Extracting ocean‐generated tidal magnetic signals from Swarm data through satellite gradiometry. Issue 7 (14th April 2016)

• Record Type: Journal Article
• Authors: Sabaka, Terence J.; Tyler, Robert H.; Olsen, Nils
• Is Part Of: Geophysical research letters. Volume 43:Issue 7(2016)
• Page Start: 3237
• Page End: 3245
• Publication Date: 2016-04-14
• Subjects: geomagnetism -- Swarm -- gradiometry -- oceanic tides; Geophysics -- Periodicals; Planets -- Periodicals; Lunar geology -- Periodicals; 550
• DOI: 10.1002/2016GL068180
• Languages: English
• ISSNs: 0094-8276

Abstract

Abstract: Ocean‐generated magnetic field models of the Principal Lunar, M 2, and the Larger Lunar elliptic, N 2, semidiurnal tidal constituents were estimated through a "Comprehensive Inversion" of the first 20.5 months of magnetic measurements from European Space Agency's (ESA) Swarm satellite constellation mission. While the constellation provides important north‐south along‐track gradiometry information, it is the unique low‐spacecraft pair that allows for east‐west cross‐track gradiometry. This latter type is crucial in delivering an M 2 estimate of similar quality with that derived from over 10 years of CHAMP satellite data but over a shorter interval, at higher altitude, and during more magnetically disturbed conditions. Recovered N 2 contains nonoceanic signal but is highly correlated with theoretical models in regions of maximum oceanic amplitude. Thus, satellite magnetic gradiometry may eventually enable the monitoring of ocean electrodynamic properties at temporal resolutions of 1 to 2 years, which may have important implications for the inference of ocean temperature and salinity. Key Points: Oceanic M 2 tidal magnetic signal extracted from only 20.5 months of Swarm data compared to >3.5 years of CHAMP data Swarm gradiometry allows for extraction from higher‐altitude data compared to CHAMP Swarm gradiometry allows for extraction during more magnetically disturbed times compared to CHAMP