Improvement of stratospheric aerosol extinction retrieval from OMPS/LP using a new aerosol model
Improvement of stratospheric aerosol extinction retrieval from OMPS/LP using a new aerosol model
复制标题
DOI：
10.5194/amt-11-6495-2018
复制
发表时间：
2018-12-06
影响因子：
3.8
通讯作者：
DeLand, Matthew
中科院分区：
文献类型：
--
作者：
Chen, Zhong;Bhartia, Pawan K.;DeLand, Matthew
臭氧绘图和剖面仪套件肢体剖面仪（OMPS/LP）自2011年10月以来一直在Suomi国家极轨合作伙伴（S-NPP）卫星上飞行。它的设计目的是以近似2公里的垂直分辨率在整个有阳光照射的地球仪上生成臭氧和气溶胶的垂直剖面图。气溶胶消光廓线的计算与米氏理论使用在675 nm处测量的辐射。业务版本1.0（V1.0）气溶胶消光反演算法假设双峰对数正态气溶胶粒径分布（ASD）的参数是通过结合现场测量的气溶胶微物理与平流层气溶胶和气体实验（SAGE II）气溶胶消光气候学。内部分析表明，这种双峰对数正态ASD不足以解释LP测量的辐射的光谱依赖性。在本文中，我们描述了一个改进的气溶胶粒径分布，指定版本1.5（V1.5），LP检索算法的推导。新的ASD使用伽马函数分布，该分布来自大气共同体气溶胶和辐射模型（CARMA）的计算结果。来自伽马函数ASD的累积分布拟合在小颗粒半径处比双峰或单峰函数与CARMA结果更好地一致。新的ASD还比V1.0 ASD更好地解释了LP测量辐射的光谱依赖性。我们发现，我们的ASD的选择对检索到的反射率的影响变化强烈的场景的底层反射率。与国际空间站（ISS）上SAGE III仪器在676 nm处检索到的并置消光剖面的初步比较显示，LP V1.5检索的一致性有了显着改善。纬向平均消光剖面在19至29公里之间的一致性在10%以内，与V1.0产品相比，同位样本的回归拟合显示出改进的相关性和减少的分散性。这一改进的协议将促进更复杂的ASD的CARMA结果，结合纬度，海拔和季节变化的气溶胶特性的发展。
The Ozone Mapping and Profiler Suite Limb Profiler (OMPS/LP) has been flying on the Suomi National Polar-orbiting Partnership (S-NPP) satellite since October 2011. It is designed to produce ozone and aerosol vertical profiles at similar to 2 km vertical resolution over the entire sunlit globe. Aerosol extinction profiles are computed with Mie theory using radiances measured at 675 nm. The operational Version 1.0 (V1.0) aerosol extinction retrieval algorithm assumes a bimodal lognormal aerosol size distribution (ASD) whose parameters were derived by combining an in situ measurement of aerosol microphysics with the Stratospheric Aerosol and Gas Experiment (SAGE II) aerosol extinction climatology. Internal analysis indicates that this bimodal lognormal ASD does not sufficiently explain the spectral dependence of LP-measured radiances. In this paper we describe the derivation of an improved aerosol size distribution, designated Version 1.5 (V1.5), for the LP retrieval algorithm. The new ASD uses a gamma function distribution that is derived from Community Aerosol and Radiation Model for Atmospheres (CARMA)-calculated results. A cumulative distribution fit derived from the gamma function ASD gives better agreement with CARMA results at small particle radii than bimodal or unimodal functions. The new ASD also explains the spectral dependence of LP-measured radiances better than the V1.0 ASD. We find that the impact of our choice of ASD on the retrieved extinctions varies strongly with the underlying reflectivity of the scene. Initial comparisons with collocated extinction profiles retrieved at 676 nm from the SAGE III instrument on the International Space Station (ISS) show a significant improvement in agreement for the LP V1.5 retrievals. Zonal mean extinction profiles agree to within 10 % between 19 and 29 km, and regression fits of collocated samples show improved correlation and reduced scatter compared to the V1.0 product. This improved agreement will motivate development of more sophisticated ASDs from CARMA results that incorporate latitude, altitude and seasonal variations in aerosol properties.