Prediction of nontidal sea level variations in the Persian Gulf using data assimilation techniques

2018 ◽  
Vol 60 (3) ◽  
pp. 340-355 ◽  
Author(s):  
Naghmeh Afshar-Kaveh ◽  
Abbas Ghaheri ◽  
Vahid Chegini ◽  
Mostafa Nazarali
Keyword(s):  
Data Assimilation ◽  
Sea Level ◽  
Persian Gulf ◽  
Sea Level Variations ◽  
Using Data ◽  
The Persian Gulf

scholarly journals Relationship between the Persian Gulf Sea-Level Fluctuations and Meteorological Forcing

2020 ◽  
Vol 8 (4) ◽  
pp. 285
Author(s):  
Naghmeh Afshar-Kaveh ◽  
Mostafa Nazarali ◽  
Charitha Pattiaratchi
Keyword(s):  
Sea Level ◽  
Persian Gulf ◽  
Atmospheric Pressure ◽  
Tide Gauge ◽  
Low Frequency ◽  
Northern Coast ◽  
Meteorological Forcing ◽  
Sea Level Fluctuations ◽  
Coastal Sea ◽  
The Persian Gulf

Sea-level data from six tide gauge stations along the northern coast of the Persian Gulf were analyzed both in time and frequency domain to evaluate meteorological forcing. Spectral analyses indicated that mixed, predominantly semi-diurnal tides were dominant at all stations, but low-frequency fluctuations correlated well with atmospheric pressure and wind components. Non-tidal sea-level fluctuations up to 0.75 m were observed along the northern coasts of the Gulf due to the combined action of lower atmospheric pressure and cross-shore wind. Coherency between low-frequency sea-level records and mean sea-level pressure indicated that the latter usually leads to sea-level fluctuations between 1 and 6.4 days. In contrast, the same analysis on the wind velocity and sea level revealed that the former lags between 3 and 13 days. The effect of wind stress on coastal sea-level variations was higher compared with the effect of atmospheric pressure. Concurrent analysis of low-pass-filtered sea-level records proved that the non-tidal wave moves from west to east along the northern coasts of the Persian Gulf.

scholarly journals Intraseasonal Sea-Level Variability in the Persian Gulf

2021 ◽  
Author(s):  
Christopher G Piecuch ◽  
Ichiro Fukumori ◽  
Rui M Ponte
Keyword(s):  
Sea Level ◽  
Persian Gulf ◽  
Sea Level Variability ◽  
The Persian Gulf

Eustatic control of late Quaternary sea-level change in the Arabian/Persian Gulf

2014 ◽  
Vol 82 (1) ◽  
pp. 175-184 ◽  
Author(s):  
Thomas Stevens ◽  
Matthew J. Jestico ◽  
Graham Evans ◽  
Anthony Kirkham
Keyword(s):  
Sea Level ◽  
Persian Gulf ◽  
Late Quaternary ◽  
Osl Dating ◽  
Sea Level Changes ◽  
Last Interglacial ◽  
Coastal Evolution ◽  
Last Glacial ◽  
Sea Level Variations ◽  
The Last Glacial

AbstractAccurate sea-level reconstruction is critical in understanding the drivers of coastal evolution. Inliers of shallow marine limestone and aeolianite are exposed as zeugen (carbonate-capped erosional remnants) on the southern coast of the Arabian/Persian Gulf. These have generally been accepted as evidence of a eustatically driven, last-interglacial relative sea-level highstand preceded by a penultimate glacial-age lowstand. Instead, recent optically stimulated luminescence (OSL) dating suggests a last glacial age for these deposits, requiring >100 m of uplift since the last glacial maximum in order to keep pace with eustatic sea-level rise and implying the need for a wholesale revision of tectonic, stratigraphic and sea-level histories of the Gulf. These two hypotheses have radically different implications for regional neotectonics and land–sea distribution histories. Here we test these hypotheses using OSL dating of the zeugen formations. These new ages are remarkably consistent with earlier interpretations of the formations being last interglacial or older in age, showing that tectonic movements are negligible and eustatic sea-level variations are responsible for local sea-level changes in the Gulf. The cause of the large age differences between recent studies is unclear, although it appears related to large differences in the measured accumulated dose in different OSL samples.

Conflict and Public Opinion: Rallying Effects of the Persian Gulf War

1994 ◽  
Vol 71 (1) ◽  
pp. 20-31 ◽  
Author(s):  
Douglas M. McLeod ◽  
William P. Eveland ◽  
Nancy Signorielli
Keyword(s):  
Persian Gulf ◽  
Public Support ◽  
Gulf War ◽  
Persian Gulf War ◽  
Conflict Theory ◽  
Potential Threat ◽  
Using Data ◽  
One Year ◽  
The Persian Gulf ◽  
The Impact

This study examines the dissipation of “rally effects” in the aftermath of the Persian Gulf War using data from a panel of 167 New Castle County (Delaware) respondents interviewed during the war and one year later. Public support for the war and confidence in the president, Congress, and the military declined significantly. Hostility toward antiwar protesters also diminished. The study combines the “rally around the flag” literature from political science and functional conflict theory from sociology to explain the impact of this major external conflict on support for government institutions and intolerance for elements perceived as a potential threat.

scholarly journals Intraseasonal Sea-Level Variability in the Persian Gulf

2021 ◽  
Author(s):  
Christopher G. Piecuch ◽  
Ichiro Fukumori ◽  
Rui M. Ponte
Keyword(s):  
Indian Ocean ◽  
Sea Level ◽  
Persian Gulf ◽  
Large Scale ◽  
Intraseasonal Variability ◽  
Barometric Pressure ◽  
Freshwater Flux ◽  
Eof Analysis ◽  
Gulf Of Oman ◽  
The Persian Gulf

AbstractSatellite observations are used to establish the dominant magnitudes, scales, and mechanisms of intraseasonal variability in ocean dynamic sea level () in the Persian Gulf over 2002–2015. Empirical orthogonal function (EOF) analysis applied to altimetry data reveals a basin-wide, single-signed intraseasonal fluctuation that contributes importantly to variance in the Persian Gulf at monthly to decadal timescales. An EOF analysis of Gravity Recovery and Climate Experiment (GRACE) observations over the same period returns a similar large-scale mode of intraseasonal variability, suggesting that the basin-wide intraseasonal variation has a predominantly barotropic nature. A linear barotropic theory is developed to interpret the data. The theory represents Persian-Gulf-average () in terms of local freshwater flux, barometric pressure, and wind stress forcing, as well as at the boundary in the Gulf of Oman. The theory is tested using a multiple linear regression with these freshwater flux, barometric pressure, wind stress, and boundary quantities as input, and as output. The regression explains 70%±79% (95% confidence interval) of the intraseasonal variance. Numerical values of regression coefficients computed empirically from the data are consistent with theoretical expectations from first principles. Results point to a substantial non-isostatic response to surface loading. The Gulf of Oman boundary condition shows lagged correlation with upstream along the Indian Subcontinent, Maritime Continent, and equatorial Indian Ocean, suggesting a large-scale Indian-Ocean influence on intraseasonal variation mediated by coastal and equatorial waves, and hinting at potential predictability. This study highlights the value of GRACE for understanding sea level in an understudied marginal sea.

scholarly journals The Study of SST Optimization Using Nudging Scheme in Data Assimilation Method (Case Study: the Persian Gulf)

2017 ◽  
Vol 8 (29) ◽  
pp. 17-24
Author(s):  
Mahmud Reza Abbasi ◽  
Vahid Chegini ◽  
Masoud Sadrinasab ◽  
Seyed Mostafa Siadatmousavi ◽  
◽  
...  
Keyword(s):  
Data Assimilation ◽  
Persian Gulf ◽  
The Persian Gulf

Holocene sea-level changes of the Persian Gulf

2020 ◽  
Author(s):  
Gholamreza Hosseinyar ◽  
Reza Behbahani ◽  
Reza Moussavi-Harami ◽  
Razyeh Lak ◽  
Antoon Kuijpers
Keyword(s):  
Sea Level ◽  
Persian Gulf ◽  
Sea Level Changes ◽  
The Persian Gulf ◽  
Holocene Sea Level

Intraseasonal Variability in the Persian Gulf Revealed by GRACE and Altimetry

2020 ◽  
Author(s):  
Christopher Piecuch ◽  
Rui Ponte ◽  
Ichiro Fukumori
Keyword(s):  
Indian Ocean ◽  
Sea Level ◽  
Persian Gulf ◽  
Large Scale ◽  
Freshwater Flux ◽  
Ocean Bottom ◽  
Level Variation ◽  
Gulf Of Oman ◽  
Sea Level Variation ◽  
The Persian Gulf

<p>The Persian Gulf is a semi-enclosed marginal sea of the Indian Ocean. It connects to the Arabian Sea through the Gulf of Oman and the Strait of Hormuz. The Persian Gulf has a large coastal population, and is relevant economically and geopolitically, and so it is important to understand sea-level changes in the region. We use satellite observations from the Gravity Recovery and Climate Experiment (<strong>GRACE</strong>) and satellite altimetry to study intraseasonal sea level variation over the Persian Gulf during 2002-2015. We interrogate the spatial scales and forcing functions of the variation and its relation to large-scale circulation and climate over the Indian Ocean. Empirical orthogonal function analysis applied to sea level data from satellite altimetry reveals that the intraseasonal sea level variation in the Persian Gulf is dominated by a basin-wide, single-signed mode of fluctuation. Maximum covariance analysis applied to altimetry and GRACE satellite retrievals shows that these basin-wide intraseasonal sea level fluctuations are largely barotropic in nature and coupled to variations in ocean bottom pressure. To interpret the results, we develop a simple linear barotropic theory based on volume and momentum conservation. The theory describes Persian Gulf sea level in terms of freshwater flux over the region, wind stress along the Strait of Hormuz, and sea level in the Gulf of Oman. To test this theory, we perform a complex multiple linear regression using these regional freshwater flux, wind stress, and sea level as inputs, and Persian Gulf sea level as output. The regression model explains ~70% of the intraseasonal Persian Gulf sea level variance. The magnitudes and phases of the coefficients determined from the regression model are consistent with expectations from the simple theory. The Gulf of Oman sea level boundary condition shows significant lagged correlation with intraseasonal sea level upstream along the Indian Subcontinent, Maritime Continent, and equatorial Indian Ocean. This hints at a large-scale circulation and climate influence on intraseasonal sea level variation of the Persian Gulf mediated by waves propagating along equatorial and coastal waveguides. This study highlights the value of GRACE retrievals of ocean bottom pressure for understanding sea level in an understudied semi-enclosed marginal sea.</p>

scholarly journals Late Quaternary sea-level changes of the Persian Gulf

2015 ◽  
Vol 84 (1) ◽  
pp. 69-81 ◽  
Author(s):  
Stephen W. Lokier ◽  
Mark D. Bateman ◽  
Nigel R. Larkin ◽  
Philip Rye ◽  
John R. Stewart
Keyword(s):  
Sea Level ◽  
Persian Gulf ◽  
Late Holocene ◽  
Late Quaternary ◽  
Sea Level Changes ◽  
Coastal System ◽  
Shallow Subtidal ◽  
Forced Regression ◽  
The Persian Gulf ◽  
Holocene Sea Level

Late Quaternary reflooding of the Persian Gulf climaxed with the mid-Holocene highstand previously variously dated between 6 and 3.4 ka. Examination of the stratigraphic and paleoenvironmental context of a mid-Holocene whale beaching allows us to accurately constrain the timing of the transgressive, highstand and regressive phases of the mid- to late Holocene sea-level highstand in the Persian Gulf. Mid-Holocene transgression of the Gulf surpassed today's sea level by 7100–6890 cal yr BP, attaining a highstand of > 1 m above current sea level shortly after 5290–4570 cal yr BP before falling back to current levels by 1440–1170 cal yr BP. The cetacean beached into an intertidal hardground pond during the transgressive phase (5300–4960 cal yr BP) with continued transgression interring the skeleton in shallow-subtidal sediments. Subsequent relative sea-level fall produced a forced regression with consequent progradation of the coastal system. These new ages refine previously reported timings for the mid- to late Holocene sea-level highstand published for other regions. By so doing, they allow us to constrain the timing of this correlatable global eustatic event more accurately.

Sign in / Sign up

Export Citation Format

Share Document