Simulated Geophysical Noise in Sea Ice Concentration Estimates of Open Water and Snow-covered Sea Ice

Sea ice concentration algorithms using brightness temperatures ( T B ) from satellite microwave radiometers are used to compute sea ice concentration ( c ice ), sea ice extent, and generate sea ice climate data records. Therefore, it is important to minimize the sensitivity of c ice estimates to geo...

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Bibliographic Details
Published in:IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
Main Authors: Tonboe, Rasmus, Nandan, Vishnu, Makynen, Marko P., Pedersen, Leif Toudal, Kern, Stefan, Lavergne, Thomas, elund, Johanne, Dybkjar, Gorm, Saldo, Roberto, Huntemann, Marcus
Format: Article in Journal/Newspaper
Language:English
Published: 2022
Subjects:
Microwave radiometry
Sea ice concentration
Sea ice emission modelling
/dk/atira/pure/sustainabledevelopmentgoals/climate_action
name=SDG 13 - Climate Action
Antarc*
Antarctic
Sea ice
Online Access:https://orbit.dtu.dk/en/publications/aeedef32-efd3-4052-b2b1-5043c5006c8b
https://doi.org/10.1109/JSTARS.2021.3134021
https://backend.orbit.dtu.dk/ws/files/270340565/Simulated_Geophysical_Noise_in_Sea_Ice_Concentration_Estimates_of_Open_Water_and_Snow_Covered_Sea_Ice.pdf
Description
Summary:Sea ice concentration algorithms using brightness temperatures ( T B ) from satellite microwave radiometers are used to compute sea ice concentration ( c ice ), sea ice extent, and generate sea ice climate data records. Therefore, it is important to minimize the sensitivity of c ice estimates to geophysical noise caused by snow/sea ice thermal microwave emission signature variations, and presence of WV and clouds in the atmosphere and/or near-surface winds. In this study, we investigate the effect of geophysical noise leading to systematic c ice biases and affecting c ice standard deviations (STD) using simulated top of the atmosphere T B s over open water and 100% sea ice. We consider three case studies for the Arctic and the Antarctic and eight different c ice algorithms, representing different families of algorithms based on the selection of channels and methodologies. Our simulations show that, over open water and low c ice , algorithms using gradients between V-polarized 19-GHz and 37-GHz T B s show the lowest sensitivity to the geophysical noise, while the algorithms exclusively using near-90-GHz channels have by far the highest sensitivity. Over sea ice, the atmosphere plays a much smaller role than over open water, and the c ice STD for all algorithms is smaller than over open water. The hybrid and low-frequency (6 GHz) algorithms have the lowest sensitivity to noise over sea ice, while the polarization type of algorithms has the highest noise levels.

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