New Magnetic Field Models of the Moon

Researcher

Dhananjay Ravat, University of KentuckyFollow
Michael E. Purucker, National Aeronautics and Space AdministrationFollow
Nils Olsen, Technical University of Denmark, DenmarkFollow

Researcher ORCID Identifier

Dhananjay Ravat: https://orcid.org/0000-0003-1962-4422

Michael E. Purucker: https://orcid.org/0000-0002-5519-7977

Nils Olsen: https://orcid.org/0000-0003-1132-6113

Dataset Creation Date

2-2-2020

Release Date

2-3-2020

Publisher

University of Kentucky Libraries

Description

We use L1-norm model regularization of |B_r| component at the surface on magnetic monopoles bases and along-track magnetic field differences alone (without vector observations) to derive high quality global magnetic field models at the surface of the Moon. The practical advantages to this strategy are: monopoles are more stable at closer spacing in comparison to dipoles, improving spatial resolution; L1-norm model regularization leads to sparse models which may be appropriate for the Moon which has regions of localized magnetic field features; and along-track differences reduce the need for ad-hoc external field noise reduction strategies. We examine also the use of Lunar Prospector (LP) and SELENE/Kaguya magnetometer data, combined and separately, and find that the LP along-track vector field differences lead to surface field models that require weaker regularization and, hence, result in higher spatial resolution. Significantly higher resolution and higher amplitude surface magnetic fields can be derived over localized regions of high amplitude anomalies (due to their higher signal-to-noise ratio). These high resolution field models are also compared with the results of Surface Vector Mapping (SVM) approach of Tsunakawa et al. (2015). Finally, the monopoles- as well as dipole-based patterns of the Serenitatis high amplitude magnetic feature has characteristic textbook patterns of B_r and B_ component fields from a nearly vertically downwardly magnetized source region and it implies that the principal source of the anomaly was formed when the region was much closer to the north magnetic pole of the Moon.

Digital Object Identifier (DOI)

https://doi.org/10.13023/9wpe-tt68

Rights

© 2020 Ravat, Purucker, and Olsen

This dataset is distributed under Creative Commons Public Domain Dedication (https://creativecommons.org/share-your-work/public-domain/cc0/), which permits unrestricted use, distribution, and reproduction in any medium.

Supporting Information

The data file “Ravatetal_JGR2020_LunarL1MagneticModelFields_LPgrad.dat“ contains 6 columns: Longitude (degree), Latitude (degree), Br, Btheta, Bphi and Total Field components of the magnetic field, 6485401 data lines. The data are at the ellipsoid surface of the Moon with equatorial radius 1738.1 km and polar radius 1736.0 km.

Data images are provided for cross-checking purposes and are available for download as the first additional file listed at the end of this record.

The following three ASCII files contain higher resolution subsets of the preferred surface field models described in the Journal of Geophysical Research: Planets manuscript of Ravat et al. (2020). The fields are shown in the manuscript for cross-checking. The fields in the files have 7 columns: Longitude (degree), Latitude (degree), Br, Btheta, Bphi and Total Field components of the magnetic field at the lunar surface.

• Subset 1: Ravatetal2020_LunarL2resL1_ReinerGamma_Brtptot.dat (for the Reiner Gamma swirl region),
• Subset 2: Ravatetal2020_LunarL2resL1_Serenitatis_Brtptot.dat (for the Serenitatis region), and
• Subset 3: Ravatetal2020_LunarL2resL1_VonKarman_Brtptot.dat (for the Von Kármán region).

These three files are available for download as the additional files listed at the end of this record.

Other additional files include:

• LP1999_L1_d450.cof: See header records for description.
• SVM_minus_LP99_L1.pdf: This is the map of differences between the model of the this study and the previous best model.

File Format

Dataset: DAT file (.dat)

Data image file: Adobe Acrobat Document (.pdf)

Data subset 1: DAT file (.dat)

Data subset 2: DAT file (.dat)

Data subset 3: DAT file (.dat)

Dataset: COF file (.cof)

Figure file: Adobe Acrobat Document (.pdf)

File Size

Dataset: 88 MB (compressed)

Data image file: 1.22 MB

Data subset 1: 917 KB

Data subset 2: 1.54 MB

Data subset 3: 1.69 MB

Dataset: 4.08 MB

Figure file: 3.18 MB

Version

1

Spatial Coverage

The Moon (global)

Funding Information

NASA research grant NNX16AN51G to DR.

Related Content

Ravat, D., Purucker, M. E., & Olsen, N. (2020). Lunar magnetic field models from Lunar Prospector and SELENE/Kaguya along‐track magnetic field gradients. Journal of Geophysical Research: Planets, 125, e2019JE006187. https://doi.org/10.1029/2019JE006187

Recommended Citation

Ravat, Dhananjay; Purucker, Michael E.; and Olsen, Nils, "New Magnetic Field Models of the Moon" (2020). Earth and Environmental Sciences Research Data. 2.
https://uknowledge.uky.edu/ees_data/2