Gridding for auroral and ionospheric modeling

## Project description

## gridaurora

Discretizations of space (grids) and time conversions useful for aeronomy and auroral modeling.

Contents

### Install

python -m pip install -e .

Note: you will need a Fortran compiler on your system so that f2py can work. Yes, itβs possible on Windows too.

### Eigenprofiles

Currently GLOW and Rees-Sergienko-Ivanov are available (Transcar in future). You will need to separately install scivision/reesaurora and scivision/glowaurora. This is to keep the install process from becoming gigantic when you just want some of the models.

Once installed, select model by:

-M option | Model used |
---|---|

-M rees | Rees-Sergienko-Ivanov |

-M glow | Stan Solomonβs GLOW model |

#### Command Line Options

-t |
time, format yyyy-mm-ddTHH:MM:SSZ where Z sets UTC time zone |

-c |
lat, lon WGS84 geodetic degrees |

-o |
output, hDF5 ends in .h5 |

-M |
model select (see table above) |

-z |
min,max altitude to plot [km] |

#### Example Command

python MakeIonoEigenprofile.py -t 2013-01-31T09:00:00Z -c 65 -148 -o out.h5 -M rees

### Auroral Data Files

The functions in `gridaurora/calcemissions.py`, based on work by Zettergren, computes per-wavelength volume emission rate along a flux tube as a function of altitude along the tube.
Starting with quantities such as neutral densities computed by MSIS, differential number flux as a function of energy and altitude along the tube (this is what TRANSCAR computes), excitation cross sections as a function of energy, Franck-Condon factors and Einstein coefficients, the *prompt* volume emission rate may be computed.

#### precompute/vjeinfc.h5

compiled from tables in Vallance Jones *Aurora* 1974 and other sources by Matthew Zettergren, and corrected and put into HDF5 format by Michael Hirsch. The information within concerns:

- N2+1NG
- N
_{2}^{+}first negative group - N2_1PG
- N
_{2}first positive group - N2_2PG
- N
_{2}second positive group - N2+Meinel
- N
_{2}^{+}Meinel band - atomic
- atomic oxygen
- metastable
- metastable O and O
^{+}

##### Einstein coefficient matrix A

arranged A(πβ,πββ) where:

- πβ
- upper state vibrational levels, excited from ground state πβββ by particle impact
- πββ
- lower state vibrational levels, decayed into from the upper state

as discussed in Appendix C of Zettergren PhD thesis, Eqn. (C.2), photon volume emission rate follows the relation P_{πβ,πββ} = A(πβ,πββ) n_{πβ}

##### lamdba

wavelength in nanometers corresponding to the Einstein coefficient matrix `A`
except `atomic` that uses the reaction rates directly.

##### Franck-Condon factor fc

as described in Zettergren thesis Appendix C, specifically for Eqn (C.6-C.8), the Franck-Condon factors modify the total upper state excitation cross section multiplicitively.

### Function Description

function | description |
---|---|

ztanh.py | continuously varying grid using hyperbolic tangent. Inspired by suggestion from Prof. Matt Zettergren of ERAU. |

### References

[1] | Zettergren, M. Boston University, PhD Thesis, http://search.proquest.com/docview/304847517 |

## Project details

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## Download files

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Filename, size & hash SHA256 hash help | File type | Python version | Upload date |
---|---|---|---|

gridaurora-1.2.0-py3-none-any.whl (34.8 kB) Copy SHA256 hash SHA256 | Wheel | py3 | Mar 30, 2018 |

gridaurora-1.2.0.tar.gz (30.3 kB) Copy SHA256 hash SHA256 | Source | None | Mar 30, 2018 |