Data assimilation with stable water isotope information: A review

Abstract

The data assimilation has been realistic with stable water isotope circulation models and spectroscopic observations for vapor isotopes. This tendency is most likely due to the rapid improvements in both the modeling and the measuring. The recent study revealed that it is possible to constrain the atmospheric fields, such as wind, air temperature, pressure, etc. by putting vapor isotope observations into the atmospheric data assimilation system. This technique would help us to more under-stand the atmospheric cycle system and/or the land-atmosphere interaction. On the other hand, the data assimilation has been frequently used in climate and paleocli-mate studies. In particular, newly developed offline data assimilation technique would drastically reduce the computation cost. All of reviewed studies in this paper did not directly use measured isotopic information, but used converted information with empirical relationship to reconstruct the climate. However, it is known that the relationship between isotope and climate is not stationary in time and space. Therefore, it will be more and more important to develop a new method directly us-ing the isotope information in the data assimilation system.