大气成分临边散射探测技术进展

Development and application of satellite-based limb scattering for atmospheric compositions

临边散射卫星遥感技术为平流层臭氧的长时序动态监测提供了有价值的数据集。自2001年搭载在Odin卫星平台上的OSIRIS(Optical Spectrograph and Infra-Red Imaging System)载荷以来,该技术领域的发展已历经20余年。后续分别搭载在ENVISAT、Suomi NPP、NOAA-21和风云三号F星(FY-3F)卫星平台上的SCIAMACHY(SCanning Imaging Absorption spectro Meter for Atmospheric CHartographY)、OMPS(Ozone Mapping and Profiler Suite)和OMS(Ozone Monitoring Suite)载荷均包含临边散射探测模块。根据载荷的波段设置、光谱分辨率、信噪比等信息,利用正向辐射传输模型和反演算法,可以获得O3廓线、NO_(2)廓线、BrO廓线及平流层气溶胶和云等信息。本文综述了星载临边散射探测技术的进展,包括临边探测载荷、正向辐射传输模型、反演算法、产品及应用4个方面,总结了临边散射技术仍存在的问题及未来的发展趋势。在正向模型方面,临边散射的模拟需要在球面大气条件下,考虑大气散射、折射、气溶胶参数化方案及仪器特性,从而实现不同切线高度的辐射模拟。在反演算法方面,需要在指向信息校正和杂散光校正的基础上,通过构建观测矢量,借助正向模型的模拟结果和观测辐射进行大气参数的信息提取。临边散射探测技术在分析平流层臭氧动态变化及其相关的氮氧化物(如NO_(2))、卤素(如BrO)、平流层云和气溶胶监测方面发挥了重要作用,本文可为中国临边探测技术的发展提供参考。

The satellite-based limb scattering measurement technique has provided valuable datasets for long-term dynamic monitoring of stratospheric ozone and ozone-related atmospheric components,such as NO_(2)and BrO.Since 2001,the development of this field has spanned more than 20 years.We summarize the principles and applications of this technique while analyzing the associated problems.This information provides a reference for the development of domestic limb scattering detection technology.Since the OSIRIS onboard the Odin satellite platform,followed by SCIAMACHY onboard the ENVISAT platform,OMPS onboard the Suomi NPP,and NOAA-21 platform,as well as OMS-L onboard the FY-3F platform,all include limb scatter detection capability.Based on the design specifications of the payloads,such as wavelength coverage,spectral resolution,signal-to-noise ratio,and instrument response function,with a Radiative Transfer Model(RTM)capable of simulating the observed limb radiance at a series of tangent heights,O3,NO_(2),and BrO profile,stratospheric aerosol,and cloud information can be retrieved from limb scattering spectra.In this study,we reviewed the development of satellite-based limb scattering technique,including instruments characteristics,RTM,inversion algorithms,products,and applications.In terms of forward models,the simulation of limb scattering needs to consider atmospheric scattering(single and multiple scattering),refraction,aerosol parameterization schemes,and instrument characteristics under full spherical atmospheric conditions.In the aspect of retrieval algorithms,the wavelength shift correction,pointing information correction,and stray light correction are needed to construct observation vectors for atmospheric parameters.The retrieved parameters have played an important role in analyzing stratospheric ozone dynamics and its related nitrogen oxides(e.g.,NO_(2))and halogen(e.g.,BrO),as well as monitoring stratospheric clouds and aerosols.Overall,limb scattering satellite remote sensing technology can provide 2—3 km vertical resolution and nearly global coverage detection capability due to its advantages in sampling frequency and observation geometry.However,limb scattering technology still has some unresolved problems.For the forward model,a fast RTM specific for limb scattering sensors is critical to meet the needs of operational application.In addition,limb scattering sensors all have the problem of pointing information error and the subjectivity of the field of view to the pollution of stray light.Accurate laboratory calibration and further analysis of the source of pointing error are effective ways to correct the influence of stray light and the registration error of tangent height.Meanwhile,accurately characterizing the aerosol characteristics and cloud top height on the limb path are also key steps to reduce inversion uncertainty.This study can facilitate the development and application of domestic limb scattering detection technology.