Time:
15:00-16:00 UTC+2, Tuesday, 14 October 2025
Online
Host:
Aotearoa Blue Ocean Research & Leibniz Institute for Baltic Sea Research Warnemünde
Conveners:
Karin Kvale (Aotearoa Blue Ocean Research, New Zealand)Damian L. Arévalo-Martínez (Leibniz Institute for Baltic Sea Research Warnemünde, Germany)

Speakers
Josefa Verdugo
Aarhus University, Denmark
Title: How meltwater shapes under-ice pCO₂ in the Arctic: from melt onset to melt pond drainage
Abstract: Arctic summer sea ice is shrinking, altering air–sea gas exchange—especially as meltwater freshens the surface ocean. To examine what this means for carbon dioxide (CO₂), we monitored a High-Arctic fjord in Northeast Greenland across the melt season, from early thaw to melt-pond drainage. In this talk, we draw on under-ice, high-frequency observations to unpack the key melt-season processes and how they regulate partial pressure of carbon dioxide (pCO₂) beneath the sea ice.
John Prytherch
Uppsala University, Sweden
Title: Constraining polar air-sea gas exchange with in situ flux observations
Abstract: Numerical models face persistent uncertainties in representing air-sea gas exchange in the presence of sea ice. Sea ice acts as a barrier to exchange while also influencing the exchange through its heterogeneous impacts on the physical, chemical and biological properties of the upper ocean. In summer months ephemeral meltwater layers present a particular challenge to both model representation, and to observations from ship-borne systems sampling below the stratification. Recent progress on understanding polar gas exchange and directions for future research are explored using in situ observations from several Arctic field campaigns.