Sea-level variations have been a topic of interest for researchers for many years. In a recent study by Courtillot et al. (2020b), tide gauge data and satellite observations were analyzed using singular spectrum analysis (SSA) to determine their trends and periodic components. The tide gauge data used in the study covered a period of 200 years, while the satellite observations spanned over 30 years. The tide gauge data was subjected to SSA, which revealed annual to multi-decadal periods of ~90/80, 60, 30, 20, 10/11, and 4/5 years in both global sea-level based on tide gauges (GSLTG) and global sea-level based on combining tide gauges and satellite data (GSLl). These periods were found to be commensurable with the periods of the Jovian planets - Neptune (165 yr), Uranus (84 yr), Saturn (29 yr), and Jupiter (12 yr). The first SSA components accounted for most of the signal variance: 95% for GSLTG, 89% for GSLl, 98% for global pressure (GP), and 75% for polar motion (RP). The study also found that almost all the periods identified in sea-level changes, motion of the rotation pole RP, and evolution of global pressure GP could be associated with the Jovian planets. In addition to analyzing tide gauge data using SSA, Courtillot et al. also determined a smooth mathematical model of mean sea-level variations as a function of time using sine functions. This model consisted of eight sine components that represented an annual oscillation with peak-to-trough amplitude around 100 mm. The study also highlighted some uncertainties due to geography and tectonics but aimed to subject original data to minimal manipulation. To achieve this goal, recordings from only thirty-one stations were selected based on two criteria: the longest possible span of time and the best possible spatial coverage. The model obtained from these selected stations was called GSLTG.
Scientists studied how the sea level changes over time. They looked at data from measuring devices called tide gauges and satellites. They found patterns in the sea level changes that happen every 90/80, 60, 30, 20, 10/11, and 4/5 years. These patterns are similar to how some planets in our solar system move around the sun. They also made a model of how the sea level changes over time using math. The scientists were careful with their data but there may still be some things they don't know for sure.
Definitions
- Sea-level variations: Changes in the height of the ocean's surface.
- Tide gauge: A device that measures the height of water levels.
- Satellite observations: Data collected by satellites orbiting Earth.
- Singular spectrum analysis (SSA): A way to find patterns in data.
- Commensurable: When two things have similar or related characteristics.
- Jovian planets: The four outer planets in our solar system - Jupiter, Saturn, Uranus, and Neptune.
- Variance: How much something varies or changes over time.
- Pressure: Force exerted on an area by air or water molecules.
- Polar motion: Movement of Earth's rotational axis relative to its surface.
- Tectonics: Processes that shape Earth's crust and cause earthquakes and volcanic eruptions.
Sea-Level Variations: An Analysis of Tide Gauge Data and Satellite Observations
In recent years, sea-level variations have been a topic of great interest to researchers. In a study by Courtillot et al. (2020b), tide gauge data and satellite observations were analyzed using singular spectrum analysis (SSA) to determine their trends and periodic components. The results of the study provide insight into the relationship between sea-level changes and the Jovian planets.
Data Collection
The tide gauge data used in this study covered a period of 200 years, while the satellite observations spanned over 30 years. To ensure minimal manipulation of original data, recordings from only thirty-one stations were selected based on two criteria: the longest possible span of time and the best possible spatial coverage. This model was called GSLTG (Global Sea Level Based on Tide Gauges).
Singular Spectrum Analysis
The tide gauge data was subjected to SSA, which revealed annual to multi-decadal periods of ~90/80, 60, 30, 20, 10/11, and 4/5 years in both global sea-level based on tide gauges (GSLTG) and global sea-level based on combining tide gauges and satellite data (GSLl). These periods were found to be commensurable with the periods of the Jovian planets - Neptune (165 yr), Uranus (84 yr), Saturn (29 yr), and Jupiter (12 yr). The first SSA components accounted for most of the signal variance: 95% for GSLTG; 89% for GSLl; 98% for global pressure GP; 75% for polar motion RP.
Mathematical Modeling
In addition to analyzing tide gauge data using SSA, Courtillot et al. also determined a smooth mathematical model of mean sea-level variations as a function of time using sine functions. This model consisted of eight sine components that represented an annual oscillation with peak-to trough amplitude around 100 mm. The authors highlighted some uncertainties due to geography and tectonics but aimed to subject original data to minimal manipulation throughout their research process..
Conclusion
This study provides evidence that almost all periods identified in sea level changes can be associated with planetary motions such as those from Neptune(165yr), Uranus(84yr), Saturn(29yr) & Jupiter(12yr). Furthermore it has developed a mathematical model which accounts for 8 sine components representing an annual oscillation with peak–trough amplitudes around 100mm . Despite some uncertainties due to geography & tectonics , this research paper is significant in its attempt at minimizing manipulation when collecting original data & providing further insights into understanding how planetary motion affects our planet's climate change patterns .
Variations in sea-level, based on tide gauge data (GSLTG) and on combining tide gauges and satellite data (GSLl) are subjected to singular spectrum analysis (SSA), to determine their trends and periodic or quasi-periodic components. GLSTG increases by 90 mm from 1860 to 2020, a contribution of 0.56 mm/yr to the mean rise rate. Annual to multi-decadal periods of ~90/80, 60, 30, 20, 10/11, and 4/5 years are found in both GSLTG and GSLl. These periods are commensurable periods of the Jovian planets, combinations of the periods of Neptune (165 yr), Uranus (84 yr), Saturn (29 yr) and Jupiter (12 yr). These same periods are encountered in sea-level changes, motion of the rotation pole RP and evolution of global pressure GP, suggesting physical links. The first SSA components comprise most of the signal variance: 95% for GSLTG, 89% for GSLI, 98% for GP, 75% for RP. Laplace derived the Liouville-Euler equations that govern the rotation and translation of the rotation axis of any celestial body. He emphasized that one must consider the orbital kinetic moments of all planets in addition to gravitational attractions and concluded that the Earth's rotation axis should undergo motions that carry the combinations of periods of the Sun, Moon and planets. Almost all the periods found in the SSA components of sea-level (GSLl and GSLTG), global pressure (GP) and polar motion (RP), of their modulations and their derivatives can be associated with the Jovian planets. It would be of interest to search for data series with longer time spans, that could allow one to test whether the trends themselves could be segments of components with still longer periodicities (e.g. 175 yr Jose cycle).
