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Although standard statistical methods and climate models can simulate and predict sea-ice changes well, it is still very hard to distinguish some direct and robust factors associated with sea-ice changes from its internal variability and other noises. Here, with long-term observations (38 years from 1980 to 2017), we apply the causal effect networks algorithm to explore the direct precursors of September Arctic sea-ice extent by adjusting the maximal lead time from one to eight months. For lead time of more than three months, June downward longwave radiation flux in the Canadian Arctic Archipelago is the only one precursor. However, for lead time of 1–3 months, August sea-ice concentration in Western Arctic represents the strongest positive correlation with September sea-ice extent, while August sea-ice concentration factors in other regions have weaker influences on the marginal seas. Other precursors include August wind anomalies in the lower latitudes accompanied with an Arctic high pressure anomaly, which induces the sea-ice loss along the Eurasian coast. These robust precursors can be used to improve the seasonal predictions of Arctic sea ice and evaluate the climate models.
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Arctic Ocean Primary Productivity: The Response of Marine Algae to Climate Warming and Sea Ice Decline
Highlights • Satellite estimates of ocean primary productivity (i.e., the rate at which marine algae transform dissolved inorganic carbon into organic material) showed higher values for 2020 (relative to the 2003-2019 mean) for seven of the nine investigated regions (with the Sea of Okhotsk and Bering Sea showing lower than average values). • All regions continue to exhibit positive trends over the 2003-2020 period, with the strongest trends in the Eurasian Arctic, Barents Sea, and Greenland Sea. • During July and August 2020, a ~600 km long region in the Laptev Sea of the Eurasian Arctic showed much higher chlorophyll-a concentrations (~2 times higher for July and ~6 times higher for August) than the same months of the multiyear average (2003-2019), associated with very early loss of sea ice in spring and summer (see essay Sea Ice).
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- PAR ID:
- 10225197
- Date Published:
- Journal Name:
- Arctic report card
- ISSN:
- 2153-5272
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.25923/vtdn-2198
