硝酸盐气溶胶光学厚度和有效辐射强迫的模拟研究

发布时间：2018-10-12 07:53

【摘要】：在过去二十多年里,国内外对硫酸盐气溶胶做了大量研究,对它在大气中的排放、含量、光学特征和辐射强迫都有了深入的认识。由于硝酸盐气溶胶在大气中平均含量比硫酸盐低很多,因此以往对硝酸盐的研究没有给予重视。然而,近年来的研究表明,硝酸盐气溶胶的散射性质在某些波段强于硫酸盐;同时,由于未来对人为硫酸盐前体物的减排,硫酸盐气溶胶会大大减少,而硝酸盐气溶胶的排放却迅速增加,其在总人为气溶胶所占比例越来越高,未来硝酸盐气溶胶的辐射强迫可能会超过硫酸盐气溶胶,同时在地区范围内和季节尺度上成为重要的辐射强迫和气候影响因子。因此,为了深入了解硝酸盐气溶胶的浓度与辐射强迫,本文利用中国气象局国家气候中心的新一代气溶胶大气化学—气候模式在线耦合模式系统BCC_AGCM_CUACE2.0分析了硝酸盐气溶胶的排放及其在大气中浓度的分布与变化、光学厚度分布特征和辐射强迫。主要结论如下:(1)对全球而言,1850-2010年硝酸盐气溶胶的浓度增加了约1.43 mg/m~2,主要分布在东亚地区、欧洲地区、南亚少部地区和北美东部,其中东亚地区增加尤为明显,最大值约为19.24 mg/m~2。1850-2100年,硝酸盐气溶胶的增量大约在0.45~1.04 mg/m~2之间,增量高值区主要分布在东亚地区和欧洲地区。从季节平均来看,冬季硝酸盐气溶胶增加显著。(2)全球平均来看,1850~2010年,硝酸盐气溶胶光学厚度增加约0.005;1850~2100年,硝酸盐气溶胶光学厚度的增量大约在0.001~0.003之间。硝酸盐气溶胶光学厚度与其柱浓度有很好的对应关系。(3)自1850年以来,至2010年硝酸盐由于气溶胶-辐射相互作用产生的辐射强迫(RFari)约为-0.14 W/m~2,高值区主要分布在欧洲、东亚、南亚和北美地区,到了2100年,其RFari在-0.044~-0.099 W/m~2之间。从季节分布来看,硝酸盐RFari最大值可能出现在冬季或夏季(随不同的排放情景而变化),这是因为影响硝酸盐RFari的不仅有硝酸盐的柱浓度,还包括太阳高度角、相对湿度、云量以及地表反照率等因素。(4)自1850年以来,至2010年硝酸盐由于气溶胶-辐射相互作用产生的有效辐射强迫(ERFari)约为-0.26W/m~2,大于其RFari;至2100年,硝酸盐气溶胶的ERFari将在-0.054~-0.15 W/m~2之间。
[Abstract]:In the past twenty years, a great deal of research has been done on sulfate aerosol in China and abroad, and its emission, content, optical characteristics and radiative forcing in the atmosphere have been deeply understood. Since the average content of nitrate aerosol in the atmosphere is much lower than that of sulfate, no attention has been paid to the study of nitrate in the past. However, recent studies have shown that the scattering properties of nitrate aerosols are stronger than those of sulphates in some wavelengths, and that sulfate aerosols will be significantly reduced as a result of future reductions in anthropogenic sulfate precursors, However, the emission of nitrate aerosol is increasing rapidly, and the proportion of nitrate aerosol is increasing. In the future, the radiative forcing of nitrate aerosol may exceed that of sulfate aerosol. At the same time, it has become an important radiative forcing and climate influence factor in regional and seasonal scale. Therefore, in order to gain a better understanding of nitrate aerosol concentration and radiation forcing, In this paper, the emission of nitrate aerosol and the distribution and variation of nitrate aerosol concentration in the atmosphere are analyzed by using the new generation online coupled model system of aerosol atmospheric chemistry and climate model (BCC_AGCM_CUACE2.0) of the National Climate Center of China Meteorological Administration. Optical thickness distribution and radiation forcing. The main conclusions are as follows: (1) for the whole world, the concentration of nitrate aerosols increased by about 1. 43 mg/m~2, from 1850 to 2010, mainly in East Asia, Europe, South Asia and East America, especially in East Asia. The maximum value is about 19.24 mg/m~2.1850-2100, and the increment of nitrate aerosol is about 0.45 ~ 1.04 mg/m~2. The high increment region is mainly distributed in East Asia and Europe. In terms of seasonal average, nitrate aerosol increased significantly in winter. (2) from 1850 to 2010, the optical thickness of nitrate aerosol increased about 0.005 ~ 1850 ~ 2100, and the increment of nitrate aerosol optical thickness was about 0.001 ~ 0.003. The optical thickness of nitrate aerosol has a good correlation with its column concentration. (3) from 1850 to 2010, the radiative forcing (RFari) of nitrate due to aerosol radiation interaction is about -0.14 W / m ~ (2), and the high value region is mainly distributed in Europe and East Asia. In South Asia and North America, by 2100, its RFari was-0. 044-0. 099 W/m~2. In terms of seasonal distribution, the maximum value of nitrate RFari may occur in winter or summer (varying with different emission scenarios), because nitrate RFari is affected not only by nitrate column concentration, but also by solar height angle, relative humidity, Cloud cover and surface albedo. (4) from 1850 to 2010, the effective radiation forcing (ERFari) of nitrate due to aerosol radiation interaction is about -0.26 W / m ~ 2, which is larger than its RFari; to 2100, and the ERFari of nitrate aerosol will be -0.054 ~ 0.15 W/m~2.
【学位授予单位】：中国气象科学研究院
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X513

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