Progress in Hydrological Modeling over High Latitudes: Under Arctic Climate System Study (ACSYS)

Abstract

We review achievements in hydrological modeling over high latitudes during ACSYS, including development and improvement of land surface schemes in representing cold processes, large-scale hydrological modeling over high-latitude river basins, and estimates of freshwater river infl ow to the Arctic Ocean. ACSYS hydrological modeling efforts were closely linked to the GEWEX continental-scale experiments (CSEs) and to the Project for Intercomparison of Land-Surface Parameterization Schemes (PILPS). Results in this review are mainly from PILPS 2(e), MAGS, BALTEX, GAME-Siberia (the latter three of which are CSEs), and other studies related to ACSYS. Based on these achievements from the 10 years efforts, the ACSYS scientifi c strategy for hydrology, which included adaptation of macroscale hydrological modes developed in the framework of GEWEX to Arctic (high-latitude) climate conditions and development of physical (conceptual) or parametric mesoscale hydrologic models for selected river catchments within the Arctic region, was implemented more or less as envisaged in the ACSYS Implementation Plan. In spite of major advances in high-latitude hydrological mod- eling during the ACSYS era, there remain important problems in parameterization of snow, frost, and lake/wetlands cold processes within climate and hydrology models and in linkages between atmospheric and hydrological models. D.