Mass balance, dynamics, and climate of the central Dronning Maud Land coast, East Antarctica

The Antarctic Ice Sheet is not a deadly cold, silent place. Its coastal region where the ice meets ocean can rapidly change in decades or in centuries, but such features in Dronning Maud Land (DML), a Norwegian claim territory in Antarctica, remain largely unknown. This project collaborates with India's Antarctic program to investigate floating ice shelves and adjacent grounded ice in central DML using logistics support from India's Maitri Station. Norway's Troll Station is far away from the study area so the collaboration with India gives the unique opportunity for Norway to study central DML. We conducted two Norwegian-Indian field campaigns in November-December 2016 and 2017, and our Indian collaborators conducted a third campaign in November-December 2018 with technical support from us. We successfully measured bed topography under the ice, snow accumulation over the last three decades, present ice-flow fields, oceanic basal melting under the ice shelf, and changes of ice thickness of the ice shelves and ice rises that are locally grounded and surrounded by ice shelves. Our Indian collaborators collected three ice cores from the ice rises. We hosted an Indian researcher for six weeks in autumn 2018 to conduct joint analysis that use both radar and ice-core data. Combining these studies, two peer-review articles were published, one article is currently in a revision stage, and two more articles are in preparation primarily from glaciological work of the MADICE, which Norway was responsible for. More publicaitons are expected primarily from ice core studies led by India. Our results show that this region has been relatively stable in the past millennium. Ice cores from two sites at different elevations show distinct characteristics with which we are able to reconstruct both paleoclimate and local surface melting history. Surface mass balance mapped over the ice shelf shows a strong spatial gradient, which has been rather uniform over the past three decades. Basal melting under the ice shelf successfully documented over almost 2 years, shows that the melt rate varies seasonally near the calving front but is low and more uniform at a landward site. On the top of these successful research activities, we organized the first summer school in India on Antarctic climate variability and ice dynamics in May 2017. Together with NRK's news, web articles, and Facebook pages, we have made excellent achievements not only in research but also education and outreach. We planned to make the fourth field season to investigate Verbljud and Kamelryggen ice rises, which were not surveyed due to bad weather in the second field season, and provide maintenance service to the continuous radar sites on the ice shelf. Because of covid we postponed this fieldwork for one year to 2021-22 season.

Beyond published and in preparation publications, this project generated a strong foundation for future India-Norway collaborations in Antarctica, developed glaciology capacity in India through PhD and postdoc training, and more generally the summer school.

East Antarctica has been believed to be much more stable than the rapidly changing West Antarctica, but recent studies have questioned this conventional belief. The largely-unknown Dronning Maud Land (DML) coast in East Antarctica has a chain of small ice shelves that have distinct environmental settings, suggesting that individual regions have different responses to the ongoing climate change. The project will combine satellite remote sensing, geophysical field measurements and ice cores to investigate mass balance, dynamics, and climate of an inter-connected system of the grounded features (ice rises) and the Nivlisen and Lazarev Ice Shelves near India's Maitri Station in the central DML. This region is out of practical logistics coverage from Troll Station. Collaboration with India and use of their station bring the unique opportunity for Norway to transfer our experiences developed in other DML regions to this unexplored region. The project will start in January 2016 and take four years to complete. Major activities include two larger India-Norway joint field campaigns each in the 2016-17 and 17-18 Antarctic seasons and smaller India-only field campaigns in the 2017-18 and following seasons. All of these field activities will be made from Maitri Station relying on Indian logistics with Norwegian support as well, and provide excellent training opportunities for early-career scientists in India and Norway. The project will organize a summer school in early 2017 for postdoctoral fellows and graduate students. These networking activities will facilitate the long-term collaboration between the two nations.