半球以前的冬季，也适用于SAGE III观测。这将允许更广泛的研究在1999/2000年北极冬季观察到的PSC的一些功能的统计意义。我们相信，目前的方法分析卫星数据来区分第一类PSC将是非常有用的研究PSC和臭氧消耗。
[1] A method for discriminating Types Ia and Ib Polar Stratospheric Clouds (PSCs) from Polar Ozone and Aerosol Measurement (POAM) satellite occultation measurements of aerosol extinction coefficient is described. The method has been validated by applying several statistical tests to the results and by using Differential Absorption Lidar (DIAL) and Ozone Lidar Experiment (OLEX) lidar observations made during Stratospheric Aerosol and Gas Experiment (SAGE) III Ozone Loss and Validation Experiment/Third European Stratospheric Experiment on Ozone II (SOLVE/THESEO 2000). Type Ia PSCs are believed to be composed of large nitric-acid-containing particles that will sediment out of the stratosphere, causing denitrification and facilitating ozone depletion. Type Ib PSCs are believed to be much smaller and will not sediment out of the stratosphere. Discriminating between these two types of PSCs is significant because it will permit a better understanding of ozone depletion today and predict the fate and effect of PSCs using the more continuous temporal coverage and larger areal coverage that can be obtained from satellites. The method is made possible by the character of POAM observations when plotted as normalized extinction versus wavelength dependence. As the extinction increases, observations of Types Ia and Ib PSCs bifurcate. This behavior is also observed in idealized simulations of the formation of Supercooled Ternary Solutions (STS) and nitric acid trihydrate (NAT) particles, which are believed to make up Types Ib and Ia PSCs, respectively. Analysis of POAM observations from the 1999/2000 Arctic winter using the PSC discrimination algorithm revealed that the number of PSC observations peaked in January. In November, December, and January, the ratio of Type Ia to Ib PSCs was about 3. In February and March, this ratio was about 0.3. The average altitude of Type Ia PSCs descended more than the Type Ib, especially in the spring where the Type Ia observations were 2–3 km below the Type Ib observations. This is consistent with observations of denitrification during the 1999/2000 winter. The PSC discrimination algorithm is applicable to previous winters in both hemispheres and will work with SAGE III observations as well. This will permit a more extensive study of the statistical significance of some features of the PSCs observed during the 1999/2000 Arctic winter. It is our belief that the present method of analyzing satellite data to discriminate Type I PSCs will be of great utility in the study of PSCs and ozone depletion.