| The data in Bering Sea of 2007 spring is used to analyze main factors to cause the high-frequency variation of the irradiance. Three kinds of factors influence mainly on the irradiance and the effects they produced are distinguishable from data itself. It thus is possible for us to judge and calculate the impact from different factors without detailed in situ information. The variations of irradiance by the cloud are usually with lower frequency and higher amplitude. Those caused by fog expresses complex variation with higher amplitude and with periods from several to a hundred seconds. The complexity is useful to distinguish fog from cloud. Under the clear sky condition, the steady incident solar radiation is reflected on the sea surface, modulated by the wave oscillation, and then scattered from the particles in air to the collector of the instrument. So the sea wave signal appears in the irradiance record with short period and low amplitude, clearly different from the cloud and fog. In this study, the influence of cloud, fog, and wave on irradiance is analyzed and calculated, which is valuable for understanding the irradiance and the corresponding variation in the underwater record.The ocean optical data obtained from Joint Ocean Ice Study (JOIS) 2006 in Canada Basin of 2006 summer is used to calculate the diffuse attenuation coefficient of downwelling irradiation(kd) . According to the vertical distribution of kd, the diffuse attenuation coefficient of the Canada Basin is divided into three types, namely, high-attenuation type off coastal, central high-attenuation type and vertical uniform type. Euphotic Depth and optical thickness are calculated to analyze the horizontal distribution of kd. Canada Basin is divided into three areas in terms of different horizontal distribution of attenuation characteristics. The minimum euphotic depth is observed in off-shore waters near Barrow. The maximum euphotic depth occurs in deep water, which the west caused by Pacific waters of advection and diffusion is smaller than the eastern part because of the impacts of the phytoplankton of the Pacific waters. The west ocean is very clear because of non-arrival of the Summer Pacific Water to bring about the maximum euphotic depth, which reveals the summer pacific water extend northward along the west side of the Canada Basin in depth of 30-60m range.The algorithm is given by Morel to meet the Canada Basin. The exponential relationship between the chlorophyll concentration and diffuse attenuation coefficient in 412,443,465,490,510,532,555 and 565nm are got. The correlation coefficient of 443nm is a maximum value, 0.85. the longer wavelength is consistent with the smaller correlation coefficient. When the wavelength is greater than 600nm, the relationship between the chlorophyll concentration and diffuse attenuation does not meet the exponential relationship. Compared with the lower latitude ocean, the fitting coefficients are difference. ? cis the same, but e is a half in Canada Basin, which show that the extinction capability of chlorophyll in Canada Basin is smaller to cause the smaller diffuse attenuation coefficient.To illustrate the impact of the marine phytoplankton on ocean heat absorption, the process of insulated heating is established to apply to the Canada Basin. The use of attenuation coefficient from marine optical data and insulated heating to simulate the adiabatic heating water from uniform convection of the upper mixed layer in winter to subsurface structure in summer. In whole process, the final temperature obtained by the optical model is good agreement with the observation data of subsurface structure. It is confirmed in Canada Basin that the insulated heating to sea water is a mainly reason to form the subsurface formation.The absorption of solar radiation by sea water is divided into sea water molecules and other substances in seawater, mainly phytoplankton. On-site observations of the diffuse attenuation coefficient and beam attenuation coefficient of pure water derived from lab were used to calculate solar radiation absorption by water molecules and solar radiation absorption by other substances. The differ between each other have a greater attenuation in the 10-50m range, which is suggesting that the main useful of phytoplankton impact on the absorption of this water. 018 station needs 50d to form the subsurface water. And the pure water is calculated through insulated heating process, which need 72d. It is indicating that the absorption of phytoplankton can result in accelerating to form subsurface water.Since last summer, a strong mixed layer is observed. The heat absorbed by upper mixed layer used to melt ice or transported to the atmosphere. In the ice region, the mainly use is to melt sea ice. The results show that during the period occurred in the subsurface, due to the presence of phytoplankton, water absorbs the heat by 22%, which significantly improves the rate of melting ice.The insulated heating process reflects the maximum possible absorption of solar radiation of sea water and phytoplankton. It plays an important role on the temperature structure of Arctic Ocean water. It reflects a structural change in temperature by phytoplankton in Arctic rapid changes, also increased positive feedback effect of melting sea ice. |
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