The decadal sea level variability observed in the Indian Ocean tide gauge records and its association with global climate modes

2021 ◽  
Vol 198 ◽  
pp. 103427
Author(s):  
J.S. Deepa ◽  
C. Gnanaseelan
Keyword(s):  
Indian Ocean ◽  
Sea Level ◽  
Tide Gauge ◽  
Global Climate ◽  
Ocean Tide ◽  
Tide Gauge Records ◽  
Sea Level Variability ◽  
Climate Modes ◽  
The Indian Ocean

scholarly journals Climate-driven sea level extremes compounded by marine heatwaves in coastal Indonesia

2021 ◽  
Author(s):  
Weiqing Han ◽  
Lei Zhang ◽  
Gerald Meehl ◽  
Shoichiro Kido ◽  
Tomoki Tozuka ◽  
...  
Keyword(s):  
Indian Ocean ◽  
Sea Level Rise ◽  
Sea Level ◽  
Tide Gauge ◽  
Surface Wind ◽  
Tide Gauge Records ◽  
Intraseasonal Oscillations ◽  
The Indian Ocean ◽  
Global Sea Level ◽  
The 1960S

Abstract The low-lying coastal and island regions are vulnerable to sea level rise and extreme events. Compounded by marine heatwaves, sea level extremes have devastating impacts on coastal community and marine ecosystems. As long tide gauge records are sparse, sea level extremes around Indonesia are poorly understood, and the Compound Height-Heat EXtreme (C-HHEX) events remain unexplored. Here we combine in situ and satellite observations with model simulations, to investigate the long-lasting (>1 month) sea level extremes and C-HHEXs along Indonesian coasts of the Indian Ocean since the 1960s. We find that 90% (80%) of the extreme sea level (C-HHEX) events, with a maximum monthly sea level anomaly of 0.45m, are clustered in an 8yr period of 2010-2017, due to anthropogenic global sea level rise and decadal enhancement driven by changing surface winds associated with a combined invigoration of the Indian and Pacific Walker Cells, atmospheric overturning circulations in east-west direction. Remote and local surface wind anomalies associated with negative phases of the Indian Ocean Dipole (IOD) - enhanced by La Niña – drive individual C-HHEX events under a precondition of shallow thermocline (a region of subsurface ocean with temperature decreases rapidly downward). By contrast, winds associated with monsoon and its intraseasonal oscillations force the sea level alone events under a deep thermocline condition. We conclude that the shoaling thermocline in eastern Indian Ocean under anthropogenic warming and global sea level rise favorably precondition the ocean for stronger and more frequent sea level extremes and C-HHEXs, increasing the environmental stress on Indonesia.

Natural decadal sea-level variability in the Indian Ocean: lessons from CMIP models

2019 ◽  
Vol 53 (9-10) ◽  
pp. 5653-5673
Author(s):  
A. G. Nidheesh ◽  
Matthieu Lengaigne ◽  
Jérôme Vialard ◽  
Takeshi Izumo ◽  
A. S. Unnikrishnan ◽  
...  
Keyword(s):  
Indian Ocean ◽  
Sea Level ◽  
Sea Level Variability ◽  
The Indian Ocean

scholarly journals Use of Oceanic Reanalysis to Improve Estimates of Extreme Storm Surge

2019 ◽  
Vol 36 (11) ◽  
pp. 2205-2219 ◽  
Author(s):  
Li Zhai ◽  
Blair Greenan ◽  
Richard Thomson ◽  
Scott Tinis
Keyword(s):  
Sea Level ◽  
Storm Surge ◽  
West Coast ◽  
Large Scale ◽  
Tide Gauge ◽  
Steric Effects ◽  
Tide Gauge Records ◽  
The West ◽  
Sea Level Variability

AbstractA storm surge hindcast for the west coast of Canada was generated for the period 1980–2016 using a 2D nonlinear barotropic Princeton Ocean Model forced by hourly Climate Forecast System Reanalysis wind and sea level pressure. Validation of the modeled storm surges using tide gauge records has indicated that there are extensive areas of the British Columbia coast where the model does not capture the processes that determine the sea level variability on intraseasonal and interannual time scales. Some of the discrepancies are linked to large-scale fluctuations, such as those arising from major El Niño and La Niña events. By applying an adjustment to the hindcast using an ocean reanalysis product that incorporates large-scale sea level variability and steric effects, the variance of the error of the adjusted surges is significantly reduced (by up to 50%) compared to that of surges from the barotropic model. The importance of baroclinic dynamics and steric effects to accurate storm surge forecasting in this coastal region is demonstrated, as is the need to incorporate decadal-scale, basin-specific oceanic variability into the estimation of extreme coastal sea levels. The results improve long-term extreme water level estimates and allowances for the west coast of Canada in the absence of long-term tide gauge records data.

scholarly journals Field surveys and numerical modelling of the 2004 December 26 Indian Ocean tsunami in the area of Mumbai, west coast of India

2020 ◽  
Vol 222 (3) ◽  
pp. 1952-1964 ◽  
Author(s):  
Mohammad Heidarzadeh ◽  
Alexander Rabinovich ◽  
Satoshi Kusumoto ◽  
C P Rajendran
Keyword(s):  
Indian Ocean ◽  
Subduction Zone ◽  
West Coast ◽  
Subduction Zones ◽  
Field Survey ◽  
Tide Gauge ◽  
Indian Ocean Tsunami ◽  
Tide Gauge Records ◽  
Makran Subduction Zone ◽  
The Indian Ocean

ABSTRACT In the aftermath of the 2004 Indian Ocean (Sumatra-Andaman) tsunami, numerous survey teams investigated its effects on various locations across the Indian Ocean. However, these efforts were focused only on sites that experienced major destruction and a high death toll. As a consequence, some Indian Ocean coastal megacities were not examined. Among the cities not surveyed was Mumbai, the principal west coast port and economical capital of India with a population of more than 12 million. Mumbai is at risk of tsunamis from two major subduction zones in the Indian Ocean: the Sumatra–Andaman subduction zone (SASZ) and the Makran subduction zone (MSZ). As a part of the present study, we conducted a field survey of the 2004 Indian Ocean tsunami effects in Mumbai, analysed the available tide gauge records and performed tsunami simulations. Our field survey in 2018 January found run-up heights of 1.6−3.3 m in the Mumbai area. According to our analysis of tide gauge data, tsunami trough-to-crest heights in Okha (550 km to the north of Mumbai) and in Mormugao (410 km to the south of Mumbai) were 46 cm and 108 cm, respectively. Simulations of a hypothetical MSZ Mw 9.0 earthquake and tsunami, together with the Mw 9.1 Sumatra–Andaman earthquake and tsunami, show that the tsunami heights generated in Mumbai by an MSZ tsunami would be significantly larger than those generated by the 2004 Sumatra–Andaman tsunami. This result indicates that future tsunami hazard mitigation for Mumbai needs to be based on a potential large MSZ earthquake rather than an SASZ earthquake.

scholarly journals SEA LEVEL VARIATION AND GEOSTROPHIC CURRENT OF THE SUNDA STRAIT BASED ON TIDAL AND WIND DATA IN YEAR 2008

2011 ◽  
Vol 3 (2) ◽  
Author(s):  
Resni Oktavia ◽  
John Iskandar Pariwono ◽  
Parluhutan Manurung
Keyword(s):  
Indian Ocean ◽  
Sea Level ◽  
Tide Gauge ◽  
High Tide ◽  
Level Variation ◽  
Tidal Forces ◽  
Sea Level Variation ◽  
The Indian Ocean ◽  
Java Sea ◽  
Current Flows

<p>Sea level variation from four tide-gauge data in the Sunda Strait, Indonesia, in the year 2008 has been studied by using Wavelet 1 D Daubechius 1 level 5 type and Fast Fourier Transform methods. The hourly sea level variation in April and November (representing transitional seasonal conditions) is approximately +0.49 m; whereas in January (representing Northwest Monsoon condition) and July (representing Southeast Monsoon condition) can reach up to -0.48 m. In 2008, sea level variation in the Sunda Strait is mainly influenced by the monsoon. Results from this study show that there are at least three phenomena of sea level variations in the Sunda Strait, namely (1) seasonal variation (periodicity between 4-6 months) where it is believed influenced by the Java Sea; (2) intra-seasonal (periodicity between 1-3 months), which is more influenced by the Indian Ocean; and (3) tidal forcing (periodicity between 14-17 days, suggesting fortnightly tidal forces) which propagates from the Indian Ocean into the Sunda Strait. Result from surface geostrophic approximation calculation suggests that during Southeast Monsoon (June-August), monthly mean current flows southwestwardly towards the Indian Ocean with a velocity of 0.14-0.16 m/s. Whereas during Northwest monsoon (December-February), current flows northeastwardly towards the Java Sea with a velocity of 0.14-0.17 m/s. Furthermore, on the daily time scale, tidal current in the Sunda Strait flows into the Java Sea (Indian Ocean) during high tide (low tide) with a velocity ranging from 0.51 to 0.72 m/s (0.48 to 0.51 m/s).</p><p>Keywords: sea level variation, geostrophic approximation, tides, monsoon, Sunda Strait</p>

scholarly journals Consequences of sea level variability and sea level rise for Cuban territory

2015 ◽  
Vol 365 ◽  
pp. 22-27
Author(s):  
M. Hernández ◽  
C. A. Martínez ◽  
O. Marzo
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Coastal Zone ◽  
Tide Gauge ◽  
High Tide ◽  
Tide Gauge Records ◽  
Sea Level Variability ◽  
Mean Sea Level ◽  
Goods And Services ◽  
Sea Level Anomalies

Abstract. The objective of the present paper was to determine a first approximation of coastal zone flooding by 2100, taking into account the more persistent processes of sea level variability and non-accelerated linear sea level rise estimation to assess the main impacts. The annual linear rate of mean sea level rise in the Cuban archipelago, obtained from the longest tide gauge records, has fluctuated between 0.005 cm/year at Casilda and 0.214 cm/year at Siboney. The main sea level rise effects for the Cuban coastal zone due to climate change and global warming are shown. Monthly and annual mean sea level anomalies, some of which are similar to or higher than the mean sea level rise estimated for halfway through the present century, reinforce the inland seawater penetration due to the semi-daily high tide. The combination of these different events will result in the loss of goods and services, and require expensive investments for adaption.

scholarly journals Decadal Sea Level Variations in the Indian Ocean Investigated with HYCOM: Roles of Climate Modes, Ocean Internal Variability, and Stochastic Wind Forcing*

2015 ◽  
Vol 28 (23) ◽  
pp. 9143-9165 ◽  
Author(s):  
Yuanlong Li ◽  
Weiqing Han
Keyword(s):  
Heat Flux ◽  
Indian Ocean ◽  
Sea Level ◽  
Surface Heat Flux ◽  
Internal Variability ◽  
Surface Heat ◽  
Wind Forcing ◽  
Sea Level Variability ◽  
The Indian Ocean ◽  
Sea Level Variations

Abstract In this study decadal (≥10 yr) sea level variations in the Indian Ocean (IO) during 1950–2012 are investigated using the Hybrid Coordinate Ocean Model (HYCOM). The solution of the main run agrees well with observations in the western-to-central IO. Results of HYCOM experiments reveal large spatial variations in the mechanisms of decadal sea level variability. Within the tropical IO (north of 20°S), decadal sea level variations achieve maximum amplitude in the south IO thermocline ridge region. They are predominantly forced by decadal fluctuations of surface wind stress associated with climate variability modes, while the impact of other processes is much smaller. The Somali coast and the western Bay of Bengal are two exceptional regions, where ocean internal (unforced) variability has large contribution. Between 28° and 20°S in the subtropical south IO, surface heat flux and ocean internal variability are the major drivers of decadal sea level variability. Heat budget analysis for the upper 300 m of this region suggests that surface heat flux affects regional thermosteric sea level through both local surface heating and heat transport by ocean circulation. In the southwestern IO south of 30°S, where stochastic winds are strong, stochastic wind forcing and its interaction with ocean internal variability generate pronounced decadal variations in sea level. The comprehensive investigation of decadal sea level variability over the IO from an oceanic perspective will contribute to decadal sea level prediction research, which has a high societal demand.

REVIEW OF TIDE GAUGE RECORDS IN THE INDIAN OCEAN

2009 ◽  
Vol 03 (01) ◽  
pp. 1-15
Author(s):  
HIROYUKI MATSUMOTO ◽  
YUICHIRO TANIOKA ◽  
YUICHI NISHIMURA ◽  
YOSHINOBU TSUJI ◽  
YUICHI NAMEGAYA ◽  
...  
Keyword(s):  
Indian Ocean ◽  
Tide Gauge ◽  
Indian Ocean Tsunami ◽  
Tide Gauges ◽  
Tide Gauge Records ◽  
Historical Tsunami ◽  
Tide Level ◽  
History Of ◽  
The Indian Ocean ◽  
Systematic Collection

According to the NOAA earthquake database, at least 31 events have been found in the Indian Ocean in terms of tsunami event since 1900, most of which occurred along the Sunda Trench. In this study, we review the history of tide level measurements and their datasets archives in Thailand, Indonesia, India, and Australia. We collected tide gauge paper charts recording historical tsunamis including the 2004 Indian Ocean tsunami in those countries. As a result, systematic collection of historical tsunami records by tide gauges in the Indian Ocean has been difficult, because few tsunamigenic earthquakes occurred in the Indian Ocean during the instrumentally observed period.

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