Comparative analysis of satellite and shipborne data on ice cover in the Russian Arctic seas

Abstract

The SSM/I data processed by the NASA Team algorithm are used to compare the total ice concentration obtained from the visual shipborne observations with satellite images. A comparison of the satellite images with the shipborne data shows significant differences with the shipborne data observed onboard ice-breakers during 15 scientific expeditions to the Barents, Kara, Laptev, and East Siberian seas. The most pronounced differences are observed in the ice edge regions. They cause errors in the estimates of the total ice concentration and ice extent, which makes difficult to use them in various practical and scientific tasks. Generally, the methods of remote sensing (RS) underestimate the real sea ice concentration: the average error is on the order of 10% in both winter and in summer. A statistical analysis of the comparison of two sources of information was carried out separately for the total ice concentration for summer and winter data taking into account the new ice and without it. During the summer period in the area of open ice, the SSM/I data over-estimate the total ice concentration by 0.5–1, but in close ice they underestimate it on average by 2 grades. If the new ice is subtracted from the total ice concentration obtained onboard the icebreakers, the total error decreases to −3.4%. In the winter period in the region of rare ice, the SSM/I data overestimate the total ice concentration by 1–2 grades, but in close ice this difference is as high as 2, like in summer. New ice in winter is determined better by remote sensing methods than in summer; hence, its exclusion from the total ice concentration does not lead to a decrease in the average error.