Revisiting the ocean’s non-isostatic response to 5-day atmospheric loading: New results based on global bottom pressure records and numerical modeling

2021 ◽  
Author(s):  
Richard E. Thomson ◽  
Isaac V. Fine
Keyword(s):  
World Ocean ◽  
Warning System ◽  
Global Scale ◽  
Reanalysis Data ◽  
Ocean Model ◽  
Air Pressure ◽  
Bottom Pressure ◽  
Tsunami Warning System ◽  
Sea Level Fluctuations ◽  
The World

AbstractWe use bottom pressure records from 59 sites of the global tsunami warning system to examine the non-isostatic response of the World Ocean to surface air pressure forcing within the 4 to 6-day band. It is within this narrow “5-day” band that sea level fluctuations strongly depart from the isostatic inverted barometer response. Numerical simulations of the observed bottom pressures were conducted using a two-dimensional Princeton Ocean Model forced at the upper boundary by two versions of the air pressure loading: (a) an analytical version having the form of the westward propagating, 5-day Rossby-Haurwitz air pressure mode; and (b) an observational version based on a 16-year record of global-scale atmospheric reanalysis data with a spatial resolution of 2.5°. Simulations from the two models – consisting of barotropic standing waves of millibar amplitudes and near uniform phases in the Pacific, Atlantic and Indian oceans – are in close agreement and closely reproduce the observed bottom pressures. The marked similarity of the outputs from the two models and the ability of both models to accurately reproduce the seafloor pressure records indicates a pronounced dynamic response of the World Ocean to non-stationary air pressure fields resembling the theoretical Rossby-Haurwitz air pressure mode.

scholarly journals Potential deployment of offshore bottom pressure gauges and adoption of data assimilation for tsunami warning system in the western Mediterranean Sea

2019 ◽  
Vol 6 (1) ◽  
Author(s):  
Mohammad Heidarzadeh ◽  
Yuchen Wang ◽  
Kenji Satake ◽  
Iyan E. Mulia
Keyword(s):  
Data Assimilation ◽  
Warning System ◽  
Western Mediterranean ◽  
Tsunami Warning ◽  
Sensitivity Analyses ◽  
Bottom Pressure ◽  
Tsunami Warning System ◽  
Earthquake Scenarios ◽  
The North ◽  
Western Mediterranean Basin

AbstractWestern Mediterranean Basin (WMB) is among tsunamigenic zones with numerous historical records of tsunami damage and deaths. Most recently, a moderate tsunami on 21 May 2003 offshore Algeria, North Africa, was a fresh call for strengthening tsunami warning capabilities in this enclosed water basin. Here, we propose to deploy offshore bottom pressure gauges (OBPGs) and to adopt the framework of a tsunami data assimilation (TDA) approach for providing timely tsunami forecasts. We demonstrate the potential enhancement of the tsunami warning system through the case study of the 2003 Algeria tsunami. Four scenarios of OBPG arrangements involving 10, 5, 3 and 2 gauges are considered. The offshore gauges are located at distances of 120–300 km from the North African coast. The warning lead times are 20, 30, 48 and 55 min for four points of interest considered in this study: Ibiza, Palma, Sant Antoni and Barcelona, respectively. The forecast accuracies are in the range of 69–85% for the four OBPG scenarios revealing acceptable accuracies for tsunami warnings. We conclude that installation of OBPGs in the WMB can be helpful for providing successful and timely tsunami forecasts. We note that the OBPG scenarios proposed in this study are applicable only for the case of the 2003 Algeria tsunami. Further studies including sensitivity analyses (e.g., number of OBPG stations; earthquake magnitude, strike, epicenter) are required in order to determine OBPG arrangements that could be useful for various earthquake scenarios in the WMB.

scholarly journals The Phenomenon Of Emiliania Huxleyi In Aspects Of Global Climate And The Ecology Of The World Ocean

2021 ◽  
Vol 14 (2) ◽  
pp. 50-62
Author(s):  
Dmitry V. Pozdnyakov ◽  
Natalia V. Gnatiuk ◽  
Richard Davy ◽  
Leonid P. Bobylev
Keyword(s):  
Inorganic Carbon ◽  
Global Climate ◽  
World Ocean ◽  
Remote Sensing Data ◽  
Global Scale ◽  
Emiliania Huxleyi ◽  
Carbon Cycles ◽  
The North ◽  
The World ◽  
Ocean Carbon

Emiliania huxleyi (Lohmann) evolved from the genus Gephyrocapsa Kamptner (Prymneosiophyceae) of the coccolithophore family Naёlaerhadaceae. Over the past 100 thousand years E. huxleyi has acquired the status of the most ecologically predominant coccolithophore due to its remarkable adaptability to a variety of environmental conditions and interspecific competitiveness. E. huxleyi plays an important role in both the marine carbon system and carbon cycling between the atmosphere and ocean due to its ability to produce organic and inorganic carbon as well as to form massive blooms throughout the world ocean. This study examines both older information and recent findings to shed light on the current tendencies in the two-way interactions between E. huxleyi blooms and the immediate and global environment under conditions of climate change. The assembled knowledge has emerged from laboratory and mesocosm instrumental investigations, retrievals of satellite remote sensing data, machine learning/statistical analyses, and numerical simulations. Special attention is given to both the quantitative data reported over the last two decades on such interactions, and the only very recently appearing mid-term projections of E. huxleyi bloom dynamics across the world ocean. These blooms strongly affect the atmosphere and ocean carbon cycles. They reduce CO2 fluxes from by ~50% to ~150% as is documented for the North Atlantic, and on the global scale release particulate inorganic carbon as calcium calcite in the amounts assessed at 0.4 to 4.8 PgC/yr. At the same time, they are also sensitive to the atmospheric and oceanic state. This results in E. huxleyi blooms having an increased impact on the environment in response to ongoing global warming.

scholarly journals Distribution of32Si in the world ocean: Model compared to observation

1993 ◽  
Vol 7 (2) ◽  
pp. 463-474 ◽  
Author(s):  
Tsung-Hung Peng ◽  
Ernst Maier-Reimer ◽  
Wallace S. Broecker
Keyword(s):  
World Ocean ◽  
Ocean Model ◽  
The World

scholarly journals Sea Change: The World Ocean Circulation Experiment and the Productive Limits of Ocean Variability

2020 ◽  
pp. 016224392094993
Author(s):  
Jessica Lehman
Keyword(s):  
Ocean Circulation ◽  
Climate Modeling ◽  
World Ocean ◽  
Conveyor Belt ◽  
Global Scale ◽  
Global Knowledge ◽  
Ocean Variability ◽  
Decadal Scale ◽  
The World ◽  
World Ocean Circulation Experiment

The ability to quantify the relationship between the ocean and the atmosphere is an enduring challenge for global-scale science. This paper analyzes the World Ocean Circulation Experiment (WOCE, 1990–2002), an international oceanographic program that aimed to provide data for decadal-scale climate modeling and for the first time produce a “snapshot” of ocean circulation against which future change could be measured. WOCE was an ambitious project that drew on extensive international collaboration and emerging technologies that continue to play a significant role in how the global environment is known and governed. However, a main outcome of WOCE was an encounter with ocean variability: the notion that the ocean is governed not by the circular currents shown in the popular “conveyor-belt” diagram but by eddies, filaments, jets, and other nonlinear forces. This paper suggests the concept of “productive limits” as an analytic for understanding how ocean variability both prompted new forms of knowledge and the development of a global knowledge infrastructure that is contingent, uneven, and fully entwined with geopolitical dynamics.

scholarly journals About the possibility of registration of waves and sea level fluctuations in coastal areas of the World Ocean based on analysis of video on the Internet

2019 ◽  
Vol 488 (6) ◽  
pp. 667-672
Author(s):  
G. I. Dolgikh ◽  
V. K. Fishchenko ◽  
A. А. Goncharova
Keyword(s):  
Sea Level ◽  
World Ocean ◽  
Coastal Areas ◽  
The Internet ◽  
Oscillation System ◽  
Ship Waves ◽  
Sea Level Fluctuations ◽  
Real Time Analysis ◽  
The World ◽  
And Sea Level

The paper describes a technology of recording surface wave signals and sea level fluctuations in coastal areas of the World Ocean based on real-time analysis of live video from surveillance cameras presented on the Internet. A wave signal obtained with described method in the port of Crotone (Italy) is compared with data from nearby station of the Global Sea Level Observing System (GLOSS). The example demonstrates the high recording quality of the seiche oscillation system of the port with periods from 40 to 2 minutes, which is comparable to GLOSS. At the same time, unlike the GLOSS stations, signals obtained through video contain responses of even shorter-period (up to tens of seconds) seiches, swell waves, wind and ship waves.

scholarly journals Historically unprecedented global glacier decline in the early 21st century

2015 ◽  
Vol 61 (228) ◽  
pp. 745-762 ◽  
Author(s):  
Michael Zemp ◽  
Holger Frey ◽  
Isabelle Gärtner-Roer ◽  
Samuel U. Nussbaumer ◽  
Martin Hoelzle ◽  
...  
Keyword(s):  
21St Century ◽  
Global Scale ◽  
Ice Age ◽  
Early 21St Century ◽  
Sea Level Fluctuations ◽  
Decadal Scale ◽  
The World ◽  
Global Sea Level ◽  
Monitoring Service ◽  
The Impact

AbstractObservations show that glaciers around the world are in retreat and losing mass. Internationally coordinated for over a century, glacier monitoring activities provide an unprecedented dataset of glacier observations from ground, air and space. Glacier studies generally select specific parts of these datasets to obtain optimal assessments of the mass-balance data relating to the impact that glaciers exercise on global sea-level fluctuations or on regional runoff. In this study we provide an overview and analysis of the main observational datasets compiled by the World Glacier Monitoring Service (WGMS). The dataset on glacier front variations (∼42 000 since 1600) delivers clear evidence that centennial glacier retreat is a global phenomenon. Intermittent readvance periods at regional and decadal scale are normally restricted to a subsample of glaciers and have not come close to achieving the maximum positions of the Little Ice Age (or Holocene). Glaciological and geodetic observations (∼5200 since 1850) show that the rates of early 21st-century mass loss are without precedent on a global scale, at least for the time period observed and probably also for recorded history, as indicated also in reconstructions from written and illustrated documents. This strong imbalance implies that glaciers in many regions will very likely suffer further ice loss, even if climate remains stable.

Sign in / Sign up

Export Citation Format

Share Document