scholarly journals Pacific Decadal Oscillation and Sea Level Variability in the Bohai, Yellow, and East China Seas

2008 ◽  
Vol 38 (12) ◽  
pp. 2772-2783 ◽  
Author(s):  
Guoqi Han ◽  
Weigen Huang
Keyword(s):  
Sea Level ◽  
Pacific Decadal Oscillation ◽  
Decadal Variability ◽  
Tide Gauge ◽  
East China ◽  
Tide Gauge Data ◽  
Sea Level Variability ◽  
Steric Height ◽  
Gauge Data ◽  
Ocean Topography

Abstract Sea level variability off East China has been investigated based primarily on 10 years of Ocean Topography Experiment (TOPEX)/Poseidon altimetry data. The altimetric annual harmonic has a magnitude of 10 to 30 cm in amplitude and is highest in summer, agreeing well with independent tide-gauge data. After the inverse barometer effect is removed, the annual sea level cycle can be approximately accounted for by the steric height variation. Significant interannual sea level change was also observed from altimetry and tide-gauge data, with a range of ∼10 cm. The interannual and longer-term sea level variability in the altimetric data are negatively correlated (significant at the 95% confidence level) with the Pacific decadal oscillation (PDO), attributed in part to steric height change. The altimetric sea level rise rate is 0.64 cm yr−1 for the period from 1992 to 2002, consistent with the tide-gauge rate of 0.6 cm yr−1. These values are much larger than the rate of 0.24 cm yr−1 observed at the same tide gauges but for the period from 1980 to 2002, implying the sensitivity to the length of data as a result of the decadal variability. The potential role of the PDO in the interannual and longer-term sea level variability is discussed in terms of regional manifestations such as the ocean temperature and salinity and the Kuroshio transport.

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 Modeling regional sea level rise using local tide gauge data

2012 ◽  
Vol 2 (3) ◽  
pp. 188-199 ◽  
Author(s):  
H. Bâki Iz ◽  
L. Berry ◽  
M. Koch
Keyword(s):  
Sea Level ◽  
Tide Gauge ◽  
Reference Level ◽  
Tide Gauge Data ◽  
Mean Sea Level ◽  
Proposed Model ◽  
Gauge Data ◽  
Local Reference ◽  
Order Of Magnitude ◽  
Serial Correlations

AbstractCurrently regional mean sea level trends and variations are inferred from the analysis of several individual local tide gauge data that spanonly a long period of time at a given region. In this study, we propose using a model to merge various tide gauge data, regardless of theirtime span, in a single solution, to estimate parameters representative of regional mean sea level trends. The proposed model can accountfor the geographical correlations among the local tide gauge stations as well as serial correlations, if needed, for individual stations’ data.Such a vigorous regional solution enables statistically optimal uncertainties for estimated and projected trends. The proposed formulationalso unifies all the local reference levels by modeling their offsets from a predefined station’s reference level. To test its effectiveness, theproposed model was used to investigate the regional mean sea level variations for the coastal areas of the Florida Panhandle using 26 localtide gauge stations that span approximately 830 years of monthly averages from the Permanent Service for Mean Sea Level repository. Thenew estimate for the regional trend is 2.14 mm/yr with a ±0.03 mm/yr standard error, which is an order of magnitude improvement overthe most recent mean sea level trend estimates and projections for the Florida region obtained from simple averages of local solutions.

Review and Assessment of gap-filling methods from tide-gauges: Maxima missing at the Esbjerg, Denmark station, before 1910.

2020 ◽  
Author(s):  
Peter Thejll
Keyword(s):  
Sea Level ◽  
Tide Gauge ◽  
Model Fit ◽  
Tide Gauges ◽  
Harmonic Model ◽  
Gap Filling ◽  
Tide Gauge Data ◽  
Tide Gauge Record ◽  
Long Baseline ◽  
Gauge Data

<p>Information on extremes of the sea-level is obtained from tide-gauge<br>records.  Such records may have gaps.</p><p>Estimates of potential changes in the size and/or frequency of sea-level<br>extremes are hampered by long gaps, or when just the high extremes are<br>missing due, e.g. to equipment failure.</p><p>Methods used for filling such gaps can be based on having multiple<br>records from gauges near each other; but what to do if there is<br>only one record? This problem can typically occur when old tide-gauge<br>records are used -- the use of multiple recorders at the same place is<br>more wide-spread today. However, especially older and therefore longer<br>records hold the key to obtaining long-baseline insights into the temporal<br>evolution of extreme tides and thus impacts of e.g. climate change.</p><p>In this work, we review and assess methods for gap filling. We asses using<br>the 'known truth' method, i.e. by applying realistic gaps to complete<br>gauge records and reconstructing and then comparing errors calculated as<br>the diffrence between modelled and actual values.  We compare a simple<br>harmonic model fit method to various spline methods as well as Neural<br>network and deep learning approches.  We also test a hybrid method<br>which uses not just tide-gauge data but also air pressure readings<br>from a meteorological station near the tide-gauge.</p><p>We then attempt to fill in the missing maxima of the Esbjerg, Denmark<br>hourly tide-gauge record since 1889. Particularly, before 1910 the maxima<br>above 300 cm are missing (Bijl, et al., 1999), and we try to fill these in.</p>

Sign in / Sign up

Export Citation Format

Share Document