Atmospheric Trace Constituents and Global Climate

ATM-9415336王伟中纽约州立大学奥尔巴尼分校标题：大气痕量成分与全球气候大气臭氧吸收入射的太阳辐射，特别是UV-B辐射，通过吸收出射的长波辐射，起到S温室气体的作用。最近的研究表明，在平流层和对流层观测到的臭氧变化可以在很大程度上扰乱辐射强迫，对气候产生重要影响。然而，存在很大的不确定性，主要与辐射传输方案以及臭氧和温度的垂直分布有关。此外，臭氧是大气中涉及几种前体(氮氧化物、碳氢化合物和一氧化碳)的化学反应形成的次要成分。这些前体的浓度取决于大气中的氧化过程，而大气中的氧化过程随时间和空间(因此气候状态)而变化很大，除了前体外，还取决于氢自由基，如OH和HO2。因此，有必要建立一个自洽的化学-辐射-动力学模式来模拟观测到的臭氧变化，并在计算辐射强迫时考虑反馈。近年来，人们还对人为来源的对流层硫酸盐气溶胶增加所造成的气候影响表示关切。预计气溶胶将通过直接向后散射太阳辐射并由于气溶胶云凝结核增加而直接增强云的反照率来冷却表面。然而，在计算的辐射强迫中存在很大的不确定性，特别是云反照率的增强及其气候效应。该项目将继续对“全球气候和大气痕量成分”进行建模和观测研究，重点是大气臭氧和硫酸盐气溶胶。PI将使用改进的辐射模型来解决与观测到的臭氧变化相关的辐射强迫计算的几个问题。他的主要工作是使用NCAR/Genesis(交互系统的通用环境和生态模拟)全球模型来研究观测到的臭氧变化和硫酸盐气溶胶增加所造成的直接气候影响。在间接气候影响方面，启动了两项探索性任务：通过与奥斯陆大学的伊瓦尔·伊萨克森教授继续合作，开发气候-化学耦合模式；通过与劳伦斯·利弗莫尔国家实验室的乔伊斯·彭纳博士合作，研究与硫酸盐气溶胶数密度增加相关的云反照率增加及其用于Genesis的参数化。这项研究之所以重要，是因为它解决了对全球变化研究至关重要的问题。

Abstract ATM-9415336 Wang, Wei-Chyung SUNY Albany Title: Atmospheric Trace Constituents and Global Climate Atmospheric ozone absorbs incoming solar radiation, in particular, the UV-B radiation and acts as s greenhouse gas by absorbing outgoing longwave radiation. Recent studies suggest that the observed ozone changes in the stratosphere and troposphere can substantially perturb the radiative forcing with important climate implications. However, large uncertainties exist, mainly related to radiative transfer schemes and vertical distributions of ozone and temperature. In addition, ozone is a secondary constituent formed by chemical reactions in the atmosphere involving several precursors (NOx, hydrocarbons and CO). The concentrations of these precursors depend on the oxidation process in the atmosphere, which varies strongly with time and space (and thus the climate state) and depends, in addition to the precursors, on the hydrogen radicals like OH and HO2. There fore, it is necessary to have a self-consistent chemistry-radiative-dynamical model to stimulate the observed ozone changes and account for the feedbacks in computing the radiative forcing. Concerns have also been raised in recent years about the climatic efffect due to increasing tropospheric sulfate aerosols of anthropogenic origin. The aerosols are expected to cool the surface by directly backscattering the solar radiation and directly enhancing the cloud albedo due to increased aerosol cloud condensation nuclei. However, large uncertainties exist in the calculated radiative forcing, in particular the enhancement of the cloud albedo, and its climatic effect. This project will continue modeling and observational studies of "global climate and atmospheric trace constituents" with focus on atmospheric ozone and sulfate aerosols. The PI will use an improved radiation model to address several issues related to the radiative forcing calculations associated with observed ozone changes. His ma in effort is to use the NCAR/GENESIS (General ENvironmental and Ecological Simulation of Interactive Systems) global model to study the direct climatic effects due to observed ozone changes and increased sulfate aerosols. For the indirect climatic effects, two exploratory tasks are initiated: the development of a coupled climate-chemistry model through continued collaboration with Prof. Ivar Isaksen at the University Oslo; and the study of increased cloud albedo associated with enhanced number density of sulfate aerosols and its parameterization for use in GENESIS through collaboration with Dr. Joyce Penner at the Lawrence Livermore National Laboratory. This research is important because it addresses questions of primary importance to global change research.