Skip to content
Snippets Groups Projects
Commit bcc94099 authored by Stefan Mauerberger's avatar Stefan Mauerberger
Browse files

Model and File-format description in reST

parent d67241e3
No related branches found
No related tags found
1 merge request!1Sphinx Documentation
......@@ -10,20 +10,7 @@ It can be applied to all cubic-spline based geomagnetic field models stored in t
package_documentation
command_line_interface
File format
-----------
However, care has to be taken that two header lines of the model files are formatted correctly and the list of spline knot point epochs starts only in line 3.
The first header line has to contain start and end epoch of the model as the first two numbers, any further information in that line is ignored.
The second header line has to start with three integers, which are the maximum spherical harmonic degree, a dummy that actually is not used, and the number of splines.
.. code-block:: none
:linenos:
1590 1990 Trailing text is ignored
14 0 163
1582.5000000000 1585.0000000000 1587.5000000000
...
.. include:: ../pymagglobal/dat/README.rst
License
-------
......
# Format description
The format that is used by pymagglobal is the same as the gufm1 model and the CALSxk models. The model files are structured as follows:
* The first line consits of the interval for which the model is valid, followed by several model parameters
* The second line contains three integers: the maximal spherical harmonic degree, a meaningless number and the number of splines
* Then follows a block of years, specifying the knots for the cubic B-splines and a block of coefficients, containing first all coefficients for the first knot, then all for the second etc.
The code is somewhat flexible with linebreaks. Only the linebreak after the first line is really necessary. If you have trouble parsing your own files, feel free to [contact](mailto:arthus@gfz-potsdam.de) one of the authors.
# Included models
pymagglobal comes with several models pre-included. Below is a description of those models.
| Model | Interval | Reference | Short description |
| ----- | -------- | --------- | ----------------- |
| gufm1 | 1590 – 1990 AD | Jackson, A., A. R. T. Jonkers and M. R. Walker (2000): Four centuries of geomagnetic secular variation from historical records. Phil. Trans. R. Soc. Lond. A 358, 957–990 | Based on historical and modern data |
| arhimag1k | 1000 – 2000 AD | R. Senftleben (2020) Earth’s magnetic field over the last 1000 years. PhD thesis, University of Potsdam | Combining archeomagnetic, volcanic and historical data |
| pfm9k.1a | 7000 BC – 1900 AD | Nilsson, A., R. Holme, M. Korte, N. Suttie and M. Hill (2014): Reconstructing Holocene geomagnetic field variation: new methods, models and implications. Geophys. J. Int., 198, 229-248 | Based on archeomagnetic, volcanic and sediment data; Sediment timescales adjusted to best fit |
| HFM.OL1.A1 | 8000 BC – 1990 AD | Panovska, S., M. Korte, C. Finlay and C. Constable (2015): Limitations in paleomagnetic data and modelling techniques and their impact on Holocene geomagnetic field models. Geophys. J. Int., 202, 402-418. | Based on archeomagnetic, volcanic and sediment data; Data outlier treatment and strength of temporal and spatial regularization somewhat different from the CALSxk models |
| CALS10k.2 | 8000 BC – 1990 AD | Constable, C., M. Korte and S. Panovska (2016): Persistent high paleosecular variation activity in Southern hemisphere for at least 10 000 years. Earth Planet. Sci. Lett.,453,78-86. | Based on archeomagnetic, volcanic and sediment data; Recent centuries constrained to agree in general with gufm1 |
| ARCH10k.1 | 8000 BC – 1990 AD | same as CALS10k.2 | Based only on archeomagnetic and volcanic data; Sparse data coverage for early millennia; Recent centuries constrained to agree in general with gufm1 |
| LSMOD.2 | 49.5 – 29.5 ka | Korte, M., M. C. Brown, S. Panovska and I. Wardinski (2019): Robust characteristics of the Laschamp and Mono Lake geomagnetic excursions: results from global field models. Frontiers in Earth Sciences, 7:86, doi:10.3389/feart.2019.00086 | Based on sediment and volcanic data; Closely adjacent sediment records stacked for regional consistency; Small correction to a sediment record location compared to LSMOD.1; use the `--longterm` flag, to pass dates as ka |
| GGF100k | 100 – 0 ka | Panovska, S., C. G. Constable and M. Korte (2018): Extending global continuous geomagnetic field reconstructions on timescales beyond human civilization. Geochem. Geophys. Geosys., 19, 4757-4772. doi:10.1029/2018GC007966 | Based on sediment, volcanic and archeomagnetic data; Temporally stronger smoothed (by temporal regularization) compared to the dedicated Laschamp excursion models; use the `--longterm` flag, to pass dates as ka |
File format description
-----------------------
The format that is used by pymagglobal is the same as the ``gufm1`` model and the ``CALSxk`` models.
Care has to be taken that two header lines of the model files are formatted correctly and the list of spline knot point epochs starts only in line 3.
The model files are structured as follows:
* The first line has to provide two numeric values:
Start and end of the epoch for which the model is valid.
Any trailing text is ignored.
* The second line contains three integers:
The maximal spherical harmonic degree, an unused number and the number of splines.
* Then follows a block of years, specifying the knots for the cubic B-splines and a block of coefficients, containing first all coefficients for the first knot, then all for the second etc.
.. code-block:: none
:linenos:
1590 1990 Trailing text is ignored
14 0 163
1582.5000000000 1585.0000000000 1587.5000000000 ...
The code is somewhat flexible with line breaks.
Only the line break after the first line is really necessary.
If you have trouble parsing your own files, feel free to `contact <mailto:arthus@gfz-potsdam.de>`_ one of the authors.
Included models
---------------
pymagglobal comes with several models pre-included. Below is a description of those models.
========== ================= ========= =================
Model Interval Reference Short description
========== ================= ========= =================
gufm1 1590 – 1990 AD [Jack00]_ Based on historical and modern data
arhimag1k 1000 – 2000 AD [Senf20]_ Combining archeomagnetic, volcanic and historical data
pfm9k.1a 7000 BC – 1900 AD [Nils14]_ Based on archeomagnetic, volcanic and sediment data; Sediment timescales adjusted to best fit
HFM.OL1.A1 8000 BC – 1990 AD [Pano15]_ Based on archeomagnetic, volcanic and sediment data; Data outlier treatment and strength of temporal and spatial regularization somewhat different from the ``CALSxk`` models
CALS10k.2 8000 BC – 1990 AD [Cons16]_ Based on archeomagnetic, volcanic and sediment data; Recent centuries constrained to agree in general with gufm1
ARCH10k.1 8000 BC – 1990 AD [Cons16]_ Based only on archeomagnetic and volcanic data; Sparse data coverage for early millennia; Recent centuries constrained to agree in general with ``gufm1``
LSMOD.2 49.5 – 29.5 ka [Kort19]_ Based on sediment and volcanic data; Closely adjacent sediment records stacked for regional consistency; Small correction to a sediment record location compared to ``LSMOD.1``; use the ``--longterm`` flag, to pass dates as ka
GGF100k 100 – 0 ka [Pano18]_ Based on sediment, volcanic and archeomagnetic data; Temporally stronger smoothed (by temporal regularization) compared to the dedicated Laschamp excursion models; use the ``--longterm`` flag, to pass dates as ka
========== ================= ========= =================
.. rubric:: References
.. [Jack00] Jackson, A., A. R. T. Jonkers and M. R. Walker (2000): Four centuries of geomagnetic secular variation from historical records. Phil. Trans. R. Soc. Lond. A 358, 957–990
.. [Senf20] Senftleben, R. (2020): Earth’s magnetic field over the last 1000 years. PhD thesis, University of Potsdam
.. [Nils14] Nilsson, A., R. Holme, M. Korte, N. Suttie and M. Hill (2014): Reconstructing Holocene geomagnetic field variation: new methods, models and implications. Geophys. J. Int., 198, 229-248
.. [Pano15] Panovska, S., M. Korte, C. Finlay and C. Constable (2015): Limitations in paleomagnetic data and modelling techniques and their impact on Holocene geomagnetic field models. Geophys. J. Int., 202, 402-418.
.. [Cons16] Constable, C., M. Korte and S. Panovska (2016): Persistent high paleosecular variation activity in Southern hemisphere for at least 10 000 years. Earth Planet. Sci. Lett.,453,78-86.
.. [Kort19] Korte, M., M. C. Brown, S. Panovska and I. Wardinski (2019): Robust characteristics of the Laschamp and Mono Lake geomagnetic excursions: results from global field models. Frontiers in Earth Sciences, 7:86, doi:10.3389/feart.2019.00086
.. [Pano18] Panovska, S., C. G. Constable and M. Korte (2018): Extending global continuous geomagnetic field reconstructions on timescales beyond human civilization. Geochem. Geophys. Geosys., 19, 4757-4772. doi:10.1029/2018GC007966
0% Loading or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment