10:45 AM - 12:15 PM
[AHW23-P07] Estimation of parameters in an isotope-enabled GCM with data assimilation
Keywords:stable water isotopes, isotope-enabled GCMs, parameter estimation, data assimilation
This study estimates the isotopic parameters with an isotope-enabled GCM named MIROC5-iso and LETKF, a variant of the ensemble Kalman filter. Two types of isotopic observation are assimilated in the estimation: in-situ precipitation isotope observations and satellite-based ones. The method enables the estimation of spatially variable parameters in an efficient way. MIROC5-iso with the estimated parameters improved performance in simulating isotope ratios in precipitation and vapor. In the presentation, we will discuss the advantage of the estimated parameters by showing the model's performance in simulating climates different from the present, e.g., Last Glacial Maximum (LGM).