May 10, 2021
Monitoring our arctic waters and glaciers is crucial for establishing a greater understanding of global climate changes. Technologies such as remote sensing and geographic information systems are helping us to better analyze and research the changing water levels and what that means for us in the future.
IEEE Oceanic Engineering Society member Siri Jodha Khalsa is a research scientist at the National Snow and Ice Data Center and specializes in remote sensing and geographic information systems, client interface and metadata, data tool development and algorithm support. He shares his insights on remote sensing for arctic waters.
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IEEE: Why is it important to research water levels in the Arctic? What do glaciers tell us about the current state of our climate?
Siri Jodha Khalsa: Glaciers are indicators of climate because they respond to long-term trends in temperature, humidity and precipitation. Globally, glaciers have been in retreat for decades, although a few glaciers go through cycles which include a “surging” stage of advancement. Glaciers represent an important water storage mechanism in many parts of the world and their disappearance would have major impacts on the livelihoods of people living downstream.
IEEE: Can you explain how remote sensing and geographic information systems are being used to monitor glaciers and arctic ocean levels? Why are they more beneficial than other technologies?
SJK: Remote sensing is vital for monitoring conditions in the Arctic due to its inaccessibility and the harshness of the operating environment. Satellite-based remote sensing is one of the most commonly used techniques and has many advantages.
The existence of polar night, when there is no illumination of the surface by the sun, and frequent clouds mean that instruments sensing in the visible range, such as the moderate-resolution imaging spectroradiometer (MODIS) and Landsat, are limited in what they can observe. Sensors using microwave frequencies, such as Special Sensor Microwave/Imager
(SSM/I), advancing microwave scanning radiometer (AMSR) and RadarSat are most often used for monitoring the Arctic ocean, especially sea ice.
The monitoring of glaciers, in particular those that drain the ice sheets covering Greenland and Antarctica, has become a topic of great interest due to their potential to contribute to large increases in sea level. Missions carrying airborne and spaceborne sensors are regularly monitoring these outlet glaciers using remote sensing technologies, while projects like the Global Land Ice Measurements from Space are routinely cataloging the boundaries and other characteristics of glaciers worldwide.
IEEE: Can you further explain how data products such as the MODIS and the AMSR are being used in the field?
SJK: NASA’s two MODIS instruments, and similar sensors on NOAA (VIIRS) and Sentinel (OLCI) polar-orbiting spacecraft, are important for monitoring surface conditions globally because their wide viewing swath and moderate spatial resolution mean they can observe and record data for nearly every place on earth on a daily basis.
IEEE: How has IEEE’s Oceanic Engineering Society helped you understand your work better? And what exciting OES projects are coming up soon?
SJK: OES is involved in a global effort towards improving the reach of ocean sciences. Personally, OES has helped me place my work in a larger context by acquainting me with the applied aspects of remote sensing technologies in the Arctic, and by allowing me to network with other experts in the field who work on related technologies.
Apart from its flagship OCEANS conference, OES holds two conferences specifically focusing on technologies and research for monitoring polar environments – the Antarctic and Southern Ocean Forum (ASOF) and the Arctic and Northern Ocean forum (ANOF).