Calculation of mass discharge of the Greenland ice sheet in the Earth System Model

• Published in: Ice and Snow
• Main Authors: O. Rybak O., E. Volodin M., A. Nevecherya P., P. Morozova A., M. Кaminskaya M., О. Рыбак О., Е. Володин М., А. Невечеря П., П. Морозова А., М. Каминская М.
• Other Authors: Ф. Хёбрехтс (Свободный Университет Брюсселя), ИВМ РАН, Российский научный фонд
• Format: Article in Journal/Newspaper
• Language: Russian
• Published: IGRAS 2016
• Subjects: climate;climate model;Greenland ice sheet (GrIS);ice discharge;mass balance;mathematical model;numerical experiment; баланс массы;вычислительный эксперимент;Гренландия;климат;климатическая модель;ледниковый щит;математическая модель;сток; Greenland; Annals of Glaciology; Ice Sheet; The Cryosphere; Гренландия
• Online Access: https://ice-snow.igras.ru/jour/article/view/319; https://doi.org/10.15356/2076-6734-2016-3-293-308

Mass discharge calculation is a challenging task for the ice sheet modeling aimed at evaluation of their contribution to the global sea level rise during past interglacials, as well as one of the consequences of future climate change. In Greenland, ablation is the major source of fresh water runoff. It is approximately equal to the dynamical discharge (iceberg calving). Its share might have still larger during the past interglacials when the margins of the GrIS retreated inland. Refreezing of the melted water and its retention are two poorly known processes playing as a counterpart of melting and, thus, exerting influence on the run off. Interaction of ice sheets and climate is driven by energy and mass exchange processes and is complicated by numerous feed-backs. To study the complex of these processes, coupling of an ice sheet model and a climate model (i.e. models of the atmosphere and the ocean) in one model is required, which is often called the Earth System Model (ESM). Formalization of processes of interaction between the ice sheets and climate within the ESM requires elaboration of special techniques to deal with dramatic differences in spatial and temporal variability scales within each of three ESM’s blocks. In this paper, we focus on the method of coupling of a Greenland ice sheet model (GrISM) with the climate model INMCM having been developed in the Institute of Numerical Mathematics of Russian Academy of Sciences. Our coupling approach consists in applying of a special buffer model, which serves as an interface between GrISM and INMCM. A simple energy and water exchange model (EWBM-G) allows realistic description of surface air temperature and precipitation fields adjusted to a relief of elevation of the GrIS surface. In a series of diagnostic numerical experiments with the present-day GrIS geometry and the modeled climate we studied sensitivity of the modeled surface mass balance and run off to the key EWBM-G parameters and compared our results with similar model studies. In addition to the ...