Monitoring ice break-up on the Mackenzie River using MODIS data

P Muhammad,K.-K Kang,C Duguay

doi:10.5194/tc-10-569-2016

Abstract

Abstract. The aim of this study was to develop an approach for estimating ice break-up dates on the Mackenzie River (MR) using more than a decade of MODIS Level 3 500 m snow products (MOD/MYD10A1), complemented with 250 m Level 1B radiance products (MOD/MYD02QKM) from the Terra and Aqua satellite platforms. The analysis showed break-up began on average between days of year (DOYs) 115 and 125 and ended between DOYs 145 and 155 over 13 ice seasons (2001–2013), resulting in an average melt duration of ca. 30–40 days. Thermal processes were more important in driving ice break-up south of the MR confluence with the Liard River, while dynamically driven break-up was more important north of the Liard. A comparison of the timing of ice disappearance with snow disappearance from surrounding land areas of the MR with MODIS Level 3 snow products showed varying relationships along the river. Ice-off and snow-off timing were in sync north of the MR–Liard River confluence and over sections of the MR before it enters the Mackenzie Delta, but ice disappeared much later than snow on land in regions where thermal ice break-up processes dominated. MODIS observations revealed that channel morphology is a more important control of ice break-up patterns than previously believed with ice runs on the MR strongly influenced by channel morphology (islands and bars, confluences and channel constriction). Ice velocity estimates from feature tracking were able to be made in 2008 and 2010 and yielded 3–4-day average ice velocities of 1.21 and 1.84 m s−1 respectively, which is in agreement with estimates from previous studies. These preliminary results confirm the utility of daily MODIS data for monitoring ice break-up processes along the Mackenzie River. The addition of optical and synthetic aperture radar data from recent and upcoming satellite missions (e.g. Sentinel-1/2/3 and RADARSAT Constellation) would improve the monitoring of ice break-up in narrower sections of the MR.

Highlights

The Mackenzie River basin (MRB) is the largest in Canada and is subject to one of the most important annual hydrologic events
The geographical area of this study focuses on the Mackenzie River extending from the western end of Great Slave Lake (61.36◦ N, 118.4◦ W) to the Mackenzie Delta (67.62◦ N, 134.15◦ W) (Fig. 1)
River morphology acted as an important spatial control determining the type of ice break-up process and ice run

Summary

Introduction

The Mackenzie River basin (MRB) is the largest in Canada and is subject to one of the most important annual hydrologic events. Ice break-up is defined as a process with specific dates identifying key events in space and time between the onset of melt and the complete disappearance of ice in the river. Investigations of river regimes in high-latitude countries including Canada, the United States, Russia, Sweden and Finland have a long history related to their ice monitoring (Lenormand et al, 2002). This is important as ice freeze-up and break-up records serve as climate proxies responding to changing air temperature patterns (Magnuson et al, 2000). There is a gap in knowledge when attempting to understand all associated hydrologic parameters due to their highly dynamic nature (Beltaos et al, 2011)

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Discussion

Conclusion