The spatial and temporal differences of upper ocean in tropical Pacific during the “triple-dip” La Niña of 2020-2023

doi:10.3969/j.issn.1001-909X.2024.04.002

Abstract

Abstract:

The occurrence of a “triple-dip” La Ni?a event is historically rare, yet it has exerted profound impacts on global weather and climate systems. To enhance the understanding of the causes of multiple La Ni?a events and improve the prediction capabilities for weather and climate, a comparative analysis of the ocean-atmosphere processes in the tropical Pacific during the 2020-2023 “triple-dip” La Ni?a period was conducted based on multiple sets of observational and reanalysis data, employing composite analysis and other methods. Results showed that: The peak of the 2020 La Ni?a event occurred in winter and lasted the longest among this “triple-dip” La Ni?a events; the peak of the 2021 La Ni?a event also occurred in winter, with the cold anomaly centered near the eastern Pacific, classified as an “Eastern Pacific” type; the peak of the 2022 La Ni?a event occurred in autumn, relatively weaker in intensity and the shortest in duration, with the cold anomaly centered in the central Pacific, classified as a “Central Pacific” type. Further research revealed a coupling relationship between zonal wind and sea surface temperature (SST) variations. However, during this “triple-dip” La Ni?a period, the intensity and location of the eastward wind anomalies showed little variation across different La Ni?a events. In contrast, subsurface SST changes align with changes in SST anomaly centers, it may be a crucial factor influencing the intensity and type differences among this “triple-dip” La Ni?a events. Although eastward-propagating Kelvin waves had a certain impact on the ocean system, but their propagation speeds and intensities exhibited minimal variations during this “triple-dip” La Ni?a events. Additionally, the study found that variations in the growth rate of warm water volume contributed to the differences in La Ni?a intensities, while the meridional convergence and divergence of warm water led to the seasonal phase-locking phenomenon of La Ni?a events.

Key words: sea surface temperature anomaly, subsurface sea temperature, warm water volume, El Ni?o-Southern Oscillation, climate change, air-sea interaction, multiyear La Ni?a, climate prediction

CLC Number:

P732

CHEN Cong, XU Chuyue, QIN Jianhuang, KANG Yanyan, WANG Guifen. The spatial and temporal differences of upper ocean in tropical Pacific during the “triple-dip” La Niña of 2020-2023[J]. Journal of Marine Sciences, 2024, 42(4): 12-20.

Figures/Tables 7

Fig.1 The Ni?o indices during January 2020 to May 2023 (The shading indicates the duration of the La Ni?a event.)

Fig.2 The spatial distribution of boreal winter SST anomaly and surface wind anomaly during 2020-2022

Fig.3 Surface zonal wind anomaly (a) and averaged SST anomaly (b) between 5°N and 5°S over the tropical Pacific from January 2020 to May 2023

Fig.4 The subsurface ocean temperature anomaly and the 20 ℃ isotherm depth between 2°S and 2°N over the tropical Pacific (The purple line represents the mean value of 20 ℃ isotherm depth in winter of each year and the black thick line indicats the climatological state of the 20 ℃ isotherm depth.)

Fig.5 The averaged 20 ℃ isotherm depth anomaly between 2°N and 2°S over the tropical Pacific from January 2020 to May 2023 (Positive value indicates deepening thermocline, while negative value indicates shallowing thermocline.)

Fig.6 The warm water volume anomaly from January 2020 to May 2023 (The red dashed line indicates the beginning of La Ni?a event.)

Fig.7 Spatial patterns and time series of 20 ℃ isotherm depth in the tropical Pacific from January 2020 to May 2023

References 46

[1]	ZHENG F, FANG X H, ZHU J, et al. Modulation of Bjerknes feedback on the decadal variations in ENSO predictability[J]. Geophysical Research Letters, 2016, 43(24): 12560-12568.
[2]	CHIKAMOTO Y, TANIMOTO Y. Air-sea humidity effects on the generation of tropical Atlantic SST anomalies during the ENSO events[J]. Geophysical Research Letters, 2006, 33(19): L19702.
[3]	JOHNSON S J, STOCKDALE T N, FERRANTI L, et al. SEAS5: The new ECMWF seasonal forecast system[J]. Geoscientific Model Development, 2019, 12(3): 1087-1117. DOI
[4]	MACLACHLAN C, ARRIBAS A, PETERSON K A, et al. Global seasonal forecast system version 5 (GloSea5): A high-resolution seasonal forecast system[J]. Quarterly Journal of the Royal Meteorological Society, 2015, 141(689): 1072-1084.
[5]	O’LENIC E A, UNGER D A, HALPERT M S, et al. Developments in operational long-range climate prediction at CPC[J]. Weather and Forecasting, 2008, 23(3): 496-515.
[6]	MCPHADEN M, SANTOSO A, CAI W. El Niño Southern Oscillation in a changing climate[M]. [S.l.]: Wiley, 2020.
[7]	TIMMERMANN A, AN S I, KUG J S, et al. El Niño-Southern Oscillation complexity[J]. Nature, 2018, 559: 535-545.
[8]	DINEZIO P N, DESER C, OKUMURA Y, et al. Predictability of 2-year La Niña events in a coupled general circulation model[J]. Climate Dynamics, 2017, 49(11): 4237-4261.
[9]	HU Z Z, KUMAR A, XUE Y, et al. Why were some La Niñas followed by another La Niña?[J]. Climate Dynamics, 2014, 42: 1029-1042.
[10]	MIN S K, CAI W J, WHETTON P. Influence of climate variability on seasonal extremes over Australia[J]. Journal of Geophysical Research: Atmospheres, 2013, 118(2): 643-654.
[11]	LUO J J, LIU G Q, HENDON H, et al. Inter-basin sources for two-year predictability of the multi-year La Niña event in 2010-2012[J]. Scientific Reports, 2017, 7: 2276.
[12]	KOSAKA Y, XIE S P. Recent global-warming hiatus tied to equatorial Pacific surface cooling[J]. Nature, 2013, 501: 403-407.
[13]	ENGLAND M H, MCGREGOR S, SPENCE P, et al. Recent intensification of wind-driven circulation in the Pacific and the ongoing warming hiatus[J]. Nature Climate Change, 2014, 4: 222-227.
[14]	WATANABE M, SHIOGAMA H, TATEBE H, et al. Contribution of natural decadal variability to global warming acceleration and hiatus[J]. Nature Climate Change, 2014, 4: 893-897.
[15]	WANG C Z, DESER C, YU J Y, et al. El Niño and Southern Oscillation (ENSO): A review[M]//GLYNN P W, MANZELLO D P, ENOCHS I C. Coral reefs of the eastern tropical Pacific. Dordrecht: Springer, 2017: 85-106.
[16]	GODDARD L, PHILANDER S G. The energetics of El Niño and La Niña[J]. Climate, 2000, 13, 1496-1516.
[17]	WYRTKI K. El Niño—The dynamic response of the equatorial Pacific ocean to atmospheric forcing[J]. Journal of Physical Oceanography, 1975, 5(4): 572-584.
[18]	WYRTKI K. Water displacements in the Pacific and the genesis of El Niño cycles[J]. Journal of Geophysical Research: Oceans, 1985, 90(C4): 7129-7132.
[19]	JIN F F. An equatorial ocean recharge paradigm for ENSO: part I: Conceptual model[J]. Journal of the Atmospheric Sciences, 1997, 54(7): 811-829.
[20]	JIN F F. An equatorial ocean recharge paradigm for ENSO: part II: A stripped-down coupled model[J]. Journal of the Atmospheric Sciences, 1997, 54(7): 830-847.
[21]	ZHANG R H, GAO C, FENG L C. Recent ENSO evolution and its real-time prediction challenges[J]. National Science Review, 2022, 9(4): nwac052.
[22]	CAI W J, WANG G J, SANTOSO A, et al. Increased frequency of extreme La Niña events under greenhouse warming[J]. Nature Climate Change, 2015, 5: 132-137.
[23]	GAO Y P, FAN K, XU Z Q. Causes of the unprecedented month-to-month persistent extreme heat event over South China in early summer 2020: Role of sea surface tempera-ture anomalies in the tropical indo-pacific region[J]. Journal of Geophysical Research: Atmospheres, 2023, 128: e2022JD038422.
[24]	何慧根, 张驰, 吴遥, 等. 重庆夏季高温干旱特征及其对拉尼娜事件的响应[J]. 干旱气象, 2023, 41(6):873-883.
	HE H G, ZHANG C, WU Y, et al. Characteristics of high temperature and drought during summer in Chongqing and its response to La Niña event[J]. Journal of Arid Meteorology, 2023, 41(6): 873-883.
[25]	ZHENG F, YUAN Y, DING Y H, et al. The 2020/21 extremely cold winter in China influenced by the synergistic effect of La Niña and warm Arctic[J]. Advances in Atmos-pheric Sciences, 2022, 39(4): 546-552.
[26]	BIAN Y J, SUN P, ZHANG Q, et al. Amplification of non-stationary drought to heatwave duration and intensity in eastern China: Spatiotemporal pattern and causes[J]. Journal of Hydrology, 2022, 612: 128154.
[27]	ZHENG F, LIU J P, FANG X H, et al. The predictability of ocean environments that contributed to the 2020/21 extreme cold events in China: 2020/21 La Niña and 2020 Arctic sea ice loss[J]. Advances in Atmospheric Sciences, 2022, 39(4): 658-672.
[28]	任宏利, 王润, 翟盘茂, 等. 超强厄尔尼诺事件海洋学特征分析与预测回顾[J]. 气象学报, 2017, 75(1):1-18.
	REN H L, WANG R, ZHAI P M, et al. Upper-ocean dynamical features and prediction of the super El Niño in 2015/2016: A comparison with 1982/1983 and 1997/1998[J]. Acta Meteorologica Sinica, 2017, 75(1):1-18.
[29]	JEONG H, PARK H S, CHOWDARY J S, et al. Triple-dip La Niña contributes to Pakistan flooding and Southern China drought in summer 2022[J]. Bulletin of the American Meteorological Society, 2023, 104(9): 1570-1586.
[30]	WANG Z Q, LUO H L, YANG S. Different mechanisms for the extremely hot central-eastern China in July-August 2022 from a Eurasian large-scale circulation perspective[J]. Environmental Research Letters, 2023, 18(2): 024023.
[31]	RIPPLE W J, WOLF C, GREGG J W, et al. World scientists’ warning of a climate emergency 2022[J]. BioScience, 2022, 72(12): 1149-1155.
[32]	郑飞, 张小娟, 曹庭伟. 西太平洋暖池海洋热浪在2020—2022三年拉尼娜事件爆发背景下的演变特征、爆发机制及其影响研究[J]. 大气科学, 2024, 48(1):376-390.
	ZHENG F, ZHANG X J, CAO T W. Analysis of evolution characteristics, physical mechanisms, and impacts of marine heat waves in the Western Pacific warm pool under the background of triple-year La Niña from 2020 to 2022[J]. Chinese Journal of Atmospheric Sciences, 2024, 48(1): 376-390.
[33]	FANG X H, ZHENG F, LI K X, et al. Will the historic southeasterly wind over the equatorial Pacific in March 2022 trigger a third-year La Niña event?[J]. Advances in Atmospheric Sciences, 2023, 40(1): 6-13.
[34]	LI X F, HU Z Z, TSENG Y H, et al. A historical perspective of the La Niña event in 2020/2021[J]. Journal of Geophysical Research: Atmospheres, 2022, 127(7): e2021JD035546.
[35]	ZHENG F, FENG L S, ZHU J. An incursion of off-equatorial subsurface cold water and its role in triggering the “double dip” La Niña event of 2011[J]. Advance in Atmospheric Sciences, 2015, 32: 731-742.
[36]	JIANG S, ZHU C W, HU Z Z, et al. Triple-dip La Niña in 2020-23: Understanding the role of the annual cycle in tropical Pacific SST[J]. Environmental Research Letters, 2023, 18(8): 084002.
[37]	MASUDA S, AWAJI T, TOYODA T, et al. Temporal evolution of the equatorial thermocline associated with the 1991-2006 ENSO[J]. Journal of Geophysical Research: Oceans, 2009, 114(C3): C03015.
[38]	WANG B, WU R G, LUKAS R. Roles of the western North Pacific wind variation in thermocline adjustment and ENSO phase transition[J]. Journal of the Meteorological Society of Japan Ser II, 1999, 77(1): 1-16.
[39]	LI M T, CAO Z Y, GORDON A L, et al. Roles of the Indo-Pacific subsurface Kelvin waves and volume transport in prolonging the triple-dip 2020-2023 La Niña[J]. Environmental Research Letters, 2023, 18: 104043.
[40]	KIM K Y, KIM Y Y. Mechanism of Kelvin and Rossby waves during ENSO events[J]. Meteorology and Atmospheric Physics, 2002, 81(3): 169-189.
[41]	MEINEN C S, MCPHADEN M J. Observations of warm water volume changes in the equatorial Pacific and their relationship to El Niño and La Niña[J]. Journal of Climate, 2000, 13(20): 3551-3559.
[42]	GENG T, JIA F, CAI W J, et al. Increased occurrences of consecutive La Niña events under global warming[J]. Nature, 2023, 619: 774-781.
[43]	CHEN M N, GAO C, ZHANG R H. How the central-western equatorial Pacific easterly wind in early 2022 affects the third-year La Niña occurrence[J]. Climate Dynamics, 2024, 62(5): 3047-3066.
[44]	GAO C, ZHOU L, ZHANG R H. A transformer-based deep learning model for successful predictions of the 2021 second-year La Niña condition[J]. Geophysical Research Letters, 2023, 50: e2023GL104034.
[45]	高川, 陈茂楠, 周路, 等. 2020-2021年热带太平洋持续性双拉尼娜事件的演变[J]. 中国科学:地球科学, 2022, 52(12): 2353-2372.
	GAO C, CHEN M N, ZHOU L, et al. The 2020-2021 prolonged La Niña evolution in the tropical Pacific[J]. Science China Earth Sciences, 2022, 65(12): 2248-2266.
[46]	HASAN N A, CHIKAMOTO Y, MCPHADEN M J. The influence of tropical basin interactions on the 2020-2022 double-dip La Niña[J]. Frontiers in Climate, 2022, 4: 1001174.