POSTER SESSION 1
15:30–17:30, Monday, September 14
Poster Session | 1 | 2 | 3 | 4 | Schedule at a Glance
ABSTRACT 1270 | POSTER 81
WHEN AND WHERE THE OCEAN BLOOMS: CHANGING PHYTOPLANKTON PHENOLOGY IN ARCTIC SEAS
Planktonic prostists form the foundation of pelagic food webs, drive carbon cycling and sustain marine productivity. Characterizing their bloom phenology is therefore essential for understanding marine ecosystem dynamics. Recent studies indicate that phytoplankton phenology is shifting globally in response to climate change, with particularly pronounced changes in Arctic and sub-Arctic regions, where environmental shifts are particularly rapid and act as sentinels of environmental change. In this study, we estimate phytoplankton bloom phenology across the Atlantic sector of the Arctic and sub-Arctic and assess spatial and temporal variability in key phenological metrics. We also explore the emergence of secondary blooms in selected regions. Chlorophyll-a concentrations (Chl-a) were derived from remote sensing reflectance data using a regionally tuned algorithm (using the bands NRRS490 and NRRS547) applied to the merged L3b ACRI GlobColour product, covering the period 2003–2024. To mitigate data gaps caused by persistent cloud cover, we computed weekly composites and applied DINEOF+ interpolation. From these data, we derived bloom start and end dates, duration, and peak Chl-a. Preliminary results highlight the marginal ice zone of the Greenland Sea as a hotspot of productivity, where the highest Chl-a was observed. In the Fram Strait, a marked dipole pattern emerges: blooms in the marginal ice zone are occurring earlier and reaching higher biomass, while open-water regions show delayed bloom initiation and reduced peak biomass. Ongoing analyses focus on disentangling the environmental drivers of these patterns, particularly the roles of sea ice dynamics and hydrographic variability in shaping regional phenological responses.
Rafael Gonçalves-Araujo, Technical University of Denmark – National Institute of Aquatic Resources, [email protected], https://orcid.org/0000-0001-8344-8326
Bodil Toftegård, National Institute of Aquatic Resources, Technical University of Denmark (DTU Aqua), [email protected]
Dominik Lis, Institute of Oceanology, Polish Academy of Sciences (IOPAN), [email protected]
Piotr Kowalczuk, Institute of Oceanology, Polish Academy of Sciences (IOPAN), [email protected]
Miroslaw Darecki, Institute of Oceanology, Polish Academy of Sciences (IOPAN), [email protected]
Poster Session | 1 | 2 | 3 | 4 | Schedule at a Glance
