2026-09-04 東京大学
本研究で用いたデータ同化システムの概略図
＜関連情報＞
気象予報の改善における水蒸気同位体の重要性 The significance of water vapor isotopes in improving weather prediction
Kinya Toride,Kei Yoshimura,Matthias Schneider,Christopher Diekmann,Farahnaz Khosrawi,Benjamin Ertl & Hayoung Bong
Communications Earth & Environment Published:03 September 2026
DOI:https://doi.org/10.1038/s43247-026-03917-x
Abstract
Water vapor isotopes carry the integrated history of evaporation, condensation, mixing, and transport. Although previous studies have shown potential to improve forecasts under controlled conditions, real-world applications have been limited by systematic biases in both models and satellite retrievals arising from sparse measurements in the free troposphere. Here we assimilate mid‑tropospheric δD retrievals (peak sensitivity ~4.2 km) from the Infrared Atmospheric Sounding Interferometer into the Isotope‑incorporated Global Spectral Model and evaluate the added value beyond co‑assimilated temperature and specific humidity with identical spatial and temporal coverage. Assimilating δD improves 0–120 h forecasts of wind, temperature, specific humidity, and geopotential height, with the largest gains in the midlatitudes; heavy‑precipitation skill also increases for thresholds >3 mm per 6 h. Demonstrated in a coarse‑resolution configuration with limited observations, the results indicate that isotopic information strengthens transport tracking and hydrological constraints, motivating evaluation in operational high‑resolution forecasting systems.
