[A-CG38] Satellite Earth Environment Observation

[ACG38-12] Quantitative Evaluation of Smile Effect on the EarthCARE/MSI Cloud Product

*Minrui Wang¹, Takashi Nakajima², Woosub Roh³, Masaki Satoh³, Takuji Kubota⁴ (1.Tokai University Research and Information Center, 2.Tokai University, School of Information Science & Technology, Dept. of Human & Information Science, 3.AORI, the university of Tokyo, 4.Earth Observation Research Center,Japan Aerospace Exploration Agency)

Keywords:Satellite obversion, Cloud properties retrieval, EarthCARE, Smile effect, NICAM/J-Sim simulator

During recent works, we have found a situation that MSI sensitivity coefficient could largely shift (Smile Effect) among some specific wavelengths (band1 and band3).

To evaluate the impact of the smile effect on cloud retrieval products, we chose four detector pixels from band1 and band3 (as well as the nadir pixel for reference) in order to elucidate how much the variation of sensitivity coefficient affects the optical thickness and effective radius of cloud droplet, by using Comprehensive Analysis Program for Cloud Optical Measurement (CAPCOM).

For the Typical case of shallow water clouds (τ=8, re=8μm), the smile effect for the cloud retrieval is not significant for most cases (up to 6% of error).
For the Typical case of deep convective clouds (τ=8, re=40μm), the smile effect for the cloud retrieval is even less significant for most cases (up to 4% of error).

Meanwhile, in order to see how the smile effect affects actual satellite observation scenes, we select a typical shallow water cloud scene and a deep convective cloud scene from NICAM/J-Sim simulation data, then get the retrieval of cloud properties using CAPCOM. The result matched quite well with it in the forward radiation simulation, indicating that the error from the smile effect is within 10% for most cases.