Ocean Tides Research Articles

Combination of Tsoft and ET34-ANA-V80 software for the preprocessing and analysis of tide gauge data in French Polynesia

Since 2008 a network of five sea-level monitoring stations was progressively installed in French Polynesia. The stations are autonomous and data, collected at a sampling rate of 1 or 2 min, are not only recorded locally, but also transferred in real time by a radio-link to the NOAA through the GOES satellite. The new ET34-ANA-V80 version of ETERNA, initially developed for Earth Tides analysis, is now able to analyze ocean tides records. Through a two-step validation scheme, we took advantage of the flexibility of this new version, operated in conjunction with the preprocessing facilities of the Tsoft software, to recover corrected data series able to model sea-level variations after elimination of the ocean tides signal. We performed the tidal analysis of the tide gauge data with the highest possible selectivity (optimal wave grouping) and a maximum of additional terms (shallow water constituents). Our goal was to provide corrected data series and modelled ocean tides signal to compute tide-free sea-level variations as well as tidal prediction models with centimeter precision. We also present in this study the characteristics of the ocean tides in French Polynesia and preliminary results concerning the non-tidal variations of the sea level concerning the tide gauge setting.

Performance and near-wake characteristics of a bidirectional horizontal-axis tidal turbine

Horizontal-axis tidal turbines (HATTs) have the potential to produce considerable amount of clean renewable energy from ocean tides. To reduce costs and improve reliability, a full-scale bidirectional HATT (BHATT) with a centrosymmetric hydrofoil was designed to operate in two opposite flow directions. To better understand the performance and the near-wake characteristics of the BHATT, a three-dimensional (3D) numerical model with a k-ω SST model and a sliding mesh method was applied. The numerical framework was validated using two different experiments, and the mesh convergence was tested. The result shows that the BHATT can achieve a power coefficient of 43.5% at design tip speed ratio (TSR), and cause a remarkable circumferential flow in the near-wake from it. In addition, the presence of a support structure causes a decrease and a fluctuation in both power and thrust coefficient, especially when the rotor is downstream from the support structure. Similarly, a misalignment also leads to a decrease in both power and thrust coefficient. However, it causes almost no fluctuation. Finally, the influence of different support structures on the performance of the BHATT in different misalignment cases was studied.

On the Link Between Global Volcanic Activity and Global Mean Sea Level

Studying a large number of volcanic eruptions is a way to decipher general characteristics related to volcano dynamics but also on external forcing influencing it, such as solid Earth and ocean tides. Many studies have tackled this tidal influence on the onset of volcanic eruptions and more generally, on volcanic activity. However, the interplay between this quasi-permanent forcing and volcanic systems is still poorly understood. With the present study, we propose to consider a global viewpoint to address this interaction. We analyzed the number of monthly volcanic eruptions and the global mean sea level between 1880 and 2009 using the Singular Spectrum Analysis time-series analysis technique to evaluate the existence of common periodicities. We found multi-decadal components of similar periodicities present in both time-series which we link to those already recognized in the polar motion. Its multi-decadal variations result in a mass reorganization in the oceans whose associated stress changes may impact processes generating volcanic eruptions worldwide. Our results show the influence of global processes on volcanic activity and open many questions to further investigate these multi-scale interactions.

Tidal Modulation of a Lateral Shear Margin: Priestley Glacier, Antarctica

We use high resolution, ground-based observations of ice displacement to investigate ice deformation across the floating left-lateral shear margin of Priestley Glacier, Terra Nova Bay, Antarctica. Bare ice conditions allow us to fix survey marks directly to the glacier surface. A combination of continuous positioning of a local reference mark, and repeat positioning of a network of 33 stakes installed across a 2 km width of the shear margin are used to quantify shear strain rates and the ice response to tidal forcing over an 18-day period. Along-flow velocity observed at a continuous Global Navigation Satellite Systems (GNSS) station within the network varies by up to ∼30% of the mean speed (±28 m a−1) over diurnal tidal cycles, with faster flow during the falling tide and slower flow during the rising tide. Long-term deformation in the margin approximates simple shear with a small component of flow-parallel shortening. At shorter timescales, precise optical techniques allow high-resolution observations of across-flow bending in response to the ocean tide, including across-flow strains on the order of 10–5. An elastodynamic model informed by the field observations is used to simulate the across-flow motion and deformation. Flexure is concentrated in the shear margin, such that a non-homogeneous elastic modulus is implied to best account for the combined observations. The combined pattern of ice displacement and ice strain also depends on the extent of coupling between the ice and valley sidewall. These conclusions suggest that investigations of elastic properties made using vertical ice motion, but neglecting horizontal displacement and surface strain, will lead to incorrect conclusions about the elastic properties of ice and potentially over-simplified assumptions about the sidewall boundary condition.

Performance of a bidirectional horizontal-axis tidal turbine with passive flow control devices

Horizontal-axis tidal turbines (HATTs) have the acknowledged potential to extract a large amount of green renewable energy from ocean tides. Among these, bidirectional HATTs (BHATTs) with centrosymmetric hydrofoils have advantages in terms of reliability and maintenance cost. To improve the performance of BHATTs, this paper investigates the influence of different passive flow control devices (PFCDs), such as wing fences, winglets, and squealers, on the performance of the BHATT. To the end, a three-dimensional (3D) numerical model with a k-ω SST model and a sliding mesh method was applied to simulate a 18 m diameter BHATT. The numerical framework was validated using two experiments. The mesh convergence was tested. The results show that the wing fences can effectively suppress the spanwise flow above the suction surface of blades, although they cannot improve the BHATT performance. To inhibit the wingtip vortices and enhance the torque of the rotor, a series of centrosymmetric winglets are designed and optimized. The optimal BHATT can produce up to 2.3% more energy at design tip speed ratio (TSR).

Enhanced turbulent mixing in mesoscale eddies near the critical latitude of the M2 internal tides

Mesoscale eddies can elevate turbulent mixing, but the mechanisms have not been fully understood. Based on a field experiment in two mesoscale eddies near the critical latitude of the M2 internal tides in the northwestern Pacific Ocean, enhanced turbulent mixing was found both in and below the mixed layer. Microstructure observations indicate that enhanced turbulent mixing mainly appeared outside the eddy center in the mixed layer (approximately 117 m), which was speculated to be related to geostrophic current shear. By analyzing the CTD and Argo measurements through a fine-scale parameterization method, enhanced turbulent mixing was found to be concentrated at the southern flank of the anticyclonic eddy below 300 m, which showed little correlation with topographic roughness and local winds. Based on a ray-tracing model, the wind-generated near-inertial waves at higher latitudes were also excluded as the cause of the enhanced turbulent mixing. The enhanced turbulent mixing below 300 m was generally consistent with the features of subthermocline eddies and eddy-modulated parametric subharmonic instability (PSI) of the M2 internal tides. However, due to the limitation of observations, the eddy-modulated PSI mechanism was not fully validated.

Dissipation and Bathymetric Sensitivities in an Unstructured Mesh Global Tidal Model

AbstractThe mechanisms and geographic distribution of global tidal dissipation in barotropic tidal models are examined using a high resolution unstructured mesh finite element model. Mesh resolution varies between 2 and 25 km and is especially focused on inner shelves and steep bathymetric gradients. Tidal response sensitivities to bathymetric changes are examined to put into context response sensitivities to frictional processes. We confirm that the Ronne Ice Shelf dramatically affects Atlantic tides but also find that bathymetry in the Hudson Bay system is a critical control. We follow a sequential frictional parameter optimization process and use TPXO9 data‐assimilated tidal elevations as a reference solution. From simulated velocities and depths, dissipation within the global model is estimated and allows us to pinpoint dissipation at high resolution. Boundary layer dissipation is extremely focused with 1.4% of the ocean accounting for 90% of the total. Internal tide friction is much more distributed with 16.7% of the ocean accounting for 90% of the total. Often highly regional dissipation can impact basin‐scale and even ocean wide tides. Optimized boundary layer friction parameters correlate very well with the physical characteristics of the locality with high friction factors associated with energetic tidal regions, deep ocean island chains, and ice covered areas. Global complex M2 tide errors are 1.94 cm in deep waters. Total global boundary layer and internal tide dissipation are estimated, respectively, at 1.83 and 1.49 TW. This continues the trend in the literature toward attributing more dissipation to internal tides.

Modeling gravimetric signatures of third-degree ocean tides and their detection in superconducting gravimeter records

We employ the barotropic, data-unconstrained ocean tide model TiME to derive an atlas for degree-3 tidal constituents including monthly to terdiurnal tidal species. The model is optimized with respect to the tide gauge data set TICON-td that is extended to include the respective tidal constituents of diurnal and higher frequencies. The tide gauge validation shows a root-mean-square (RMS) deviation of 0.9–1.3 mm for the individual species. We further model the load tide-induced gravimetric signals by two means (1) a global load Love number approach and (2) evaluating Greens-integrals at 16 selected locations of superconducting gravimeters. The RMS deviation between the amplitudes derived using both methods is below 0.5 nGal (1 nGal = 0.01 frac{text {nm}}{text {s}^2}) when excluding near-coastal gravimeters. Utilizing ETERNA-x, a recently upgraded and reworked tidal analysis software, we additionally derive degree-3 gravimetric tidal constituents for these stations, based on a hypothesis-free wave grouping approach. We demonstrate that this analysis is feasible, yielding amplitude predictions of only a few 10 nGal, and that it agrees with the modeled constituents on a level of 63–80% of the mean signal amplitude. Larger deviations are only found for lowest amplitude signals, near-coastal stations, or shorter and noisier data sets.

On the characterization of tidal ocean-dynamo signals in coastal magnetic observatories

Periodic tidal ocean currents induce electric currents and, therefore, magnetic field signals that are observable using spaceborne and ground-based observation techniques. In theory, the signals can be used to monitor oceanic temperature and salinity variations. Tidal magnetic field amplitudes and phases have been extracted from magnetometer measurements in the past. However, due to uncertainties caused by a plentitude of influencing factors, the shape and temporal variation of these signals are only known to a limited extent. This study uses past extraction methods to characterize seasonal variations and long-term trends in the ten year magnetometer time series of three coastal island observatories. First, we assess data processing procedures used to prepare ground-based magnetometer observations for tidal ocean dynamo signal extraction to demonstrate that existing approaches, i.e., subtraction of core field models or first-order differencing, are unable to reliably remove low-frequency contributions. We hence propose low-frequency filtering using smoothing splines and demonstrate the advantages over the existing approaches. Second, we determine signal and side peak magnitudes of the M2 tide induced magnetic field signal by spectral analysis of the processed data. We find evidence for seasonal magnetic field signal variations of up to 25% from the annual mean. Third, to characterize the long-term behavior of tidal ocean dynamo signal amplitudes and phases, we apply different signal extraction techniques to identify tidal ocean-dynamo signal amplitudes and phases in sub-series of the ten-year time series with incrementally increasing lengths. The analyses support three main findings: (1) trends cause signal amplitude changes of up to approx 1~nT and phase changes are in the order of {mathcal {O}}(10^{circ }) within the observation period; (2) at least four years of data are needed to obtain reliable amplitude and phase values with the extraction methods used and (3) signal phases are a less dependent on the chosen extraction method than signal amplitudes.Graphical

Extaction of Maximum Power from PV and Wind Energy Sources Using Predictive Control System in Microgrids

The impact of global warming and changing climatic conditions due to over exploitation of fossil fuels, emission of high carbon levels, and increased demand for energy have necessitated the application of renewable energy sources. Load demand is addressed by the default design of microgrids, with minimal changes in their architecture to adhere the introduction of electricity generated from different renewable sources. Renewable energy sources are generated from photovoltaic cells (solar), wind, and ocean tides, and India has been extending the deployment of solar and wind energy generation centers. The proposed system concentrates over the algorithms for Maximum Power Point tracking schemes to analyze how the renewable sources of energy are used to yield the maximum power. The same energy is stored in a battery storage and hence used whenever necessary. A definite set of control measures are defined within the Model Predictive Controlling mechanism, enabled to control the inverters, further defined to address the requirements of consistent AC load voltages. The inverters are controlled through a novel design of DC-DC Buck Boost Converter of battery and Model Predictive Controller is facilitated with DC-AC inverters. The controllers are modelled with MATLAB/SIMULINK with power droop controllers within the microgrid system. Proposed system was evaluated through simulations and from the investigative results, predictive controlling scheme has outperformed the other control strategies, while handling the fluctuating PV and wind energy sources.

A Study on Developing Marine Space Planning as a Transboundary Marine Governance Mechanism—The Case of Illegal Sand Mining

Kinmen’s coastline has gradually retreated in recently years, which has resulted in changes in coastal landforms. Research shows that possible factors are ocean currents, monsoons, tides, coastal development, and other anthropic factors such as unauthorized sand mining in the sea area between Kinmen and Xiamen. This study utilized a literature analysis, data collection, in-depth interviews, a field study, and expert opinion in order to establish a managing mechanism for marine spatial planning (MSP) for the sea area between Kinmen and Xiamen. To achieve the goal, the study analyzed law enforcement capacity in the sea area between Kinmen and Xiamen and explored how Taiwan and China can shelve sovereignty disputes and make a workable action plan for cooperating in maritime law enforcement based on a pragmatic and reciprocal principle. Finally, the study proposed to build an MSP-based managing mechanism that can be jointly operated by Kinmen, Xiamen, Zhangzhou, and Quanzhou, because they belong to the same sea area. The results of this study can provide information on marine issues encountered in the governance of countries surrounding seas, such as the marine pollution problems of the countries surrounding the Baltic Sea and Mediterranean Sea.

Test of ocean tide loading models on the basis of strain data measured at the Vyhne Tidal Station, Slovakia

Tidal strain time series recorded at the Vyhne Tidal Station are used to test thirteen different ocean tide loading models. Ten models have been calculated using SPOTL: EOT11a, HAMTIDE11a, OSU.TPXO72atlas, OSU.TPXO72, TPX070, DTU10, CSR4.0, FES2004, FES95.2.1, SCHW1 and three other models were chosen from the Free Ocean Tide Loading Provider (FOTLP) created by Scherneck and Bos: FES2012, FES2014b, GOT00.2. Hourly sampled strain data, corrected for temperature, were subjected to correction for ocean tide loading. The test of models was focused on the diurnal and semi-diurnal tidal harmonic constituents O1, P1, K1 and M2. A negligible difference between the individual global ocean tide loading models was only found mainly due to using different Earth models and Green functions. The amplitude factors for O1, P1, K1 and M2 derived from the measurements are 1.019, 1.226, 0.842 and 1.131, respectively. The average amplitude factors for these tidal components were obtained after ocean load correction using SPOTL routines: 1.121, 1.332, 0.916, 1.283, and in the case of the three models using FOTLP: 1.046, 1.486, 1.067, 1.317. The corrected amplitude factor became closer to the theoretical value only for K1.

Advances and Accuracy Assessment of Ocean Tide Models in the Antarctic Ocean

Ocean tides in polar regions play an important role in the study of sea ice dynamics and floating ice shelves. The accuracy of existing ocean tide models in shallow waters and polar seas is much lower than that in open deep oceans. This study summarized the advances of state-of-the-art global tide models in the Antarctic Ocean, the construction of tide models around Circum-Antarctica, and five typical regions: Antarctic Peninsula, Ross Sea, Filchner–Ronne Ice Shelf (FRIS), Weddell Sea, and Amery Ice Shelf (AIS). The accuracy of FES 2014, TPXO9, EOT20, CATS 2008, and regional tide models in the Antarctic Ocean and typical areas was evaluated using tidal records and satellite altimetry data. EOT20 and ANTPEN04.01 models have higher accuracy in the Antarctic Peninsula, and the root sum square (RSS) values are 8.29 and 7.46 cm, respectively. TPXO9 has the highest accuracy in the Weddell Sea and FRIS and AIS and RSS values are 18.33 and 12.77 cm, respectively. TPXO9 and RIS_Optimal models have higher accuracy in the Ross Sea and Ross Ice Shelf (RIS), RSS values are 5.62 and 6.21 cm, respectively. The accuracy of FES 2014, TPXO9, CATS 2008, and the regional tide model in the Drake Passage, Kerguelen Islands, and Adelie–Mertz was evaluated using satellite altimetry data. The RSS values are less than 4 cm. By using the altimetry data at Sentinel-3A single-satellite crossovers in terms of the STD of the SLA, the comparison of the STDs show that FES2014 is the best.

Ocean tides can drag the atmosphere and cause tidal winds over broad continental shelves

Oceanic tides lead to some of the largest currents of the world ocean and have important implications for oceanic circulation. In the last decade, the feedback effect of surface currents on the overlying winds has been shown to strongly regulate the ocean circulation. Here we present evidence, using coupled high-resolution ocean-atmosphere simulations and in situ measurements, that ocean tides can drag the atmosphere above. The current-induced tidal winds expand across the atmospheric boundary layer, while dissipating tidal energy. They are likely present in many shelf regions of the world ocean, with an amplitude of about one-third of the underlying tidal currents, i.e., up to 1.5 ms−1. Consideration of surface tidal winds can have implications in areas ranging from climate modeling to wind farming.

Tidal energy potential in coastal Vietnam

Tidal energy is a renewable energy source produced by the rise and fall of ocean tides. Tidal energy can be exploited using a special type of generator that converts tidal energy into electricity. Tidal power generation has the potential to open up many prospects for energy field and minimize carbon dioxide emissions that cause the greenhouse effect. To evaluate the possibility of tidal power, it is necessary to have documents and data on average annual tidal amplitude, tidal regime, and main tidal waves in the study area. To calculate the tidal power potential for the east coast of Vietnam, this article applies the calculation formula of tidal power energy by Russian scientist L.B. Bernstein. The annual mean tidal amplitude and the K1, O1, and M2 wave amplitude data at nearly 2000 calculation points along the coast of Vietnam were extracted from the TPOX8-Atlas harmonic constant set. Research results showed that Vietnam has great potential for tidal energy along the Hai Phong - Quang Ninh coastal area and the southeast region with a prospective 41.6 GWh/km2/y.

Influence of Swept Blades on the Performance and Hydrodynamic Characteristics of a Bidirectional Horizontal-Axis Tidal Turbine

Horizontal-axis tidal turbines (HATTs) have an acknowledged potential to extract a considerable amount of clean renewable energy from ocean tides. Among these, bidirectional HATTs (BHATTs) with bidirectional hydrofoils are thought to have higher economy than general HATTs. To improve the BHATTs, this study systemically investigated the influence of swept blades on the performance and hydrodynamics of the BHATT. A three-dimensional (3D) numerical model based on OpenFOAM was adopted to simulate a full-scale BHATT. The numerical framework was validated using two well-known experiments, and the mesh convergence was taken into consideration. The results indicate that the forward and backward swept blades have a limited impact on the performance and hydrodynamics of the BHATT. The upstream swept blade leads to a 4.3% decrease in the load on the rotor at design tip speed ratio (TSR) with a 2.0% decrease in the power. The BHATT with a downstream swept blade can produce 3.2% more energy at TSR = 6. Moreover, the swept blades have the opposite effect on the power of the BHATT at TSR = 6 and TSR = 9.

Spatio-temporal variations of litter on Qingdao tourist beaches in China

Beaches are an integral part of coastal tourism, but they are deteriorated by the beachgoers and recreational activities due to lack of adequate beach environmental awareness and management. Litter is widely distributed in marine and coastal environment and has been considered a severe concern. In China investigations to determine the beach litter abundance and pollution level are limited. The aim of this study is to estimate spatio-temporal distribution and composition of litter on 10 well-known Qingdao tourist beaches, involving pollution level by beach quality indexes. Beach litter was collected within an area of 25 × 25 m2 in both summer (May, June and July) and winter (Nov, Dec and Jan) seasons, and was classified into eight categories. The abundance of beach litter was found higher in summer (0.13 ± 0.04 items/m2) than in winter (0.04 ± 0.01 items/m2). Overall, the percentage of plastics were higher in both summer (23.48%) and winter (24.04%) than that of other litter categories. Based on Clean Coast Index, 70% of beaches were very clean, 25% clean, and 5% moderately clean. Beach Grade Index showed that 15% beaches were very good, 5% good, 55% fair, and 25% poor. 85% beaches constituted some quantity of hazardous litter and 15% had no hazardous litter for Hazardous Items index. The findings suggest that the sources of beach litter along Qingdao beaches mainly come from the recreational and tourist activities. The substantial quantity of litter is also being transported by ocean (tides or current), which are finally deposited along beachfront. Despite regular cleaning operation along most of Qingdao beaches, suggested management practices involve mitigation measures, source reduction, change in littering behavior to improve further quality of beaches.

Accuracy Assessment of Recent Global Ocean Tide Models Using Tide Gauge Measurements from the East Sea of Korea

Lee, J.-C. and Lee, D-H., 2023. Accuracy assessment of recent global ocean tide models using tide gauge measurements from the East Sea of Korea. Journal of Coastal Research, 39(2), 354–359. Charlotte (North Carolina), ISSN 0749-0208. The continued rise in average sea level owing to climate change has intensified coastal damage worldwide. Therefore, various studies in the field of oceanography and hydrography including the development of ocean tidal prediction models are in progress. In this study, the accuracy of the recent ocean tide models using the long and short-term tide gauge measurements from seven tidal gauging stations and 10 tidal benchmarks at the coastal area in the East Sea of Korea was assessed. For this purpose, a total of five ocean tide models, DTU10, FES2014, OSU12, NAO99, and TPXO9 were used. The accuracy of the four major tidal components (M2, S2, K1, and O1) were assessed based on the same components determined from direct tide gauge measurements in east coastal area of Korea. The tide gauge measurements used in this study consisted of long-term observation data of over 1.7 years on average from seven permanent tide gauge stations and short-term observation data of about 6.6 months on average from 10 tidal benchmarks. Observation and determination of tidal components were performed by the Korea Hydrographic and Oceanographic Agency. The accuracy of each ocean tide model was assessed by comparing the amplitude of four major components with those from tide gauge measurements for each location of tide gauge. The lowest accuracy of modelled component values was detected in the M2, S2, K1, and O1 tidal components of NAO99 model. On the contrary, FES2014 was the most accurate in M2, S2 tidal components and TPXO9 was most accurate in the K1, O1 tidal components in the East Sea of Korea.

Mapping Ocean Tidal for the Coast of East Sea Area, Viet Nam, by Using the Numerical Model in Curvilinear Coordinates

Tides and their effects on coastal and estuarine water levels are among the most well-known phenomena in coastal research. This study aims to map the tidal constituent features in the near-shore East Sea area, for better understanding of the mechanisms that cause the transport of sediments in the area. Furthermore, the study also points to the potential of tidal energy in the area, clean energy that needs to be studied for exploitation. The authors applied the hydraulic model in the curvilinear coordinates to calculate for 4 main tidal constituents in the near-shore, namely K1, O1, M2, and S2 in the East Sea area, Vietnam. The hydraulic model with two-dimensional orthogonal curvilinear grid has the advantage of increasing the accuracy in the results at the domain boundary, with the applying potential in future small-scale studies in the region. According to this method, the simulation results in areas with complex terrain are better because the velocity field is calculated on a curved grid built by shorelines). The calibration and validation of this model are based on water level data at hydrological stations along the Vietnamese coastline. The result of this model is used to map the harmonic constants and tidal ellipse for four tidal constituents; these help to gain information about the tidal deposition in the East Sea, Viet Nam. The coastal area of Vietnam has potential tidal energy; the largest energy is the tidal constituent O1, followed by the tidal constituents K1, M2, and S2. Tidal ellipses of the residual tidal constituent K1 and O1 are large in the Gulf of Tonkin and the Gulf of Thailand. Meanwhile, residual tidal constituent M2 and S2 are large in the southeast of Vietnam coastal. These results are the primary data for future research in the area.

Determination of Long-Term (1993–2019) Sea Level Rise Trends Around the Korean Peninsula Using Ocean Tide-Corrected, Multi-Mission Satellite Altimetry Data

It is vital to improve estimations of long-term trends in global and regional sea level rise to help mitigate and adapt to climate change. Satellite altimetry data have been widely used for this purpose; however, data collected in regions with strong tidalmotions often suffer from significant aliasing effects unless they are sufficiently corrected using accurate ocean tide models.Long-term trends estimated from altimetry data are often also considerably affected by regional circulation changes, and by artificial effects arising from inconsistencies between different satellite missions. Here, we focused on two regions with high (>5 mm⋅yr–1) rates of long-term linear trend in sea level rise (LTSLR) around the Korean Peninsula (KP). We addressed the impacts of tidal correction and mission inconsistency in satellite altimetry data, and discussed the potential impacts of circulation changes on LTSLR. Because the LTSLR estimation is affected by the aliasing effects of altimetry data when the tidal motions are not corrected sufficiently, yet the correction depends on the performance of ocean tide models, we employed eight ocean tide models to correct altimetry data for comparison and validated the results against observations from 13 tide gauge (TG) stations around the KP. We also estimated LTSLR from 1993 to 2019 using annual mean sea level anomalies (SLAs) from two satellite (two-sat) and all 21 satellite (all-sat) missions, with corrections for ocean tides. The TPXO9 model showed the most reasonable spatial LTSLR rate pattern (∼3 mm⋅yr–1), with the smallest difference from TG observations. It performed best near the west coast where the tidal range was the largest and when using two-sat data, because of inconsistencies in all-sat altimetry data. In contrast, off the east coast, where the impact of tidal correction is negligible, the high (∼7 mm⋅yr–1) LTSLR rates were robust regardless of ocean tide models and altimetry missions, potentially driven by long-term changes in regional circulation. Our results highlight the importance of tidal correction and mission inconsistency for improving LTSLR estimations around the KP. They also have significant implications for determining regional sea level rise under changing circulation patterns, within and beyond the region.