Physical Oceanography of Aniva Bay (Sea of Okhotsk)
摘要
In light of the global imperative for carbon neutrality, a through evaluation of ocean-related greenhouse gas emission sources is cruical. A system of coastal marine carbon testing sites, termed carbon polygons, has been implemented across Russia, with Aniva Bay hosting one such site. A meticulous analysis of prior works focused on the hydrology of Aniva Bay is provided, along with significant new insights stemming from our independent research. The findings from the analysis of temperature, salinity, currents, tides, wind waves, and ice conditions are presented herein. The yearly cycle observed in water temperature is characterized by peak values at depths of 0–30 m during late August and early September, and at 100 m depth in December. The interannual variability of monthly mean water temperature is most pronounced in July and August, with an increase of about 1 °C over the past 40 years. Maximum water temperatures are observed in August, reaching 20.1 °C. The spatial mean salinity at the depths of 75–100 m is ~ 33.0 while at the sea surface it is ~ 31.8. Currents near the sea surface exhibit seasonal variability that aligns with the monsoonal characteristics of atmospheric circulation. In spring and autumn, a cyclonic eddy is detected in the central part of the bay, whereas an anticyclonic eddy dominates in summer. The speed of currents in Aniva Bay changes from 5 to 10 cm/s in spring to 20–25 cm/s in winter. The range of tidal level fluctuations reaches 1.4 m during spring tides and about 0.4 m during neap tides. According to observations, the seiche periods are 4.7, 2.0, 1.0, 0.5, and 0.3 h, while model simulations provide periods of 3.2, 1.81, 1.52, 1.33, and 1.05 h. Ice formation in the bay is frequently recorded during the period from January 15 to February 10. On average, ice coverage stands at 20%, and an analysis of interannual variability from 1991 to 2020 indicates a trend of increasing ice coverage by 4%.