(Table 2) Comparison of surface chlorophyll a concentrations determined by satellite and expedition data in the Southern Ocean and the East Antarctic seas in February-April 2000

In February and April 2000, in the Southern Ocean between Africa and Antarctica, concentration of chlorophyll (Cchs) in the surface layer was not high (0.1-0.3 mg/m**3). Zones of increased Cchs values (0.6-2.0 and over 2.0 mg/m**3) were located between the Southern Subtropical and Subantarctic fronts, near the Polar front, and to the south of the Antarctic Divergence. From February to April, in open areas of the Southern Ocean, a general Cchs decrease was observed. A similar trend was also noted in near-shore seas of the East Antarctic. At the shelf of the Sea of Cosmonauts, within the upper mixed layer, the content of chlorophyll amounted to 0.34-0.37 mg/m**3 . In the area of the continental slope, we registered formation of a subsurface chlorophyll maximum (0.52-0.56 mg/m**3) at 20 m depth, which deepened to 70 m when passing to the deepwater area. The positive correlation with a high coefficient (r = 0.939) between the field and satellite data (Cchs and Csat, respectively) allows one to conclude about applicability of the SeaWiFS algorithm for estimation of chlorophyll content within the surface layer in the Antarctic areas studied. In the course of ice formation in Prydz Bay, during five days, content of chlorophyll in different phases of new ice increased by a factor of 2.9, whereas values of this parameter in the surrounding waters remained quite invariable. The Csat values were 6.3 times as high as those obtained experimentally for sludge ice. Because of large areas occupied by floating ice, the sole usage of satellite data may cause great errors in productivity estimation of for the East Antarctic seas.

2000年2月与4月期间，在非洲与南极洲之间的南大洋（Southern Ocean）表层水体中，叶绿素浓度（Cchs）处于较低水平（0.1~0.3 mg/m³）。叶绿素浓度（Cchs）升高的区域（浓度范围0.6~2.0 mg/m³及＞2.0 mg/m³）分布于南亚热带锋与亚南极锋之间、极锋（Polar front）附近，以及南极辐散带（Antarctic Divergence）南侧。2月至4月期间，南大洋开阔海域的Cchs整体呈下降趋势，东南极近岸海域也观测到了类似的变化趋势。在宇航员海（Sea of Cosmonauts）陆架区的上层混合层（upper mixed layer）内，叶绿素含量为0.34~0.37 mg/m³；在大陆坡区域，研究人员于20米水深处观测到次表层叶绿素最大值层（subsurface chlorophyll maximum）形成，其浓度介于0.52~0.56 mg/m³，当向深水区过渡时，该最大值层的深度加深至70米。现场观测数据（对应Cchs）与卫星数据（对应Csat）之间存在显著正相关，相关系数r=0.939，由此可推断SeaWiFS算法适用于本次研究的南极海域表层水体叶绿素含量的估算。在普里兹湾（Prydz Bay）的海冰形成过程中，为期5天的观测显示，新生海冰不同发育阶段的叶绿素含量提升了2.9倍，而周边海域的该参数值基本保持稳定。卫星反演得到的Csat值是泥冰（sludge ice）实验实测值的6.3倍。由于浮冰覆盖范围广阔，仅使用卫星数据估算东南极海域的海洋生产力，可能会产生较大误差。