Assessing the Impact in Using Reanalysis Products to Simulate Surface Mass Balance Over the Greenland Ice Sheet

• Main Author: Kromer, Jessica Dawn
• Language: English
• Published: California State University, Los Angeles 2020
• Subjects: Arctic; Greenland; Merra; Ice Sheet
• Online Access: http://hdl.handle.net/10211.3/217012

Greenland ice sheet (GrIS) surface mass balance (SMB), and processes which influence its behavior remain an active area of research, particularly for understanding the current sea-level budget and future projections of ice sheet mass loss. Currently, various methods are employed to model the surface mass balance of the contemporary GrIS, with methodologies ranging from the use of simple positive degree day models (PDD) to computationally intensive energy balance models (EBM’s) and regional climate models (RCM’s). Many of these methodologies rely on either direct forcing’s (EBM’s and PDD) or boundary conditions (RCM’s) from atmospheric reanalysis products. Over time atmospheric reanalysis products have continued to improve with respect to horizontal resolution, allowing for direct use of fields critical for modeling and understanding the surface mass balance. Here we use a PDD model forced by temperature and precipitation from 3 atmospheric reanalysis products (ERA 5, Arctic System Reanalysis, and MERRA 2) at varying mesh resolution (30 km, 15 km, ~55 km respectively) to simulate the surface mass balance across the GrIS during the period 2000-2016. As higher resolution reanalysis products can help to better understand the contemporary GrIS surface mass balance, we highlight how variables important to the estimation of SMB vary amongst these reanalysis products and how these differences affect the SMB.