A study of biases in simulation of the Indian Ocean basin mode and its capacitor effect in CMIP3/CMIP5 models

2015 ◽  
Vol 46 (1-2) ◽  
pp. 205-226 ◽  
Author(s):  
Weichen Tao ◽  
Gang Huang ◽  
Kaiming Hu ◽  
Hainan Gong ◽  
Guanhuan Wen ◽  
...  
Keyword(s):  
Indian Ocean ◽  
Ocean Basin ◽  
Cmip5 Models ◽  
Indian Ocean Basin Mode ◽  
Basin Mode ◽  
The Indian Ocean

Interdecadal Strengthening in the Independent Relationship Between the East Asian Summer Monsoon and the Indian Ocean Basin Mode around the Early 1990s

2021 ◽  
pp. 1-42
Author(s):  
KUI LIU ◽  
LIAN-TONG ZHOU ◽  
ZHIBIAO WANG ◽  
YONG LIU ◽  
XIAOXUE YIN
Keyword(s):  
Indian Ocean ◽  
East Asian Summer Monsoon ◽  
Asian Summer Monsoon ◽  
East Asian ◽  
Ocean Basin ◽  
Indian Ocean Basin Mode ◽  
Basin Mode ◽  
The Indian Ocean ◽  
Asian Summer ◽  
The Relationship

AbstractThis study conducts correlation and regression analyses of the JRA-55 reanalysis data and observational rainfall datasets from China’s National Climate Center. The analyses reveal that interdecadal enhancement in the relationship between the East Asian summer monsoon (EASM) and the Indian Ocean Basin mode (IOBM) after the early 1990s, and the diminished correlation between the EASM and the Niño-3 index. The analyses also reveal that the relationship between EASM-related rainfall/circulation with IOBM also experienced an interdecadal shift at the same time. During the first epoch (1977–1989), EASM-related rainfall was correlated significantly with the Niño-3 index, and accompanied by a Pacific–Japan-like anomaly pattern of horizontal winds. In a subsequent epoch (1994–2014), EASM-related rainfall was correlated significantly with IOBM, and accompanied by a meridional dipole pattern in the horizontal winds. After the 1990s, IOBM exerted influence on EASM through land–sea thermal contrast, and the critical land area was the region 33°–47°N, 110°–140°E. The interdecadal strengthening in the EASM–IOBM linkage around the early 1990s may be attributable to a faster rate of decay of El Niño after the 1990s.

Linking Observations of the Asian Monsoon to the Indian Ocean SST: Possible Roles of Indian Ocean Basin Mode and Dipole Mode

2010 ◽  
Vol 23 (21) ◽  
pp. 5889-5902 ◽  
Author(s):  
Jianling Yang ◽  
Qinyu Liu ◽  
Zhengyu Liu
Keyword(s):  
Indian Ocean ◽  
Atmospheric Circulation ◽  
Summer Monsoon ◽  
Asian Monsoon ◽  
Asian Summer Monsoon ◽  
Ocean Basin ◽  
Indian Ocean Basin Mode ◽  
Basin Mode ◽  
The Indian Ocean ◽  
Asian Summer

Abstract The authors investigate the relationship between sea surface temperature (SST) in the tropical Indian Ocean (TIO) and the seasonal atmosphere circulation in the Asian monsoon region (AMR) using the maximum covariance analyses (MCAs). The results show that the Asian monsoon circulation is significantly correlated with two dominant SST anomaly (SSTA) modes: the Indian Ocean Basin mode (IOB) and the Indian Ocean dipole mode (IOD). The peak SSTA of the IOB appears in spring and has a much stronger relationship with the Asian summer monsoon than the peak of the IOD does, whereas the peak SSTA for the IOD appears in fall and shows a stronger link to the Asian winter monsoon than to the Asian summer monsoon. In addition, the IOB in spring has a relatively stronger link with the atmospheric circulation in summer than in other seasons. The large-scale atmospheric circulation and SSTA patterns of the covariability of the first two dominant MCA modes are described. For the first MCA mode, a warm IOB, persists from spring to summer, and the atmospheric circulation is enhanced by the establishment of the climatological summer monsoon. The increased evaporative moisture associated with the warm IOB is transported to South Asia by the climatological summer monsoon, which increases the moisture convergence toward this region, leading to a significant increase in summer monsoon precipitation. For the second MCA mode, a positive IOD possibly corresponds to a weaker Indian winter monsoon and more precipitation over the southwestern and eastern equatorial TIO.

scholarly journals Modulation of the Impacts of the Indian Ocean Basin Mode on Tropical Cyclones over the Northwest Pacific during the Boreal Summer by La Niña Modoki

2019 ◽  
Vol 32 (11) ◽  
pp. 3313-3326 ◽  
Author(s):  
Jingliang Huangfu ◽  
Wen Chen ◽  
Ronghui Huang ◽  
Juan Feng
Keyword(s):  
Indian Ocean ◽  
Ocean Basin ◽  
La Niña ◽  
Sea Surface ◽  
Boreal Summer ◽  
Northwest Pacific ◽  
Indian Ocean Basin Mode ◽  
La Nina ◽  
Basin Mode ◽  
The Indian Ocean

Abstract This paper investigates how La Niña Modoki modulates the impacts of the warm Indian Ocean basin mode (IOBM) on the boreal summer climate and the genesis of tropical cyclones (TCs) over the northwest Pacific (NWP). The results showed that the influence of the Indian Ocean sea surface temperature (SST) on TC genesis is the primary mechanism during the boreal summer, while La Niña Modoki exerts a secondary influence. However, although the summertime index of the IOBM shows a high negative correlation with the number of TCs generated over the NWP, warm IOBM events without La Niña Modoki have only limited influences on the boreal summertime circulations and TC genesis. The present study showed that when warm IOBM events and La Niña Modoki coexisted, the average location of TC genesis shifted westward, and the annual number of generated TCs substantially decreased. La Niña Modoki–related cold sea surface temperature anomalies over the central Pacific further suppressed convective activities over the eastern NWP compared with warm IOBM events without La Niña Modoki. Upper-level convergence and enlarged tropospheric vertical wind shears both contributed to the weakening of the low-level relative vorticity in the coupled cases, leading to a suppressed NWP monsoon trough. Additionally, together with the weaker moisture supply, the impacts of warm IOBM cases were significantly enhanced under the modulation of La Niña Modoki, leading to poorer TC genesis conditions over the eastern NWP. In addition, the energy conversion processes in the aforementioned modulation showed that joint cases will provide fewer initial disturbance seedlings for TC genesis. These results are useful for further understanding the role of warm IOBM cases in TC genesis over the NWP.

Understanding the Weakening Relationship of the Pacific Decadal Oscillation and Indian Ocean Basin Mode During Boreal Winter

2021 ◽  
Author(s):  
Jin-Sil Hong ◽  
Sang-Wook Yeh ◽  
Young-Min Yang ◽  
Young-Kwon Lim ◽  
Kyu-Myong Kim
Keyword(s):  
Indian Ocean ◽  
Pacific Decadal Oscillation ◽  
Climate Model ◽  
Ocean Basin ◽  
Boreal Winter ◽  
Indian Ocean Basin Mode ◽  
The Pacific ◽  
Basin Mode ◽  
Relationship Of

Abstract While it is known that the Pacific Decadal Oscillation (PDO) leads the Indian Ocean Basin Mode (IOBM) with the same phase via the atmospheric bridge, we found that the relationship of PDO-IOBM during boreal winter is not stationary. Here, we investigated the PDO-IOBM relationship changes on low-frequency timescales by analyzing the observations, a long-term simulation of climate model with its large ensembles as well as the pacemaker experiments. A long-term simulation of climate model with its large ensemble simulations indicated that the non-stationary relationship of PDO-IOBM is intrinsic in a climate system and it could be at least partly due to internal climate variability. In details, we compared the PDO structures during the entire period with those during the period when the PDO-IOBM relationship was weak (i.e., 1976-2006). We found that the structures of sea surface temperature (SST) as well as its associated tropical Pacific convective forcing during the negative phase of PDO for 1976-2006 are far away from the typical structures of the negative PDO phase during the entire period, which were responsible for the weakening relationship of the PDO-IOBM in the observation. The results of the two pacemaker experiments support that a non-stationary relationship of PDO-IOBM is primarily due to the SST forcing in the Pacific.

Response of the Indian Ocean Basin Mode and Its Capacitor Effect to Global Warming*

2011 ◽  
Vol 24 (23) ◽  
pp. 6146-6164 ◽  
Author(s):  
Xiao-Tong Zheng ◽  
Shang-Ping Xie ◽  
Qinyu Liu
Keyword(s):  
Global Warming ◽  
Indian Ocean ◽  
El Niño ◽  
El Nino ◽  
Ocean Basin ◽  
Northwest Pacific ◽  
Geophysical Fluid Dynamics Laboratory ◽  
Indian Ocean Basin Mode ◽  
Easterly Wind ◽  
The Indian Ocean

Abstract The development of the Indian Ocean basin (IOB) mode and its change under global warming are investigated using a pair of integrations with the Geophysical Fluid Dynamics Laboratory Climate Model version 2.1 (CM2.1). In the simulation under constant climate forcing, the El Niño–induced warming over the tropical Indian Ocean (TIO) and its capacitor effect on summer northwest Pacific climate are reproduced realistically. In the simulation forced by increased greenhouse gas concentrations, the IOB mode and its summer capacitor effect are enhanced in persistence following El Niño, even though the ENSO itself weakens in response to global warming. In the prior spring, an antisymmetric pattern of rainfall–wind anomalies and the meridional SST gradient across the equator strengthen via increased wind–evaporation–sea surface temperature (WES) feedback. ENSO decays slightly faster in global warming. During the summer following El Niño decay, the resultant decrease in equatorial Pacific SST strengthens the SST contrast with the enhanced TIO warming, increasing the sea level pressure gradient and intensifying the anomalous anticyclone over the northwest Pacific. The easterly wind anomalies associated with the northwest Pacific anticyclone in turn sustain the SST warming over the north Indian Ocean and South China Sea. Thus, the increased TIO capacitor effect is due to enhanced air–sea interaction over the TIO and with the western Pacific. The implications for the observed intensification of the IOB mode and its capacitor effect after the 1970s are discussed.

The Interdecadal Reverse of the Relationship and Feedback Mechanism between Sea Surface Temperature and Evaporation over the Indian Ocean during Boreal Autumn

2020 ◽  
Vol 33 (23) ◽  
pp. 10205-10219
Author(s):  
Bicheng Huang ◽  
Tao Su ◽  
Yongping Wu ◽  
Guolin Feng
Keyword(s):  
Indian Ocean ◽  
Surface Temperature ◽  
Sea Surface Temperature ◽  
Indian Ocean Dipole ◽  
Interaction Mechanism ◽  
Ocean Basin ◽  
Sea Surface ◽  
Indian Ocean Basin Mode ◽  
Low Level ◽  
The Indian Ocean

AbstractThe linkage between sea surface temperature (SST) and evaporation (EVP) plays an important role in air–sea interactions. In this study, the interaction mechanism of SST and EVP during boreal autumn was studied using correlation analysis, composite analysis, the EVP decomposition method, and singular value decomposition. The results showed that the correlation between SST and EVP in the Indian Ocean was reversed from positive to negative in the late 1990s. The significant positive SST–EVP relationship was attributed to the Indian Ocean basin mode forcing upon EVP during 1980–90. The decrease in wind speed–induced EVP and SST warming led to a significant negative SST–EVP relationship during 2005–15. Moreover, the negative SST–EVP correlation occurred when the Indian Ocean dipole (IOD) and subtropical Indian Ocean dipole (SIOD) exhibited inverse phases. The low-level moisture–EVP–SST feedback dominated the negative SST–EVP correlation in the negative IOD and positive SIOD (nIOD–pSIOD) pattern, whereas the wind–EVP–SST feedback played the leading role in the positive IOD and negative SIOD (pIOD–nSIOD) pattern. The EVP anomalies induced by the low-level anomalous anticyclone and cyclone were the main causes of the SST anomalies with inverse phases of the IOD and SIOD. The correlation between the SST and EVP reversal from positive to negative implies that the effect of the atmosphere on the ocean is as important as the external forcing of the ocean on the atmosphere.

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