| NSF Org: |
OCE Division Of Ocean Sciences |
| Recipient: |
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| Initial Amendment Date: | July 15, 2021 |
| Latest Amendment Date: | July 15, 2021 |
| Award Number: | 2048788 |
| Award Instrument: | Standard Grant |
| Program Manager: |
Baris Uz
bmuz@nsf.gov (703)292-4557 OCE Division Of Ocean Sciences GEO Directorate for Geosciences |
| Start Date: | July 15, 2021 |
| End Date: | June 30, 2024 (Estimated) |
| Total Intended Award Amount: | $283,001.00 |
| Total Awarded Amount to Date: | $283,001.00 |
| Funds Obligated to Date: |
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| History of Investigator: |
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| Recipient Sponsored Research Office: |
1000 HILLTOP CIR BALTIMORE MD US 21250-0001 (410)455-3140 |
| Sponsor Congressional District: |
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| Primary Place of Performance: |
1000 Hilltop Circle Baltimore MD US 21250-0001 |
| Primary Place of
Performance Congressional District: |
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| Unique Entity Identifier (UEI): |
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| Parent UEI: |
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| NSF Program(s): | PHYSICAL OCEANOGRAPHY |
| Primary Program Source: |
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| Program Reference Code(s): |
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| Program Element Code(s): |
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| Award Agency Code: | 4900 |
| Fund Agency Code: | 4900 |
| Assistance Listing Number(s): | 47.050 |
ABSTRACT
This award is funded in whole or in part under the American Rescue Plan Act of 2021 (Public Law 117-2).
The electrically conducting ocean generates electric currents and associated magnetic fields as it flows through the Earth?s magnetic field. These electric currents vary in time with changes in the ocean?s electrical conductivity and velocity, and can be detected remotely by land and satellite magnetometers. There is therefore an opportunity to recover ocean flow and conductivity variability from magnetometer data. Extracted signals are very useful, as they represent depth integrals of conductivity and conductivity transport, which can stand as proxies for heat content and heat transport over the measurement durations ? quantities that have been hard to measure with other methods. Magnetometer data come from hundreds of land magnetic observatories (some with hourly data extending back a century) as well as from modern satellite magnetic surveys. The proposed work will extract past ocean variability from long, land geomagnetic observatory records, develop forward models for predicting the oceanic magnetic fields, and ultimately develop data assimilation strategies for both land and satellite observations. This project will examine both fundamental components of ocean electrodynamics and exploit a new data type for monitoring and understanding ocean variability and steric sea-level changes. The electromagnetic field modules in the model used here will be made publicly available. Workshops will be organized to introduce students and early career scientists to analysis of geomagnetic observatory data and its connection to oceanographic applications.
Extracting oceanic signals from magnetic data is challenging because the signals are relatively weak and a priori knowledge of the signal is required. This proposal demonstrates method feasibility with preliminary work on a century of ocean tidal variability extracted from the Honolulu geomagnetic observatory data. These independent data confirm a trend toward increasing tidal amplitudes previously found in Honolulu tide gauge data that has been attributed to ocean warming. The Honolulu series will be thoroughly analyzed to optimize the extraction of ocean tidal signals. The methods will be extended to extract other predictable ocean signals there, such as inertial oscillations and interannual oscillations. Similar methods will be applied to geomagnetic observatory data from other locations. Extensions will include canonical-correlation multivariate analyses of data from multiple locations as well as from satellite data and geomagnetic field models. Additional tasks will involve the development and use of forward models to calculate the magnetic (and electric) fields given tidal and circulation ocean model flow. Extracted signals represent depth integrals of conductivity and conductivity transport, useful as proxies for heat content and heat transport over the measurement durations ? quantities that have been hard to measure with other methods. Thus, in addition to addressing fundamental components of ocean electrodynamics the proposed work will be useful in exploiting a new data type for monitoring and understanding ocean variability and steric sea-level changes.
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
PROJECT OUTCOMES REPORT
Disclaimer
This Project Outcomes Report for the General Public is displayed verbatim as submitted by the Principal Investigator (PI) for this award. Any opinions, findings, and conclusions or recommendations expressed in this Report are those of the PI and do not necessarily reflect the views of the National Science Foundation; NSF has not approved or endorsed its content.
The work in this project has been reported in the publications below. Also included in the list are the articles in the collection in which the PI (R. Tyler) served as guest editor, "Magnetometric Remote Sensing of Earth and Planetary Oceans," published as a theme issue in Proc. Royal Soc. A, in December, 2024. This issue should serve as a useful collection describing developments in the field as well as the contributions related to this project.
The total number of publications below in which the team has authored during the work for this project are five.
Trossman, D. S., R. H. Tyler, 2022a: A Prototype for Remote Monitoring of Ocean Heat Content Anomalies. Journal of Atmospheric and Oceanic Technology, 39(5), 667-688; https://doi.org/10.1175/JTECH-D-21-0037.1
Trossman, D. S., R. H. Tyler, 2022b: Oceanic electrical conductivity variability from observations and its budget from an ocean state estimate. Geophysical Research Letters, 49, e2022GL100453; https://doi.org/10.1029/2022GL100453
The list of references in the collection mentioned:
Baba, Toshitaka, Zhiheng Lin, Takuto Minami, and Hiroaki Toh. “Harnessing Electromagnetic Data for Tsunami Source Estimation: A Comprehensive Review.” Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 382, no. 2286 (December 23, 2024): 20240082. https://doi.org/10.1098/rsta.2024.0082.
Cochrane, C. J., S. D. Vance, T. A. Nordheim, M. J. Styczinski, A. Masters, and L. H. Regoli. “In Search of Subsurface Oceans Within the Uranian Moons.” Journal of Geophysical Research: Planets 126, no. 12 (December 2021): e2021JE006956. https://doi.org/10.1029/2021JE006956.
Finlay, Christopher C., Jakub Velímský, Clemens Kloss, and Rasmus M. Blangsbøll. “Satellite Monitoring of Long Period Ocean-Induced Magnetic Field Variations.” Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 382, no. 2286 (December 23, 2024): 20240077. https://doi.org/10.1098/rsta.2024.0077.
Grayver, Alexander, Christopher C. Finlay, and Nils Olsen. “Magnetic Signals from Oceanic Tides: New Satellite Observations and Applications.” Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 382, no. 2286 (December 23, 2024): 20240078. https://doi.org/10.1098/rsta.2024.0078.
Khurana, Krishan K., Jiang Liu, Julie Castillo-Rogez, Corey Cochrane, Francis Nimmo, and Louise M. Prockter. “Dual-Frequency Electromagnetic Sounding of a Triton Ocean from a Single Flyby.” Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 382, no. 2286 (December 23, 2024): 20240087. https://doi.org/10.1098/rsta.2024.0087.
Lin, Zhiheng. “Estimation of Tsunami Direction and Horizontal Velocity Field from Tsunami Magnetic Field.” Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 382, no. 2286 (December 23, 2024): 20240083. https://doi.org/10.1098/rsta.2024.0083.
Minami, Takuto. “Properties of Tsunami-Generated Electromagnetic Variation Observed on Islands.” Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 382, no. 2286 (December 23, 2024): 20240084. https://doi.org/10.1098/rsta.2024.0084.
Trossman, David S., Robert H. Tyler, and Helen R. Pillar. “Physical Oceanographic Factors Controlling the Ocean Circulation-Induced Magnetic Field.” Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 382, no. 2286 (December 23, 2024): 20240076. https://doi.org/10.1098/rsta.2024.0076.
Tyler, Robert H., and David S. Trossman. “Oceanic and Ionospheric Tidal Magnetic Fields Extracted from Global Geomagnetic Observatory Data.” Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 382, no. 2286 (December 23, 2024): 20240088. https://doi.org/10.1098/rsta.2024.0088.
Tyler, Robert, Hiroaki Toh, Krishan Khurana, and Ikuko Fujii. “Magnetometric Remote Sensing of Earth and Planetary Oceans.” Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 382, no. 2286 (December 23, 2024): 20240089. https://doi.org/10.1098/rsta.2024.0089.
Velímský, J., and L. Šachl. “Sensitivity of M2 Tidal Magnetic Signals to Seasonal and Spatial Variations of Ocean Electric Conductivity.” Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 382, no. 2286 (December 23, 2024): 20240079. https://doi.org/10.1098/rsta.2024.0079.
Last Modified: 01/21/2025
Modified by: Robert H Tyler
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