Mixed-layer water oscillations in tropical Pacific for ENSO cycle
Mixed-layer water oscillations in tropical Pacific for ENSO cycle
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ENSO循环中热带太平洋混合层水振荡
DOI：
10.1007/s11430-007-0098-5
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发表时间：
2007-12
期刊：
影响因子：
--
通讯作者：
Wang Fan
中科院分区：
文献类型：
--
作者：
Zhao Yongping;Wu Aiming;Chen Yongli;Wang Fan
本文研究了热带太平洋温跃层和海面风应力年际变化的主要模态及其相互作用。(1)热带太平洋温跃层异常具有以160°W为轴的纬向偶极子型和以6-8°N为横轴的纬向跷跷板型。纬向振荡与纬向振荡相差约90°，两者结合形成厄尔尼诺/拉尼娜循环，表现为赤道至12°N之间的热带太平洋海盆内混合层水的逆振荡。(2)热带太平洋风应力异常主要有两种类型，第一种是信风异常引起的赤道太平洋纬向风应力异常及其对应的辐散场，第二种是越赤道气流风应力异常及其对应的辐散场，其符号与赤道地区相反。第二个分量代表热带北太平洋离赤道地区的风应力异常及其相应的辐散。(3)信风异常对ENSO循环的强度和相变起着决定性的作用，它导致海平面倾斜，为混合层水振荡提供初始势能，并引起赤道东西两侧以及赤道与北太平洋海盆12°N之间的逆温跃层位移。从而决定了ENSO循环的振幅和路径。ITCZ异常对相变有一定的影响。(4)热带西太平洋的热力异常引起风应力异常，并伴随着赤道太平洋混合层水振荡沿赤道沿着东延伸，引起信风异常，产生有利于振荡的异常风应力和相应的辐散，使振荡加剧。海气相互作用的耦合系统和混合层水振荡的惯性重力共同提供了ENSO循环的位相转换机制和年际记忆。因此，ENSO循环实质上是信风异常和海气耦合作用共同作用下赤道到12°N之间热带太平洋海盆混合层水的惯性振荡。当海气耦合作用产生的力大于或等于混合层水振荡所产生的阻力时，混合层水振荡将较强或维持不变;当海气耦合作用产生的力小于混合层水振荡所产生的阻力时，混合层水振荡将较弱甚至破裂。
The main modes of interannal variabilities of thermocline and sea surface wind stress in the tropical Pacific and their interactions are investigated, which show the following results. (1) The thermocline anomalies in the tropical Pacific have a zonal dipole pattern with 160°W as its axis and a meridional seesaw pattern with 6–8°N as its transverse axis. The meridional oscillation has a phase lag of about 90° to the zonal oscillation, both oscillations get together to form the EI Niño/La Niña cycle, which behaves as a mixed layer water oscillates anticlockwise within the tropical Pacific basin between equator and 12°N. (2) There are two main patterns of wind stress anomalies in the tropical Pacific, of which the first component caused by trade wind anomaly is characterized by the zonal wind stress anomalies and its corresponding divergences field in the equatorial Pacific, and the abnormal cross-equatorial flow wind stress and its corresponding divergence field, which has a sign opposite to that of the equatorial region, in the off-equator of the tropical North Pacific, and the second component represents the wind stress anomalies and corresponding divergences caused by the ITCZ anomaly. (3) The trade winds anomaly plays a decisive role in the strength and phase transition of the ENSO cycle, which results in the sea level tilting, provides an initial potential energy to the mixed layer water oscillation, and causes the opposite thermocline displacement between the west side and east side of the equator and also between the equator and 12°N of the North Pacific basin, therefore determines the amplitude and route for ENSO cycle. The ITCZ anomaly has some effects on the phase transition. (4) The thermal anomaly of the tropical western Pacific causes the wind stress anomaly and extends eastward along the equator accompanied with the mixed layer water oscillation in the equatorial Pacific, which causes the trade winds anomaly and produces the anomalous wind stress and the corresponding divergence in favor to conduce the oscillation, which in turn intensifies the oscillation. The coupled system of ocean-atmosphere interactions and the inertia gravity of the mixed layer water oscillation provide together a phase-switching mechanism and interannual memory for the ENSO cycle. In conclusion, the ENSO cycle essentially is an inertial oscillation of the mixed layer water induced by both the trade winds anomaly and the coupled ocean-atmosphere interaction in the tropical Pacific basin between the equator and 12°N. When the force produced by the coupled ocean-atmosphere interaction is larger than or equal to the resistance caused by the mixed layer water oscillation, the oscillation will be stronger or maintain as it is, while when the force is less than the resistance, the oscillation will be weaker, even break.
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DOI：
10.1002/joc.986
发表时间：
2004-02
期刊：
International Journal of Climatology
影响因子：
--
作者：
W. Qian;Yafen Zhu;Jianyin Liang
通讯作者：
W. Qian;Yafen Zhu;Jianyin Liang
DOI：
--
发表时间：
2003
期刊：
Journal of Tropical Oceanography
影响因子：
--
作者：
Zhao Yong-pin
通讯作者：
Zhao Yong-pin
影响因子：
3.1
作者：
T. Tsuda;T. Inoue;S. Kato;S. Fukao;D. Fritts;T. Vanzandt
通讯作者：
T. Tsuda;T. Inoue;S. Kato;S. Fukao;D. Fritts;T. Vanzandt
影响因子：
3.1
作者：
K. Trenberth;Shyh-C. Chen
通讯作者：
K. Trenberth;Shyh-C. Chen
影响因子：
4.9
作者：
G. Huffman;R. Adler;B. Rudolf;U. Schneider;P. Keehn
通讯作者：
G. Huffman;R. Adler;B. Rudolf;U. Schneider;P. Keehn