Swipe

The Swipe model is an empirical model of high-latitude ionospheric electrodynamics based on Swarm ion drift measurements, and Swarm and CHallenging Minisatellite Payload (CHAMP) magnetic field measurements. The model does not assume hemispheric asymmetry, and provides independent estimates of all quantities in each hemisphere.

The parameters that are available for calculation/plotting are: electric potential (scalar) electric field E (vector) convection v = - cross(E, B) (vector) height-integrated electromagnetic work = dot(J, E) (scalar) in the earth's rotating frame of reference, with J given by the AMPS model and E by Swarm Hi-C Hall and Pedersen conductances (scalars) Poynting flux (scalar)

Not a caveat, but a comment: Lots of examples are provided in the tests/ directory. There is also an example Jupyter notebook given as one of the 'Relevant Links' section.

v : float solar wind velocity in km/s By : float IMF GSM y component in nT Bz : float IMF GSM z component in nT tilt : float dipole tilt angle in degrees f107 : float F10.7 index in s.f.u.

The solar wind/IMF parameters are all calculated as the average of the preceding 20 min of the relevant OMNI parameters at 1-min resolution, after time-shifting to the bow shock of

Optional inputs for SWIPE class minlat : float, optional low latitude boundary of grids (default 60) maxlat : float, optional low latitude boundary of grids (default 89.99) dr : int, optional latitudinal spacing between equal area grid points (default 2 degrees) M0 : int, optional number of grid points in the most poleward circle of equal area grid points (default 4) resolution: int, optional resolution in both directions of the scalar field grids (default 100) min_emwork*: float,optional Threshold minimum value of EM work for returning Hall and Pedersen conductances min_hall*: float,optional Threshold minimum value of Hall conductance for returning Hall and Pedersen conductances

*Note on thresholds: These are used to decide whether an estimate of the conductances is reliable. If these thresholds are not met, the conductances are masked

get_potential method: ionospheric potential in kV

get_efield_MA: high-latitude electric field components in Modified Apex coordinates, mV/m

get_convection_vel_MA: high-latitude ionospheric convection components in Modified Apex coordinates (m/s)

get_emwork: electromagnetic work (dot(E, J)) in mW/m²

get_conductances: Pedersen and Hall conductances in mho

get_poynting_flux_dipole: Calculate the field-aligned Poynting flux in mW/m² by translating Earth’s magnetic field to a dipole

get_poynting_flux: Calculate the field-aligned Poynting flux in mW/m² taking stock of distortions in the Earth’s magnetic field. NOTE: A date/time must be provided in order to calculate Poynting flux using the appropriate Modified Apex basis vectors.

Functions useful for calculating model parameters along a satellite track with variable solar wind conditions

get_v: Given a time series of glat, glon, height, time, v, By, Bz, tilt, f107, calculate the high-latitude perpendicular-to-B convection in either geodetic or Modified Apex coordinates

get_v: Given a time series of glat, glon, height, time, v, By, Bz, tilt, f107, calculate the high-latitude perpendicular-to-B convection in either geodetic or Modified Apex coordinates

get_E: Given a time series of glat, glon, height, time, v, By, Bz, tilt, f107, calculate the high-latitude perpendicular-to-B electric field in either geodetic or Modified Apex coordinates

get_pflux: Given a time series of glat, glon, height, time, v, By, Bz, tilt, f107, calculate the high-latitude Poynting flux vector (including perpendicular-to-B components) in either geodetic or Modified Apex coordinates