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Photosynthetically Available Radiation (PAR) is an important bio-op-tical parameter related to marine primary production. PAR is usually measured by a broadband sensor and can also be calculated by multispectral data. When the PAR is calculated by multispectral data in polar region, four factors are possible error sources. PAR could be overestimated as the wavelengths of multispectral instrument are usually chosen to evade main absorption zones of atmosphere. However, both PARs calculated by hyperspectral and multispectral data are consistent with an error less than 1%. By the fitting function proposed here, the PAR calculated by multispectral data could attain the same accuracy with that by hyperspectral data. To calculate the attenuation rate of the PAR needs PAR0, the PAR just under the surface. Here, an approach is proposed to calculate PAR0 by the best fit of the irradiance profile of 1-5 m with a content attenuation coefficient under surface. It is demonstrated by theory and observed data in different time at same location that the attenuation coefficient of PAR is independent of the intensity of radiation. But under sea ice, the attenuation coefficient of PAR is a little bit different, as the spectrum of the light has been changed by selective absorption by the sea ice. Therefore, the difference of inclusions inside the sea ice will result in different PAR, and impact on the attenuation of PAR. By the results of this paper, PAR can be calculated reliably by multispectral data.
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The distribution and abundance of euphausiid larvae and salps was studied from samples collected in 2002 and 2006 from Prydz Bay, Antarctica. Larvae of
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A case of a snowstorm at the Great Wall Station was studied using data of NCEP (National Centers for Environmental Prediction) analysis, in situ observations and surface weather charts. The storm occurred on August 29th, 2006, and brought high winds and poor horizontal visibility to the region. It was found that the storm occurred under the synoptic situation of a high in the south and a low in the north. A low-level easterly jet from the Antarctic continent significantly decreased the air temperature and humidity. Warm air advection at high levll brought sufficient vapor from lower latitudes for the snowstorm to develop. The dynamic factors relating to strong snowfall and even the development of a snowstorm were deep cyclonic vorticity at middle and low levels, the configuration of divergence at high level and convergence at low level, and strong vertical uplift. There was an inversion layer in the low-levll atmosphere during the later phase of the storm. This vertical structure of cold air at low levels and warm air at high levels may have been important to the longevity of the snowstorm.
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The glaciers Austre Lovénbreen and Pedersenbreen are located at Ny-Ålesund, Svalbard. The surface mass balance and ice flow velocity of both glaciers have been determined from the first year of observations (2005/2006), while the front edge of Austre Lovénbreen was also surveyed. The results are as follows: (1) The net mass balances of Austre Lovénbreen and Pedersenbreen are — 0.44 and —0.20 m w.e., the annual ablation is —0.99 and —0.94 m w.e., and the corresponding equilibrium line altitudes are 478.10 and 494.87 m, respectively. (2) Austre Lovénbreen and Pedersenbreen are characterized as ice flow models of surge-type glaciers in Svalbard. The horizontal vectors of the ice flow velocities are parallel or converge to the central lines of both glaciers, with lower velocities in the lower ablation areas and higher velocities in the middle and upper reaches of the glaciers. The vertical vectors of ice flow velocities show that there is a mass loss in the ablation areas, which reduces with increasing altitude, while there is a mass gain near the equilibrium line of Austre Lovénbreen. (3) The front edge of Austre Lovénbreen receded at an average rate of 21.83 m · a-1, with remarkable variability-a maximum rate of 77.30 m · a-1 and a minimum rate of 2.76 m · a-1.
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Based on the observed and NCEP reanalysis data from 1985 to 2006, the climate background and synoptic situation of fog at Great Wall Station were analyzed. It is shown that the seasonal variation of fog is controlled by the change of general circulation and local pressure field. Three favorable typical synoptic situations for fog development are found, the Front-of-A-Depression type, the Saddle-Shaped-Field type and the Passing-Weak-Cyclone type. The first one is the most important situation. Advection cooling fog is dominant at Great Wall Station, but there are other kinds of fog as well. As a result, some helpful principles for local fog forecasting are given.
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Standard FISH protocols using fluorochrome-labeled oligonucleotide probes have been successfully applied for
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A regional sea ice-ocean coupled model for the Arctic Ocean was developed, based on the MITgcm ocean circulation model and classical Hibler79 type two category thermodynamics-dynamics sea ice model. The sea ice dynamics and thermodynamics were considered based on Viscous-Plastic (VP) and Winton three-layer models, respectively. A detailed configuration of coupled model has been introduced. Special attention has been paid to the model grid setup, subgrid paramerization, ice-ocean coupling and open boundary treatment. The coupled model was then applied and two test run examples were presented. The first model run was a climatology simulation with 10 years (1992—2002) averaged NCAR/NCEP reanalysis data as atmospheric forcing. The second modll run was a seasonal simulation for the period of 1992—2007. The atmospheric forcing was daily NCAR/NCEP reanalysis. The climatology simulation captured the general pattern of the sea ice thickness distribution of the Arctic，i.e., the thickest sea ice is situated around the Canada Archipelago and the north coast of the Greenland. For the second model run, the modeled September Sea ice extent anomaly from 1992—2007 was highly correlated with the observations, with a linear correlation coefficient of 0.88. The minimum of the Arctic sea ice area in the September of 2007 was unprecedented. The modeled sea ice area and extent for this minimum was overestimated relative to the observations. However, it captured the general pattern of the sea ice retreat.
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In order to study the adaptability of Arctic microalgae to different environmental temperatures, the growth curves and antioxidase system of three microalgae (
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During the 2006/07 Antarctic summer, the species population, distribution and reproductive behavior of penguins in areas near the Great Wall Station were investigated. Five species of penguin were recorded: gentoo penguin (
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