**Abstract**

The chapter is divided into 5 parts. The first part describes what the satellite data is and describes the levels of its processing. In the second part, attention is paid to sea surface temperature anomalies, the conditions for the appearance of the most significant anomalies and their influence on the behavior and survival of aquatic organisms are described. The third part is devoted to calculating linear trends in ocean surface temperature from a 20-year series of satellite data. It is shown that the heat content of the surface layer of Okhotsk Sea decreases, most significantly in its northern and western parts. This trend is especially pronounced in the spring, which may be due to a decrease in ice cover and a more significant cooling of the waters due to winter convection. In the fourth part, periodic fluctuations in the temperature of the surface of the ocean are considered. It is demonstrated how, using the calculated trend and several basic harmonics, one can try to predict the temperature next year. And the last part concludes the chapter.

**Keywords:** satellite data, sea surface temperature, Tsushima current, Okhotsk Sea, regional effects of global warming, SST anomalies, trends, harmonic, cyclicity

## **1. Introduction**

The study of the thermal regime of various water areas is one of the most important oceanological problems, since the spatio-temporal variability of water temperature reflects complex processes of formation, transformation and dynamics of water masses. In addition, temperature is one of the key parameters that determine the conditions for the existence and development of most species of aquatic organisms; therefore, the study of this problem is also of key importance for hydrobiology. The zoning of water areas by the nature of temperature conditions, as well as their forecasting, taking into account the peculiarities of seasonal and interannual variability, is an important scientific task, which also has a pronounced applied aspect associated with the fact that accumulations of some species of commercial fish are confined to the zones of separation of water masses with different characteristics.

Direct measurements are a traditional source of water temperature data. Their accuracy depends only on the accuracy of the device, and the discreteness depends on the specific task (in some cases it can reach a fraction of a second). They can also be used to construct vertical profiles with high vertical resolution. However, recently the number of expeditions has been steadily declining, and the data obtained through direct measurements are point and irregular and are not suitable for studying large-scale phenomena or for obtaining data from hard-to-reach places.

Satellite data, on the other hand, are regular and allow covering the entire water area of the studied basin. Therefore, they are very good sources for studying seasonal and interannual variations in the temperature of the surface layer (the thickness of which ranges from 1 to 10 meters). The disadvantage of these data is the strong dependence of accuracy on cloudiness (especially in the infrared and visible ranges). Ideally, they should be regularly compared with direct measurements in order to identify errors in data interpretation.

For scientific purposes, data are usually used from satellites located either in a geosynchronous (in a particular case, geostationary orbit) or in a heliosynchronous orbit. The advantage of the geostationary orbit is obvious: you can get a picture of the same area with discreteness of up to half an hour, and after pointing to the satellite, a constant correction of the antenna position is not required. It is very useful for telecommunication systems as well as for obtaining meteorological data. The disadvantage is the lack of coverage at polar latitudes.

This disadvantage is easily eliminated by satellites in a polar sun-synchronous orbit. A sun-synchronous orbit is important to science because it keeps the angle of incidence of sunlight on the Earth's surface more or less constant, although the angle will change with the change of seasons. Without a sun-synchronous orbit, you would have to account for changes in shadow and lighting angles, making it difficult to track changes over time. It would simply be impossible to collect the information needed to study climate change.

In 1997, a TeraScan satellite receiving station was installed at SakhNIRO, with the help of which data are received from the NOAA, Metop, Aqua and Terra satellites in a polar sun-synchronous orbit (**Figure 1** [1]). At the moment, a 21-year series of satellite data on the temperature of the surface of the Sea of Okhotsk and adjacent waters has been accumulated, which makes it possible to analyze the interannual variations of this parameter.

**Figure 1.**

*Example of a sun-synchronous orbit for a NOAA satellite [1].*

*Analysis of Spatiotemporal Variability of Surface Temperature of Okhotsk Sea and Adjacent… DOI: http://dx.doi.org/10.5772/intechopen.94918*

This chapter is organized as follows:

