Daily sea ice concentration product based on brightness temperature data of FY-3D MWRI in the Arctic

Figures & data

Table 1. The yearly models of bias correction at five channels. The bias between MWRI and AMSR2 TB data before and after bias correction from January 2018 to June 2020.

Channel	Slope	Intercept	Sea ice bias (K)		Open water bias (K)
			Before	After	Before	After
18.7 V	0.900	28.014	-4.0	-0.3	-9.7	<0.0
23.8 V	0.956	15.642	-5.3	-0.3	-9.5	-2.6
36.5 V	0.970	12.454	-6.0	-0.5	-10.0	-3.7
89 H	0.972	8.625	-2.5	0.1	-2.6	0.2
89 V	0.979	8.237	-3.5	<0.0	-4.2	-1.1

Figure 1. The result of daily (solid curves) and monthly (solid rectangles) dynamic sea ice tie points P₁ (orange) and open water tie points P₀ (blue) from January 2018 to June 2020.

Table 2. The information of the MWRI SIC product provided by this study.

Variable	Description
Naming convention	FY-3D_MWRI_SIC_DAILY_YYYYMMDD.tif
YYYY	Four-digit year
MM	Two-digit month
DD	Two-digit day
Projection	NSIDC Sea Ice Polar Stereographic North
Spatial resolution	12.5 km
Extent
Upper left point	30.98° N 168.35° E
Lower left point	33.92° N 80.74° W
Upper right point	31.37° N 102.34° E
Lower right point	34.35° N 9.97° W
Pixels values
0	Open water
1–100	Sea ice concentration
−1	Land
−2	Pole Hole
NoData	Missing data

Figure 2. The bias between our MWRI SIC product and AMSR2 SIC product based on the ASI algorithm using fixed tie points from January 2018 to June 2020.

Figure 3. The spatial distribution of MODIS scenes used in this study.

Table 3. The validation results of the MWRI SIC with the MODIS SIC in 2018.

No.	Date	Threshold	N	Bias (%)	RMSD (%)	R
1	02 April	0.17	225	−0.16	20.97	0.81
2	13 April	0.11	390	−0.14	8.82	0.96
3	15 April	0.13	814	−0.84	3.85	0.25
4	19 April	0.12	432	0.41	16.93	0.90
5	04 May	0.11	308	−2.17	7.29	0.91
6	12 May	0.13	598	2.07	8.50	0.70
7	25 May	0.11	315	−4.09	16.03	0.84
8	02 June	0.11	156	−2.40	12.93	0.92
9	08 June	0.16	320	−2.96	8.18	0.99
10	15 June	0.18	442	−5.22	12.00	0.96
11	26 June	0.04	437	−5.41	18.63	0.90
12	02 July	0.12	297	−4.76	12.12	0.96
13	13 July	0.14	320	−10.59	16.82	0.91
14	14 July	0.05	380	−8.38	16.42	0.91
15	22 July	0.07	390	1.83	12.34	0.95
16	02 August	0.09	192	10.76	17.35	0.94
17	06 August	0.09	378	0.93	16.59	0.81
18	13 August	0.11	456	−2.90	18.40	0.79
19	24 August	0.11	297	−4.74	11.74	0.95

Note; N is the number of compared pixels at 12.5 km resolution, “RMSD” is the root mean square deviation, “R” is correlation coefficients.

Figure 4. MODIS Band 2 reflectance, the ice-water binary map, the MODIS SIC, and the MWRI SIC of Image 1 (02 April 2018) and Image 6 (12 May 2018).

Figure 5. MODIS Band 2 reflectance, the ice-water binary map, the MODIS SIC, and the MWRI SIC of Image 3 (15 April 2018), Image 7 (25 May 2018) and Image 10 (15 June 2018).

Figure 6. MODIS Band 2 reflectance, the ice-water binary map, the MODIS SIC, and the MWRI SIC of Image 9 (08 June 2018), Image 14 (14 July 2018) and Image 16 (02 August 2018).

Figure 7. MODIS Band 2 reflectance, the ice-water binary map, the MODIS SIC, and the MWRI SIC of Image 12 (02 July 2018) and Image 19 (24 August 2018).

Table 4. The comparison results between two MWRI SICs and the corresponding MODIS SIC in 2018. “A/B”: A is the statistic results of our MWRI SIC product and B is the statistic results of the published MWRI SIC product based on the NT2 algorithm.

No.	Date	Bias (%)	RMSD (%)	R
13	13 July	−10.59/30.51	16.82/39.39	0.91/0.64
14	14 July	−8.38/0.59	16.42/21.43	0.91/0.77
15	22 July	1.83/10.83	12.34/18.83	0.95/0.93
16	02 August	10.76/19.48	17.35/30.64	0.94/0.76
17	06 August	0.93/22.10	16.59/31.97	0.81/0.63
18	13 August	−2.90/25.51	18.40/36.20	0.79/0.47
19	24 August	−4.74/26.10	11.74/35.40	0.95/0.69

Data Availability Statement

The dataset is openly available in the Science Data Bank at http://www.dx.doi.org/10.11922/sciencedb.00137.