Consistent intra-centennial variations of length of day, global mean sea surface temperature, and global mean sea level

2021 ◽  
Author(s):  
Viacheslav A. Bezverkhnii ◽  
Aleksandr N. Gruzdev
Keyword(s):  
Surface Temperature ◽  
Sea Surface Temperature ◽  
Sea Level ◽  
Sea Surface ◽  
Length Of Day ◽  
Mean Sea Level ◽  
Mean Sea Surface ◽  
Global Mean Sea Level ◽  
Global Mean

scholarly journals Kinematics of global mean thermosteric sea level during 1993–2019

2021 ◽  
Vol 11 (1) ◽  
pp. 75-82
Author(s):  
H. Bâki İz
Keyword(s):  
Time Series ◽  
Sea Level ◽  
Temperature Gradients ◽  
Sea Surface ◽  
Sea Level Changes ◽  
Mean Sea Level ◽  
Mean Sea Surface ◽  
Global Mean Sea Level ◽  
Global Sea Level ◽  
Global Mean

Abstract Because oceans cover 71% of Earth’s surface, ocean warming, consequential for thermal expansion of sea water, has been the largest contributor to the global mean sea level rise averaged over the 20 th and the early 21 st century. This study first generates quasi-observed monthly globally averaged thermosteric sea level time series by removing the contributions of global mean sea level budget components, namely, Glaciers, Greenland, Antarctica, and Terrestrial Water Storage from satellite altimetry measured global sea level changes during 1993–2019. A baseline kinematic model with global mean thermosteric sea level trend and a uniform acceleration is solved to evaluate the performance of a rigorous mixed kinematic model. The model also includes coefficients of monthly lagged 60 yearlong cumulative global mean sea surface temperature gradients and control variables of lunisolar origins and representations for first order autoregressive disturbances. The mixed kinematic model explains 94% (Adjusted R 2)1 of the total variability in quasi-observed monthly and globally averaged thermosteric time series compared to the 46% of the baseline kinematic model’s Adjusted R 2. The estimated trend, 1.19±0.03 mm/yr., is attributed to the long-term ocean warming. Whereas eleven statistically significant (α = 0.05) monthly lagged cumulative global mean sea surface temperature gradients each having a memory of 60 years explain the remainder transient global mean thermosteric sea level changes due to the episodic ocean surface warming and cooling during this period. The series also exhibit signatures of a statistically significant contingent uniform global sea level acceleration and periodic lunisolar forcings.

Assessment of the Jason-2 Extension to the TOPEX/Poseidon, Jason-1 Sea-Surface Height Time Series for Global Mean Sea Level Monitoring

2010 ◽  
Vol 33 (sup1) ◽  
pp. 447-471 ◽  
Author(s):  
B. D. Beckley ◽  
N. P. Zelensky ◽  
S. A. Holmes ◽  
F. G. Lemoine ◽  
R. D. Ray ◽  
...  
Keyword(s):  
Time Series ◽  
Sea Level ◽  
Sea Surface Height ◽  
Sea Surface ◽  
Mean Sea Level ◽  
Global Mean Sea Level ◽  
Global Mean ◽  
Level Monitoring

scholarly journals VARIATIONS OF SEA LEVEL AND SEA SURFACE TEMPERATURE IN THE CALDERA OF SANTORINI ISLAND , SOUTHERN AEGEAN SEA

2018 ◽  
Vol 36 (2) ◽  
pp. 1077 ◽  
Author(s):  
K. Albanakis ◽  
M. Styllas ◽  
V. Yfantis
Keyword(s):  
Surface Temperature ◽  
Sea Surface Temperature ◽  
Sea Level ◽  
Missing Values ◽  
Thermal Structure ◽  
Monitoring Network ◽  
Volcanic Eruptions ◽  
Sea Surface ◽  
Atmospheric Forcing ◽  
Mean Sea Level

Analyses of sea level records within the Caldera of Santorini Island revealed the significance of both océanographie and atmospheric forcing on the observed signals. Sea level (msl) and sea surface temperature (sst) data were obtained from the four stations of the REMOS monitoring network. Out of the four stations Gialos station is located on the caldera whereas the remaining three (Erinia, Taxiarhis and Agios Nikolaos) are located on the young volcanic islands of Palaia and Nea Kameni. The record of sea level data contained a number of gaps. When possible, (i.e. small gaps) missing values were estimated with linear interpolation. Harmonic analysis on continuous parts of the record revealed a mixed type of tide with similar Nf values for the four stations, a result of their locations being close to each other. No co-oscillation phenomena were found within the caldera. Sea level at Taxiarhis station is affected more by atmospheric forcing and shallow water effects in contrast with Gialos station where mean sea level displays significant correlation (r=0.62) with sea surface temperature at lags 2-6 days. The annual cycle of mean sea level (amplitude=5.74cm) responds to seasonal variations in the thermal structure of the waters, and together with the semiannual cycle explains 9.02% of the variance in the annual frequency band. Existing data are not sufficiently long to develop a model, which will reconstruct sea level variability resulting from océanographie and meteorological forcing and will be used for the detection of ground movements from future volcanic eruptions.

Constraining Wind Stress Products with Sea Surface Height Observations and Implications for Pacific Ocean Sea Level Trend Attribution*

2012 ◽  
Vol 25 (23) ◽  
pp. 8164-8176 ◽  
Author(s):  
Shayne McGregor ◽  
Alexander Sen Gupta ◽  
Matthew H. England
Keyword(s):  
Sea Level ◽  
Wind Stress ◽  
Surface Wind ◽  
Sea Surface Height ◽  
Sea Surface ◽  
Water Model ◽  
Mean Sea Level ◽  
Sea Level Trend ◽  
Global Mean Sea Level ◽  
Global Mean

Abstract A number of global surface wind datasets are available that are commonly used to examine climate variability or trends and as boundary conditions for ocean circulation models. However, discrepancies exist among these products. This study uses observed Archiving, Validation, and Interpretation of Satellite Oceanographic (AVISO) sea surface height anomalies (SSHAs) as a means to help constrain the fidelity of these products in the tropical region. Each wind stress product is used to force a linear shallow water model (SWM) and the resulting hindcast thermocline depth anomalies are converted to SSHAs. The resulting SSHAs are then assessed to see how well they reproduce the dominant EOF modes of observed variability and the regional (global mean removed) sea level trend (1993–2007) in each of the three ocean basins. While the results suggest that all wind datasets reproduce the observed interannual variability with reasonable fidelity, the two SWM hindcasts that produce the observed linear trend with the highest fidelity are those incorporating interim ECMWF Re-Analysis (ERA-Interim) and Wave- and Anemometer-Based Sea Surface Wind (WASWind) forcing. The role of surface wind forcing (i.e., upper ocean heat content redistribution) versus global mean sea level change (i.e., including the additional contributions of glacier and ice sheet melt along with ocean thermal expansion) on the recent dramatic increase in western equatorial Pacific island sea level is then reassessed. The results suggest that the recent sea level increase cannot be explained solely by wind stress forcing, regardless of the dataset used; rather, the global mean sea level signal is required to fully explain this observed recent abrupt sea level rise and to better explain the sea level variability of the last 50–60 years.

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