Airborne Observations of Summer Thinning of Multiyear Sea Ice Originating From the Lincoln Sea

Autor: Christian Haas, Justin Beckers, J Alec Casey, Benjamin Lange
Rok vydání: 2018
Předmět:
010504 meteorology & atmospheric sciences
Oceanography
Atmospheric sciences
01 natural sciences
Remote Sensing
Marine Electromagnetics
sea ice mass balance
Geochemistry and Petrology
Ice Mechanics and Air/Sea/Ice Exchange Processes
Arctic Ocean
Earth and Planetary Sciences (miscellaneous)
Sea ice
Melt pond
sea ice thickness
The Arctic: An AGU Joint Special Collection
14. Life underwater
Instruments and Techniques
Geodesy and Gravity
Research Articles
0105 earth and related environmental sciences
geography
geography.geographical_feature_category
Buoy
Ocean/Earth/atmosphere/hydrosphere/cryosphere interactions
Sea Ice
electromagnetic induction
Marine Geology and Geophysics
Snow
Arctic ice pack
Depth sounding
Geophysics
Mass Balance
13. Climate action
Space and Planetary Science
Snowmelt
Sea ice thickness
satellite image
Cryosphere
Geology
Oceanography: Physical
Research Article
Zdroj: Journal of Geophysical Research. Oceans
ISSN: 2169-9275
Popis: To better understand recent changes of Arctic sea ice thickness and extent, it is important to distinguish between the contributions of winter growth and summer melt to the sea ice mass balance. In this study we present a Lagrangian approach to quantify summer sea ice melt in which multiyear ice (MYI) floes that were surveyed by airborne electromagnetic thickness sounding within Nares Strait during summer were backtracked, using satellite imagery, to a region in close proximity (3–20 km) to spring ice thickness surveys carried out in the Lincoln Sea. Typical modal total MYI thicknesses, including ~0.4‐m snow, ranged between 3.9 and 4.7 m in the Lincoln Sea during April. Ice‐only modal thicknesses were between 2.2 and 3.0 m in Nares Strait during August. Total thinning including snow and ice was 1.3 ± 0.1 m including 0.4 ± 0.09 m of snow melt and 0.9 ± 0.2 m of ice melt. This translates to a seasonal net heat input of 305 ± 69 MJ/m2 (262 ± 60 MJ/m2 for ice only) and seasonal net heat flux of 57 ± 13 W/m2 (45 ± 10 W/m2 for ice only), which is unlikely to be explained by solar radiation fluxes alone. Furthermore, our approach provides an improvement on traditional ice mass balance buoy estimates because it integrates melt over larger spatial scales, where melt can be highly variable due to differential melt experienced between melt ponds, bare ice, hummocks, and ridges.
Key Points MYI surveyed in the Lincoln Sea during spring had modal thicknesses of 3.9‐4.7 m, which thinned to 2.2‐3.0 m in summer in Nares StraitBacktracking individual floes with satellite images was used to reconstruct positions of the same ice fields surveyed in spring and summerEstimated sea ice melt was 0.9 +/‐ 0.2 m, slightly higher than observations by ice mass balance buoys for the same region
Databáze: OpenAIRE
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