Improving L-band radiation model and representation of small-scale variability to simulate brightness temperature of sea ice

ABSTRACT

The L-band microwave has the ability for penetrating snow and sea ice, hence the potential for data retrieval of snow depth and sea ice thickness. The L-band radiometer Soil Moisture and Ocean Salinity has been applied to retrieve sea ice parameters using a L-band radiation model. Here, we improve the L-band radiation model in two ways. First, instead of a single layer, we reformulate the model to consider multiple layers for sea ice and snow to better characterize the radiative effect of vertical temperature and salinity profile within the sea ice and the snow cover. Second, we incorporate small-scale sea ice variability, sea ice leads, which are not distinguishable with the L-band satellite data but have profound impacts on the simulated brightness temperature. Small-scale features of the sea ice cover such as leads can significantly lower the overall brightness temperature (). The results show that the improved radiation model can correct sea ice type dependent biases of (R² from 0.05 to 0.72) and compensate for the overestimation of when (refrozen) leads are ignored (R² from 0.51 to 0.62). The improved radiation model could serve as the basis of the retrieval of sea ice thickness or snow depth.

Acknowledgements

The authors would like to thank the editors and potential reviewers in their effort to help improve the manuscript. This work is partially support by National Key R&D Program of China: [Grant Number 2017YFA0603902] and the National Science Foundation of China: [Grant Number 41575076].

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the National Natural Science Foundation of China: [Grant Number 41575076] and National Key R&D Program of China: [Grant Number 2017YFA0603902].