High-resolution ensemble retrieval of cloud properties for all-day based on geostationary satellite
Haixia Xiao, Feng Zhang, Lingxiao Wang, Baoxiang Pan, Yannian Zhu, Minghuai Wang, Wenwen Li, Bin Guo, Jun Li
TL;DR
CloudDiff introduces a conditional diffusion-model framework for all-day, high-resolution retrieval of cloud properties from geostationary infrared data, enabling ensemble sampling to quantify uncertainty. Trained on Himawari-8/AHI 2 km TIR data and MODIS targets, CloudDiff delivers 1 km cloud-property maps for $COT$, $CER$, $CTH$, and $CLP$, with 30-sample ensembles that improve accuracy and reliability over deterministic baselines. Evaluations against MODIS and CALIPSO show strong performance in CLP classification and cloud-top properties, and a Typhoon In-Fa case demonstrates the method’s capacity to capture both sharp local structure and uncertainty in extreme events. The study discusses limitations due to MODIS biases, suggests physics-informed constraints and transfer learning, and outlines extensions to other geostationary satellites for broader applicability in cloud remote sensing and severe-weather analysis.
Abstract
Clouds play a critical role in Earth's hydrological and energy cycles, and accurately representing their properties is essential for effective numerical modeling and weather forecasting. Machine learning methods have been widely used for cloud property retrieval; however, most existing techniques are deterministic and do not incorporate uncertainty quantification. Generative machine learning has made significant advances in various domains, including natural language processing, image generation, and notably weather forecasting, where it has enabled ensemble predictions and the quantification of forecast uncertainty. This ability to quantify uncertainty offers valuable opportunities for cloud remote sensing. In this study, we propose a novel cloud property retrieval method, CloudDiff, based on a generative diffusion model. By leveraging thermal infrared observations from the Himawari-8 Advanced Himawari Imager (AHI), CloudDiff generates high spatiotemporal resolution cloud properties for both daytime and nighttime conditions, increasing the resolution of Himawari-8/AHI cloud retrievals from 2 km to 1 km. Unlike deterministic retrieval methods, CloudDiff generates multiple samples from the underlying probability distribution, allowing for a diverse range of plausible retrievals and taking steps towards providing uncertainty assessment. Additionally, CloudDiff produces sharper samples and better captures fine local features, enhancing the precision of cloud property retrieval. By averaging over the ensemble of generated samples, we demonstrate that both the accuracy and reliability of the retrievals are significantly improved. These high-resolution cloud properties have been successfully applied to analyze extreme weather events, such as typhoons, providing potentially valuable insights into atmospheric processes.
