C044-0008
MOSAiC’s Pan Arctic Water Isotope Network: Sea ice-ocean-atmosphere interactions observed with water vapor isotope measurements from land and an icebreaker
Monday, 14 December 2020
Poster
Ben G Kopec1, Eric S Klein2, David Noone3, Hannah Bailey4, Kaisa-Riikka Mustonen4, Pete Douglas Akers5, Kyle Stephen Mattingly6, Jean-Louis Bonne7, Martin Werner8, Alun Hubbard II9 and Jeffrey M Welker1,10, (1)University of Alaska Anchorage, Department of Biological Sciences, Anchorage, AK, United States, (2)University of Alaska Anchorage, Geological Sciences, Anchorage, AK, United States, (3)University of Auckland, Department of Physics, Auckland, New Zealand, (4)University of Oulu, Ecology and Genetics Research Unit, Oulu, Finland, (5)Institut des Géosciences de l’Environnement, CRNS, Grenoble, France, (6)Rutgers University, Institute of Earth, Ocean, and Atmospheric Sciences, Piscataway, NJ, United States, (7)LSCE Laboratoire des Sciences du Climat et de l'Environnement, Gif-Sur-Yvette Cedex, France, (8)AWI, Bremerhaven, Germany, (9)CAGE - Centre for Arctic Gas Hydrate, Environment and Climate, UiT The Arctic University of Norway, Department of Geoscience, Tromsø, Norway, (10)University of Oulu & UArctic, Ecology and Genetics Research Unit, Oulu, Finland
Abstract:
One of the fundamental changes to the climate system has been the loss of sea ice across the northern high latitudes. A particularly critical response to this sea ice reduction is through its effect on ocean-atmosphere interactions. Evaporation is now possible from places and periods not possible in the past, and this has increased water vapor content around the Arctic. However, the response of ocean-atmosphere interactions to sea ice loss varies significantly over time and space. To help quantify these variations, we have established the AWIN (Arctic Water Isotope Network) that uses continuous water vapor isotope measurements (δD, δ
18O, and d-excess) at seven land-based stations from Barrow, Alaska to Ny Alesund, Svalbard and one on board the Polarstern. With a network of sites rather than a single station, we gain the advantage of tracking water vapor (from source to sink) and how it varies simultaneously across the Arctic Basin.
We use three case studies to demonstrate the roles of sea ice in regulating ocean-atmosphere interactions: 1) spring ice breakup around Thule, Greenland, 2) site-to-site vapor transport over varied sea ice, and 3) feedbacks between a storm cycle and sea ice in the central Arctic. In our Thule record (August 2017-present), we identify a consistent pattern in the d-excess annual cycle, where each spring there is a rapid reduction from high values in the cold season to low values in the warm season. This transition occurs in a matter of days and corresponds with the onset of ice breakup off the West Greenland coast, signaling the incorporation of moisture evaporated from this newly opened source. Next, we examine repeating transport patterns to identify the addition of Arctic-sourced moisture over varied sea ice coverage. Through monitoring vapor isotopic changes in air masses transported from one site to another, we quantify how much moisture is added along a given trajectory. Finally, we investigate how sea ice interacts with Arctic cyclones. Over a 10-day window in November 2019, a series of three storms entered the central Arctic basin and passed the Polarstern. We see that sea ice changes between storms influence how much local moisture is incorporated into each storm. In each of these cases, we show that the Arctic Ocean and surrounding seas are significant sources of moisture in an amplified water cycle.
