Retrieving instantaneous extinction of aerosol undetected by the CALIPSO layer detection algorithm

作者：Feiyue Mao, Ruixing Shi, Daniel Rosenfeld, Zengxin Pan, Lin Zang, Yannian Zhu, Xin Lü · 发表于：Atmospheric chemistry and physics · 年份：2022 · DOI：10.5194/acp-22-10589-2022 · 被引用次数：12 · 研究领域：Atmospheric aerosols and clouds、Atmospheric chemistry and aerosols、Atmospheric Ozone and Climate

Abstract. Aerosols significantly affect the Earth–atmosphere energy balance and climate change by acting as cloud condensation nuclei. Specifically, the susceptibility of cloud and precipitation to aerosols is stronger when aerosols are faint but tends to be saturated in polluted conditions. However, previous methodologies generally miss these faint aerosols based on instantaneous observations because they are too optically thin to be detected and are therefore usually unretrieved. This result in a large underestimation when quantifying aerosol climate impacts. Here, we focus on retrieving and verifying the instantaneous extinction of undetected faint aerosol by the CALIPSO layer detection algorithm on a global scale. Using the observations during the Stratospheric Aerosol and Gas Experiment III on the International Space Station (SAGE III/ISS) as constraints, the lidar ratios of undetected faint aerosol are estimated with a global median of 42.2 and 24.5 sr at the stratosphere and the troposphere, respectively. The retrieved extinction of undetected aerosol during night-time shows good agreement with the independent 12-month SAGE III/ISS product on a 1∘ average. The corresponding correlation coefficient and averaged normalized root-mean-square error are 0.66 % and 100.6 %, respectively. The minimum retrieved extinction coefficients can be extended to 10−3 and 10−4 km−1 with an uncertainty of 35 % and 125 % during night-time, respectively. The CALIPSO retrieval during daytime...