As arctic temperatures are on the rise due to climate change and the land area used to track water in arctic landscapes has been decreasing fast, researchers have been looking for new methods to obtain data on the movement of surface water in the arctic. Understanding the movement of surface water is crucial to obtaining accurate data on environmental impacts of climate change. One potential solution to tracking the location and paths of water in the arctic is using satellite-based remote sensing. Dr Tamlin Pavelsky gave a seminar at IHRR on observing arctic hydrology using satellite remote sensing techniques from space. While satellite-based remote sensing is still at an early stage, it could potentially play a large role in how we understand the water cycle in the arctic and throughout the world in much greater detail.
Rising temperatures in the arctic will likely continue to decrease ice sheet cover at an accelerated rate. Lakes in the arctic are also disappearing due to drainage caused by the melting of the permafrost layer along lake bottoms. If researchers are to understand these impacts on ice and water bodies in the arctic, a variety of remote sensing techniques could substantially improve our knowledge of the movement of water in the arctic.
Some remote sensing techniques use microwave sensors to avoid distortion due to cloud cover, while others use infrared light. Some of the best satellite-based remote sensing techniques use a variety of different wavelengths of light to produce detailed images. One technique that has worked well in tracking the movement of water in rivers and lakes is SPOT imagery which has been used to map sediment carried by water. If sediments can be mapped then an accurate picture of the connections of river systems to lakes can be developed. Another method called MODIS (Moderate Resolution Imaging Spectroradiometer), developed by NASA, uses 36 different wavelengths ranging from visible light to infrared. It provides consistent data over long or short time spans. Yet another satellite-imaging project by NASA for tracking surface water is SWOT (Surface Water and Ocean Topography) that will utilise data taken from the land and remote sensing.
A major obstacle to overcome for satellite-based remote sensing techniques is tracking wetlands, which are extremely difficult to map remotely due to the lack of surface water. Since there is little to no water on the surface of wetlands, the area does not reflect enough light suitable for taking images of wetlands using remote sensing. Developing an accurate method to track wetlands in the arctic is highly important as they store most of its water and is considered by some to be the ‘holy grail’ of arctic hydrology.
Listen to Dr Tamlin Pavelsky’s seminar at IHRR here: Observing Arctic hydrology: The view from Space