The Time Series Spectral Analysis of Satellite Altimetry and Coastal Tide Gauges and Tide Modeling in the Coast of Caspian Sea

Pirooznia, Mahmoud; Emadi, S. R.; Alamdari, M. Najafi

doi:10.4236/ojms.2016.62021

Cited by 17 publications

(7 citation statements)

References 3 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…To address this issue, a waveform retracking method known as the adaptive leading edge sub-waveform (ALES) is applied to correct the range observations [16]. Additionally, inherent uncertainties exist in satellite altimetry measurements, including errors introduced by geophysical and environmental factors, which are typically addressed through global or local modeling techniques [23,24]. Moreover, the systematic errors, such as radial error [24], present in the satellite altimeter datasets require calibration, which is considered as described in [25].…”

Section: Data Descriptionmentioning

confidence: 99%

Integrating Hydrography Observations and Geodetic Data for Enhanced Dynamic Topography Estimation

Pirooznia,

Voosoghi,

Poreh

et al. 2024

Remote Sensing

Self Cite

View full text Add to dashboard Cite

Dynamic topography (DT) refers to the time-varying component of the sea surface height influenced by factors like ocean currents, temperature, and salinity gradients. Accurate estimation of DT is crucial for comprehending oceanic circulation patterns and their impact on climate. This study introduces two approaches to estimating DT: (1) utilizing satellite altimetry to directly observe sea surface height and (2) considering the steric and non-steric components of sea level anomalies. The steric term is calculated using salinity and temperature data obtained from local buoy data, Argo observations, and the World Ocean Atlas model. The non-steric term is calculated using GRACE Satellite gravimetry data. To estimate the assimilated DT, four methods are utilized, including variance component estimation (VCE), Bayesian theory, Kalman filter, and 3D variational (3DVAR). These methods assimilate the two aforementioned schemes. The validity of the estimated DT is assessed by comparing the calculated sea surface current, derived from the obtained DT, with observations from local current meter stations. The results indicate that the VCE method outperforms other methods in determining the final DT. Furthermore, incorporating the steric and non-steric terms of sea level in determining DT in coastal areas enhances the accuracy of estimating sea surface currents.

show abstract

Section: Data Descriptionmentioning

confidence: 99%

Integrating Hydrography Observations and Geodetic Data for Enhanced Dynamic Topography Estimation

Pirooznia,

Voosoghi,

Poreh

et al. 2024

Remote Sensing

Self Cite

View full text Add to dashboard Cite

show abstract

“…The range observation is contaminated by some source of errors which must be corrected via global or local modeling and can be summarized as follows: wet troposphere correction, dry troposphere correction, ionosphere correction, electromagnetic bias correction, ocean tide correction, inverse barometer correction, pole tide correction and center of gravity movement. They are better known as "geophysical corrections" [Benada, 1997;Pirooznia et al, 2016a;Soltanpour et al 2017]. Also the re-tracking correction is used to correct range observation.…”

Section: Re-tracking Of Sa Observationsmentioning

confidence: 99%

Point wise Determination of Vertical Deformation at southern Coastal Areas of Caspian Sea by Combination of Satellite Altimetry and Tide Gauge Observations

Pirooznia

Naeeni

Yousefzadeh

2020

Annals of Geophysics

View full text Add to dashboard Cite

In this paper, a combination of satellite altimetry (SA) and tide-gauge (TG) observations is used to determine the pattern of vertical deformation at southern coasts of Caspian Sea. Satellite altimetry measures the variations of sea water surface with a respect to a reference ellipsoid, while tide gauge data gives the sea level relative to a particular ground station; consequently, the difference between these two observations will give the vertical motion at the ground station. However, altimeter satellites still have problems at shallow waters or coastal areas which leads to inaccurate and corrupted sea surface height at tide gauge stations. To minimize this imprecision, two strategies are applied for the selection of the suitable SA points near the TG stations. The First one is to choose those close passes to the TG stations, provided that the SA data is not corrupted (range observation is available). The second strategy is to extrapolate the SA points at TG stations using Spatio- Temporal Kriging method. In both point of views, use is made of re-tracking methods to improve the ranges of SA observations near the coast. Amplitudes of tidal components are removed from both SA and TG observations to derive the residual tide free signals. Afterward, a linear trend is fitted to the residual signals in the sense of least square; the difference between these two, supplies the vertical deformation of the ground station. The results illustrate that the average vertical crustal motion at Anzali, Noshahr and Neka are -1.387, -1.903 and -3.14 mm/year, respectively.

show abstract

“…Pirooznia et al [7] used the least-squares spectral (LSS) analysis method to examine sea-level time series of altimetry data (TOPEX/Poseidon, Jason-1, and Jason-2) and three tide gauges located in the Caspian Sea. The spectral analysis revealed that solar annual (Sa) signals play a dominant role in sea-level variation of the Caspian Sea.…”

Section: Introductionmentioning

confidence: 99%

Spectral Analysis of Satellite Altimeter and Tide Gauge Data around the Northern Australian Coast

Gharineiat

Deng

2020

Remote Sensing

View full text Add to dashboard Cite

The north of Australia is known for its complex tidal system, where the highest astronomical tides (HATs) reach 12 m. This paper investigates the tidal behaviour in this region by developing spectral climatology for tide gauge and altimetry data. Power spectral density analysis is applied to detect the magnitude of ocean tides in 20 years of sea-level data from multimission satellite altimeters and tide gauges. The spectra of altimetry sea level anomaly (SLA) time series have their strongest peaks centred at approximately 2.11, 5.88, and 7.99 cycles per year (cpy), corresponding to the diurnal and semidiurnal tidal constituents K1, M2, and O1, respectively. Closer to the coastline, the spectra peak at high-frequency overtide and shallow-water constituents such as M4, MK4, and MK3. There have been many large, high-frequency spectral peaks near the coastline, indicating the difficulty of predicting tidal signals by coastal altimetry. Similar to altimetry observations, there are dominant semidiurnal and diurnal tidal peaks in tide gauge SLA time series accompanying a number of overtides. The semidiurnal and diurnal peaks are mostly higher on the northwest coast of Australia compared with the north and northeast coast. The results from both altimetry and tide gauges indicate that tidal range increases with increasing continental shelf.

show abstract

The Time Series Spectral Analysis of Satellite Altimetry and Coastal Tide Gauges and Tide Modeling in the Coast of Caspian Sea

Cited by 17 publications

References 3 publications

Integrating Hydrography Observations and Geodetic Data for Enhanced Dynamic Topography Estimation

Integrating Hydrography Observations and Geodetic Data for Enhanced Dynamic Topography Estimation

Point wise Determination of Vertical Deformation at southern Coastal Areas of Caspian Sea by Combination of Satellite Altimetry and Tide Gauge Observations

Spectral Analysis of Satellite Altimeter and Tide Gauge Data around the Northern Australian Coast

Contact Info

Product

Resources

About