scholarly journals A Method to Estimate Three-Dimensional Thermal Structure from Satellite Altimetry Data

2009 ◽  
Vol 26 (12) ◽  
pp. 2655-2664 ◽  
Author(s):  
Akiko Takano ◽  
Hidekatsu Yamazaki ◽  
Takeyoshi Nagai ◽  
Osamu Honda
Keyword(s):  
Satellite Altimetry ◽  
Thermal Structure ◽  
Three Dimensional ◽  
Empirical Method ◽  
Altimetry Data ◽  
Spatiotemporal Mapping ◽  
Strong Linear Correlation ◽  
Globally Distributed ◽  
Satellite Altimetry Data

Abstract A new empirical method to estimate mesoscale three-dimensional oceanic thermal structures from near-real-time satellite altimetry data is presented. The method uses a two-layer model with a novel set of empirical parameters for stratification. Empirical parameters, which are calculated from altimetry data and in situ temperature and salinity profiles obtained from globally distributed Argo floats, allowed for significant increases in the spatiotemporal mapping of mesoscale temperature distributions. The accuracy of the method was validated by comparing the estimated isothermal depths with in situ temperature data. Three case studies in different regions and seasons showed excellent agreement, with a strong linear correlation between the estimated and observed isothermal depths. The authors present the details of the method, discuss its limitations, and demonstrate the ecological relevance of the method for fisheries management by successfully predicting pelagic fish distributions.

scholarly journals More confounders at global and decadal scales in detecting recent sea level accelerations

2015 ◽  
Vol 5 (1) ◽  
Author(s):  
H. Bâki Iz
Keyword(s):  
Sea Level ◽  
Satellite Altimetry ◽  
Tide Gauge ◽  
Almost Periodic ◽  
Altimetry Data ◽  
Tide Gauge Data ◽  
Gauge Data ◽  
Close Range ◽  
Globally Distributed ◽  
Satellite Altimetry Data

AbstractThe residuals of 27 globally distributed long tide gauge recordswere scrutinized after removing the globally compounding effect of the periodic lunar node tides and almost periodic solar radiation’s sub and superharmonics from the tide gauge data. The spectral analysis of the residuals revealed additional unmodeled periodicities at decadal scales, 19 of which are within the close range of 12–14 years, at 27 tide gauge stations. The amplitudes of the periodicitieswere subsequently estimated for the spectrally detected periods and they were found to be statistically significant (p «0.05) for 18 out of 27 globally distributed tide gauge stations. It was shown that the estimated amplitudes at different localities may have biased the outcome of all the previous studies based on tide gauge or satellite altimetry data that did not account for these periodicities, within the range −0.5 – 0.5 mm/yr., acting as another confounder in detecting 21st century sea level rise.

scholarly journals Comparing satellite altimetry and tide gauges observations in the Mediterranean Sea within the framework of singular spectrum analysis

MAUSAM ◽  
2021 ◽  
Vol 71 (2) ◽  
pp. 187-198
Author(s):  
HADDAD MAHDI ◽  
TAIBI HEBIB ◽  
MOKRANE MOUSTAFA ◽  
HAMMOUMI HOUSSEYN
Keyword(s):  
Sea Level ◽  
Spectrum Analysis ◽  
Satellite Altimetry ◽  
Tide Gauge ◽  
Singular Spectrum Analysis ◽  
Altimetry Data ◽  
Tide Gauges ◽  
The Mediterranean ◽  
Satellite Altimetry Data

By considering time series from satellite altimetry and tide gauges that extend back to 1993, Singular Spectrum Analysis (SSA) is applied to investigate and compare the non linear trends of the sea level along the Mediterranean coasts. The major issue of this comparison is to show if the satellite altimetry data could be representative of the local sea level as observed by tide gauges.   The results indicate that the local trends estimated from an in-situ tide gauge and satellite altimetry data show nearly identical positive rates over the period from 1993 to 2017. The differences between the estimated rates of sea level change from in-situ tide gauge and satellite measurements vary, in absolute value, from 0.18 to 4.29 mm/year with an average of 1.55 mm/year.   This result is sufficient to admit, if necessary, on the one hand, the complementarily of the two measurement techniques (satellite altimetry and tide gauges) and, on the other hand, the rise in sea level near the Mediterranean coastal areas.

Eddy properties in the Pacific sector of the Southern Ocean from satellite altimetry data

2016 ◽  
Vol 35 (11) ◽  
pp. 28-34 ◽  
Author(s):  
Yongliang Duan ◽  
Hongwei Liu ◽  
Weidong Yu ◽  
Yijun Hou
Keyword(s):  
Southern Ocean ◽  
Satellite Altimetry ◽  
Altimetry Data ◽  
The Pacific ◽  
Satellite Altimetry Data

Kuroshio variations in the upstream region as seen by HF radar and satellite altimetry data

2008 ◽  
Vol 29 (21) ◽  
pp. 6417-6426 ◽  
Author(s):  
K. Ichikawa ◽  
R. Tokeshi ◽  
M. Kashima ◽  
K. Sato ◽  
T. Matsuoka ◽  
...  
Keyword(s):  
Satellite Altimetry ◽  
Hf Radar ◽  
Upstream Region ◽  
Altimetry Data ◽  
Satellite Altimetry Data

scholarly journals Evaluation of Marine Gravity Anomaly Calculation Accuracy by Multi-Source Satellite Altimetry Data

2021 ◽  
Vol 9 ◽  
Author(s):  
Shanwei Liu ◽  
Yinlong Li ◽  
Qinting Sun ◽  
Jianhua Wan ◽  
Yue Jiao ◽  
...  
Keyword(s):  
Root Mean Square Error ◽  
Gravity Anomaly ◽  
Mean Square Error ◽  
Spatial Resolution ◽  
Satellite Altimetry ◽  
Gravity Anomalies ◽  
Mean Square ◽  
Altimetry Data ◽  
Marine Gravity ◽  
Satellite Altimetry Data

The purpose of this paper is to analyze the influence of satellite altimetry data accuracy on the marine gravity anomaly accuracy. The data of 12 altimetry satellites in the research area (5°N–23°N, 105°E–118°E) were selected. These data were classified into three groups: A, B, and C, according to the track density, the accuracy of the altimetry satellites, and the differences of self-crossover. Group A contains CryoSat-2, group B includes Geosat, ERS-1, ERS-2, and Envisat, and group C comprises T/P, Jason-1/2/3, HY-2A, SARAL, and Sentinel-3A. In Experiment I, the 5′×5′ marine gravity anomalies were obtained based on the data of groups A, B, and C, respectively. Compared with the shipborne gravity data, the root mean square error (RMSE) of groups A, B, and C was 4.59 mGal, 4.61 mGal, and 4.51 mGal, respectively. The results show that high-precision satellite altimetry data can improve the calculation accuracy of gravity anomaly, and the single satellite CryoSat-2 enables achieving the same effect of multi-satellite joint processing. In Experiment II, the 2′×2′ marine gravity anomalies were acquired based on the data of groups A, A + B, and A + C, respectively. The root mean square error of the above three groups was, respectively, 4.29 mGal, 4.30 mGal, and 4.21 mGal, and the outcomes show that when the spatial resolution is satisfied, adding redundant low-precision altimetry data will add pressure to the calculation of marine gravity anomalies and will not improve the accuracy. An effective combination of multi-satellite data can improve the accuracy and spatial resolution of the marine gravity anomaly inversion.

Sign in / Sign up

Export Citation Format

Share Document