Analysis of sea ice conditions and navigability in the Arctic Northeast Passage during the summer from 2002-2021

Figures & data

Figure 1. The primary seas and straits through the NEP and the Eastern Arctic region. The red sector represents the study area and the red curve shows the NEP.

Table 1. Information of the passive microwave remote-sensing data.

Data source	Time period	Band (GHz)	Spatial resolution (km)
AMSR-E	July 1, 2002– October 4, 2011	36	12.50
		89	6.25
SSMIS	July 1, 2010– October 31, 2014	37	25.00
		91	12.50
AMSR2	July 2, 2012– October 31, 2021	36	12.50
		89	6.25

Table 2. Linear regression coefficients for AMSR-E and SSMIS brightness temperature data.

Band	Month	Slope	Intercept	R^2
36V	07	0.955	9.427	0.896
	08	0.985	2.492	0.803
	09	1.004	−2.286	0.794
	10	0.980	3.136	0.934
36H	07	0.925	17.113	0.911
	08	0.924	16.457	0.848
	09	0.908	18.037	0.849
	10	0.928	15.487	0.943
89V	07	0.431	144.748	0.657
	08	1.319	−78.798	0.762
	09	1.526	−130.101	0.869
	10	0.957	9.763	0.898
89H	07	0.654	81.833	0.774
	08	0.911	21.571	0.745
	09	0.937	14.200	0.770
	10	0.920	17.676	0.878

Figure 2. Comparison of daily average brightness temperature before and after inter-calibration for AMSR-E and SSMIS.

Table 3. Linear regression coefficients for AMSR2 and SSMIS brightness temperature data.

Band	Month	Slope	Intercept	R^2
36V	07	0.902	20.839	0.869
	08	0.882	23.932	0.773
	09	0.829	34.040	0.778
	10	1.030	−9.996	0.943
36H	07	0.928	14.254	0.896
	08	0.914	15.612	0.828
	09	0.896	17.107	0.843
	10	0.939	10.776	0.948
89V	07	0.639	91.792	0.700
	08	0.750	60.767	0.826
	09	1.468	−115.727	0.911
	10	0.939	12.404	0.924
89H	07	0.685	74.389	0.743
	08	0.934	15.434	0.702
	09	0.955	9.084	0.686
	10	0.889	22.542	0.886

Figure 3. Comparison of daily average brightness temperature before and after calibration for AMSR2 and SSMIS.

Figure 4. Variation of daily SIE from July to October of 2002–2006.

Figure 5. Maximum and minimum SIC during 2002–2021.

Figure 6. Variation of Monthly average SIE from July to October of 2002–2021.

Figure 7. Monthly average SIE in September of 2002–2021.

Figure 8. Variation of multi-year average SIE per ten days from July to October of 2002–2021.

Figure 9. Multi-Year average SIC per ten days from July to October of 2002–2021.

Figure 10. Variation of daily average thin SIT from July to October of 2002–2021.

Figure 11. Spatial distribution of the maximum and minimum SIT.

Figure 12. Spatial distribution of multi-year average SIT per ten days from July to October of 2002–2021.

Figure 13. Navigation period of the NEP in summer seasons of 2002–2021.

Figure 14. Navigation routes for the NEP in 2012, 2013, and 2015.

Figure 15. Navigation period and ship routes in 2012, 2013, and 2015. (a) Navigation period and R/V XueLong route in 2012; (b) Navigation period and M/V YongSheng route in 2013; (c) Navigation period and M/V YongSheng route in 2015.

Data availability statement

The AMSR-E and SSMIS dataset that support the findings of this study is openly available in https://nsidc.org/data/AE_SI12 and https://nsidc.org/data/NSIDC-0001 by the NSIDC, and the AMSR2 dataset that support the findings of this study is openly available in https://seaice.uni-bremen.de/data/amsr2 by the Bremen University. The ship-based SIC dataset that support the findings of this study is available from the corresponding author, upon reasonable request.