Satellite-measured seasonal and inter-annual chlorophyll variability in the Northeast Pacific and Coastal Gulf of Alaska
Satellite-measured seasonal and inter-annual chlorophyll variability in the Northeast Pacific and Coastal Gulf of Alaska
复制标题
DOI：
10.1016/j.dsr2.2003.06.003
复制
发表时间：
2004-01-01
影响因子：
3
通讯作者：
Thomas, AC
中科院分区：
文献类型：
--
作者：
Brickley, PJ;Thomas, AC
四年（1997 年 9 月至 2001 年 8 月）的 SeaWiFS 海洋颜色卫星数据用于首次对东北太平洋和阿拉斯加沿海湾的叶绿素季节性和年际时间尺度变化进行天气量化。 11 月 1 月期间的低光照水平和/或云阻碍了冬季模式的检查。气候季节模式显示，整个盆地周围的陆架叶绿素增强（3 倍或更多），沿科迪亚克岛东部边缘和南部延伸至陆架断裂处 300 m，在 5 月和 2 月达到峰值，但在 8 月至 9 月较弱。中部流域的浓度在2月份最低（<0.4 mg m(-3)），没有春季峰值，并且随季节稳步增加，到9月份达到最高浓度（接近0.7 mg m(-3)）。月图像时间序列的经验正交函数 (EOF) 分解的主导模式（总方差的 27%）显示，年际变率在盆地外围的春季高峰期间最强，并在 1998 年和 2001 年达到最小值。第二个和第三个模式（8% 和 7%）捕获了额外的春季年际变率，其模式与卡亚克岛以西的陆架断陷（西经 144 度）密切相关，并且在更分散的中尺度模式中果阿东部。三个地点的跨陆架叶绿素变异性（近海 0-400 公里）与 GOA 北部（苏厄德附近）近海的强烈季节性和春季开花发育形成鲜明对比，而夏洛特皇后群岛附近的陆架则具有较弱的季节性。威廉王子湾和科迪亚克岛之间的陆架始终形成沿陆架的叶绿素春季梯度，在陆架的西端达到最大值。与风和地表温度异常的比较表明，与1997/98年厄尔尼诺现象相关的温度异常相比，春季花期强度的年际差异与前一冬季风的强迫关系更为密切。 (C) 2004 Elsevier Ltd. 保留所有权利。
Four years (September 1997-August 2001) of SeaWiFS ocean-color satellite data are used to present the first synoptic quantification of chlorophyll variability on seasonal and interannual timescales over the Northeast Pacific and Coastal Gulf of Alaska. Low light levels and/or cloud during November January prevent examination of winter patterns. The climatological seasonal patterns show shelf-intensified chlorophyll (by a factor of 3 or more) around the entire basin, extending up to 300 m beyond the shelfbreak along the eastern margin and south of Kodiak Island, with peaks in May and again but weaker in August-September. Over the central basin, concentrations are minimum in February ( < 0.4 mg m(-3)), have no spring peak, and increase steadily over the season to a maximum (similar to0.7 mg m(-3)) in September October. The dominant mode (27% of total variance) of an empirical orthogonal function (EOF) decomposition of the monthly image time series shows interannual variability is strongest during the spring peak around the periphery of the basin with minima in 1998 and 2001. The second and third modes (8% and 7%) capture additional spring interannual variability in patterns strongly related to the shelfbreak west of Kayak Island (144degreesW) and in more diffuse mesoscale patterns in the eastern GOA. Cross-shelf chlorophyll variability (0-400 km offshore) at three locations contrasts strong seasonality and spring bloom development offshore, over the shelf break, in the northern GOA (off Seward) with weaker seasonality over the shelf off the Queen Charlotte Islands. The shelf between Prince William Sound and Kodiak Island consistently develops a spring along-shelf gradient in chlorophyll, maximum over the western end of the shelf. Comparisons to wind and surface temperature anomalies suggest that interannual differences in the strength of the spring bloom are more strongly related to wind forcing the previous winter than temperature anomalies associated with the 1997/98 El Nino. (C) 2004 Elsevier Ltd. All rights reserved.