This new way of dealing with dazzle from ponds of meltwater also provides a significant step forward for ESA in the development on the future Copernicus Polar Ice and Snow Topography Altimeter, CRISTAL.Ĭarrying a dual-frequency radar altimeter and microwave radiometer, CRISTAL will measure and monitor sea-ice thickness and overlying snow depth. ![]() "We can also predict whether there will be ice or not at a given location in September, by measuring the ice thickness in May.” This increases safety for ships and fishing boats," added Dr Landy. “Using the new satellite data, we are finally able to make sea-ice forecasts informed by the ice thickness, not only for the winter, but also for the summer. Measuring the thickness of sea ice in the Arctic for validation The Norwegian Meteorological Institute provides sea-ice forecasts for the Arctic but have lacked pan-Arctic observations of sea-ice thickness through the summer months. Nevertheless, before setting course, ships need accurate information on where the ice is and how thick it is. Melting summer ice has meant that shipping has increased significantly in recent years, particularly in the Barents Sea and near Svalbard. For example, they lead to safer Arctic passage for maritime traffic, particularly in summer. “When we use the new ice-thickness data in advanced numerical prediction models, it will improve both our short-term forecasts for the weather at the mid-latitudes and the long-term forecasts that show what climate we will have in the future.”Īs well as advancing climate science, these new findings will also have important practical uses. Year-round sea-ice thickness from CryoSatĪccording to Dr Michel Tsamados from University College London the findings are of great importance for our understanding of the weather and the climate. Our new observations confirm that over the past decade, the volume of summer sea-ice has been as low as predicted by the models.” “Climate models predict that the Arctic Ocean has lost around three-quarters of its summer sea-ice volume since the 1980s. The data have revealed that sea-ice volume shrinks by 80% each summer in the Arctic, from around 23 000 cubic km at the end of winter to around 4000 km at the end of summer. “By comparing the new satellite data with in-situ observations from fieldwork campaigns in the Arctic, we discovered that CryoSat could indeed measure the sea-ice thickness accurately during summer. Their results, published today in Nature, describe how they harnessed artificial intelligence and applied it to CryoSat’s data to yield the first pan-Arctic, all-year, decade-long, twice-monthly sea-ice thickness record for 2011–2020.ĭr Landy explained, “Our international team used artificial intelligence techniques to check whether CryoSat was looking at the melting sea-ice floes or the ocean surface between floes, then we used radar model simulations to ensure CryoSat was measuring the thickness of the sea ice correctly.” Having confidence in satellite data is absolutely key to climate science research so, funded initially by ESA’s Living Planet Fellowship Programme and then by the UK Natural Environment Research Council and the Research Council of Norway, a team lead by Dr Landy looked into how this issue of dazzle could be solved. We need knowledge about the thickness of the sea ice, both to reduce safety risks for businesses and shipping, but also to make forecasts for the future climate.”ĬryoSat carries a specialised radar altimeter that measures the height of ice protruding above the water, and from this ice thickness can be calculated. Jack Landy, from the UiT Arctic University of Norway, said, “Arctic ice is melting faster than ever. ![]() To understand exactly how much ice the Arctic Ocean is losing, measures of both ice extent and ice thickness are needed to work out the actual loss in terms of volume. ![]() It also supports native communities and is vital for wildlife above and below the water. For example, its white surface reflects far more sunlight back to space than the dark ocean, it acts as insulation between the ocean waters and the air, and it helps drive global ocean circulation patterns. As one of the most dynamic components of Earth's climate system, sea ice naturally waxes and wanes with the seasons, but the overall trend is one of rapid decline as a result of climate warming.įloating ice not only plays a fundamental role in the polar environment but also in the global climate.
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