Sea ice concentration

which refers to the percentage of sea ice in an area

is one of the important parameters describing the characteristics of sea ice. Remote sensing monitoring of Arctic sea ice is crucial for understanding the role of the Arctic in the global climate system and in global warming. Therefore

comparing and evaluating the products of sea ice data retrieved from different satellite observations are necessary. In addition

assessing the accuracy of sea ice distribution from satellite observations is significant in studies on climate change and global warming because the extrapolation of global surface energy flows is very sensitive to the estimation of Arctic sea ice cover. To evaluate sea ice concentration from the Microwave Radiometer Imager (MWRI) onboard the FY-3B satellite

we compare the data products with the sea ice concentration from the advanced microwave scanning radiometer for earth observing system (AMSR-E) onboard the Aqua satellite. High-resolution moderate resolution imaging spectroradiometer (MODIS) data are used to validate MWRI and AMSR-E sea ice concentration. The comparison of MWRI and AMSR-E incudes daily and monthly data. MODIS L1B band 2 channel reflectance is chosen to validate the sea ice concentration of MWRI and AMSR-E. The processing procedure of MODIS mainly consists of solar zenith correction

radiometric calibration

removing bow-tie phenomenon

and map projection. The map projection is the polar stereographic projection

which is the same as the MWRI and AMSR-E products. To avoid the misjudgment of ice and water because of the cloud influence

we choose cloudfree MODIS channel 2 sub-region for ice and water recognition. Different thresholds according to the histogram of the reflectance are used to segment the ice and water pixels. The MODIS sea ice concentration in each MWRI and AMSR-E grid is calculated. The comparison results of MWRI and AMSR-E are as follows. First

MWRI and AMSR-E daily mean sea ice concentrations show a consistent change from July to September

and MWRI sea ice concentration is higher than AMSR-E each day. The monthly mean values of daily biases for July

August

and September are 8.55%

7.67%

and 2.58%

and the monthly mean of daily standard deviations are 12.16%

12.08%

and 10.43%

respectively. Second

from July to September

the monthly sea ice concentration difference between MWRI and AMSR-E (MWRI minus AMSR-E) shows a decreasing trend. The monthly biases for July

August

and September are 7.37%

6.53%

and 1.51%

and the monthly standard deviations are 4.61%

4.36%

and 3.64%

respectively. The validation results of MWRI and AMSR-E sea ice concentration with MODIS are as follows. First

in the region of MODIS sea ice concentration less than 95%

the sea ice concentration difference between MWRI and MODIS (MWRI minus MODIS) is 9.78%±16.90%

and the difference between AMSR-E and MODIS (AMSR-E minus MODIS) is 0.90%±13.09%. MWRI and AMSR-E tend to overestimate sea ice concentration compared with MODIS

the result of AMSR-E is closer to MODIS

and MWRI has a larger error. Second

when MODIS sea ice concentration is greater than or equal to 95%

the sea ice concentration difference between MWRI and MODIS is –5.45%±7.05%

and the difference between AMSR-E and MODIS is –7.97%±6.46%. MWRI and AMSR-E tend to underestimate sea ice concentration compared with MODIS

and the result of MWRI is slightly better.