Variability in the western equatorial Pacific Ocean during Japanese Pacific climate study cruises in 1989 and 1990
Variability in the western equatorial Pacific Ocean during Japanese Pacific climate study cruises in 1989 and 1990
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1989年和1990年日本太平洋气候研究航行期间赤道西太平洋的变化
DOI：
10.1029/92jc02684
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发表时间：
1993
影响因子：
--
通讯作者：
M. Mcphaden
中科院分区：
文献类型：
--
作者：
Y. Kuroda;M. Mcphaden
数据来自 1989 年 1 月至 2 月和 1990 年 1 月至 2 月期间 Natsushima 号在北纬 5°至南 5°、东经 160°至西 160°地区的两次航行。这些航行是在南方涛动指数极端期间在赤道中太平洋冷舌和西赤道太平洋暖池的气候敏感区域进行的。 （SOI）。与 1989 年 1 月至 2 月的高 SOI 值相关，在东经 160 度至西经 160 度之间的赤道盛行异常强的信风。在南赤道流中，表层的水流以高达 60-80 cm s[sup [minus]1] 的速度向西流动，上层 100 m (300 m) 的体积输送量为 52 Sv (98 Sv)，穿过北纬 5° 和南纬 5° 之间的日期变更线向西流动。一年后，当 SOI 处于负极端时，流量和水文条件明显不同。日界线以西风速达到10 m s[sup [minus]1]，上温跃层纬向坡度和地表动态高度发生逆转，西经160°到东经160°之间地表层升温2°-3°C，冷舌从西太平洋消失。纬向流在东经 155° 至 175°E 之间沿赤道上部 75 m 反向流动，以 20-60 cmmore » s[sup [minus]1] 的速度向东流动。相反，180°以东，盛行东风面风和西面面流，因此日界线附近面纬向风和海流都汇聚。与这种收敛相关，表面动态高度上升了 12 达因厘米，并且在表面层中形成了相对尖锐的水团特性的纬向梯度。对两次航行的深度综合纬向动量平衡的诊断表明，上层海洋输送的变化不能解释为对当地风力强迫的线性平衡响应。 28 条参考文献，11 个图，2 个标签。« 更少
Data are examined from two cruises of the R/V Natsushima in the region 5[degree]N to 5[degree]S, 160[degree]E to 160[degree]W during January-February 1989 and January-February 1990. These cruises were conducted in the climatically sensitive region of the central equatorial Pacific cold tongue and the western equatorial Pacific warm pool during extremes of the Southern Oscillation index (SOI). Associated with high SOI values in January-February 1989, anomalously strong trade winds prevailed along the equator between 160[degree]E and 160[degree]W. Flow in the surface layer was to the west at speeds up to 60-80 cm s[sup [minus]1] in the South Equatorial Current, and volume transport in the upper 100 m (300 m) was 52 Sv (98 Sv) to the west across the date line between 5[degree]N and 5[degree]S. Flow and hydrographic conditions were markedly different 1 year later when the SOI was at a negative extreme. Winds became westerly west of the dateline at speeds up to 10 m s[sup [minus]1], the zonal slope of the upper thermocline and of surface dynamic height reversed, the surface layer warmed by 2[degree]-3[degree]C between 160[degree]W and 160[degree]E, and the cold tongue disappeared from the western Pacific. Zonal currents reversed and flowed eastward at speeds of 20-60 cmmore » s[sup [minus]1] in the upper 75 m along the equator between 155[degree]E and 175[degree]E. Conversely, east of 180[degree] easterly surface winds and westeard surface flow prevailed, so that near the date line both surface zonal winds and currents were convergent. Associated with this convergence, surface dynamic height rose by 12 dyn cm, and a relatively sharp zonal gradient in water mass properties developed in the surface layer. Diagnosis of the depth integrated zonal momentum balance for both cruises indicated that the changes in upper ocean transport could not be interpreted as a linear equilibrium response to local wind forcing. 28 refs., 11 figs., 2 tabs.« less