Possibility of Estimating Seasonal Snow Depth Based Solely on Passive Microwave Remote Sensing on the Greenland Ice Sheet in Spring

Hiroyuki Tsutsui,Takashi Maeda

doi:10.3390/rs9060523

Abstract

Sea level rise related to the melting and thinning of the Greenland Ice Sheet (GrIS), a subject of growing concern in recent years, will eventually affect the global climate. Although the melting of snow on the GrIS is actively monitored by passive microwave remote sensing, very few studies have estimated the seasonal GrIS snow depth using this technique. In this study, to estimate seasonal snowpack on GrIS, we investigated the microwave property and optimum physical parameters. We used our microwave radiative transfer model to create a lookup table and a simple satellite retrieval algorithm to estimate seasonal snow depth on GrIS in spring, based on the microwave satellite brightness temperature from AMSR-E and AMSR2. Our research suggests there is potential for estimating snow depth based solely on GrIS passive microwave remote sensing data. We validated these estimates against in situ snow depths at several sites and compared them with the snow spatial distributions over the entire GrIS of several major products (ERA-interim, MAR ver. 5.3.1 and GLDAS-CLM) that evaluate snow depth.

Highlights

The warming of the Arctic regions and the thinning of the Greenland Ice Sheet (GrIS) have been the subject of intensive study [1,2,3]
We estimated deep snow depth in the southeast high-elevation region of the GrIS and observed this tendency in the snow accumulation of the GLDAS-CLM and monthly surface mass balance (SMB) of Modèle Atmosphèrique Règional (MAR) ver. 5.3.1, we found no such tendency in the surface water equivalent (SWE) from ERA-interim, or the daily SMB or snow height above ice from MAR ver. 5.3.1
To evaluate seasonal snow depth over the entire GrIS from the end of the midwinter season to the snowmelt season, we set the variability range based on these optimum physical parameters at the typical site (QH3 site), and calculated lookup table (LUT) for the microwave brightness temperatures

Summary

Introduction

The warming of the Arctic regions and the thinning of the Greenland Ice Sheet (GrIS) have been the subject of intensive study [1,2,3]. Many simulations have been run in recent years to estimate snow depth, which influences the melting of the GrIS ice sheet, because the snowpack blocks the heat of solar radiation from reaching the ice. Zwally et al [2] evaluated simulated precipitation and snowpack formation, and compared their modeled melt zone results using a coupled atmosphere-snow regional climate model with surface albedo measurements derived from remote sensing observations of the GrIS. To investigate the sea-level rise caused by a change in the surface mass balance (SMB) of the GrIS. They commenced their simulation using reanalysis output of the Coupled Model Intercomparison Fettweis et al [4] used the regional climate model, Modèle Atmosphèrique Règional (MAR)

Results

Discussion

Conclusion