pyrfu.pyrf.dynamic_press module#

pyrfu.pyrf.dynamic_press.dynamic_press(n_s, v_xyz, specie: str = 'ions')[source]#

Computes dynamic pressure.

Parameters:

  • n_s (xarray.DataArray) – Time series of the number density of the specie.

  • v_xyz (xarray.DataArray) – Time series of the bulk velocity of the specie.

  • specie ({"ions", "electrons"}, Optional) – Specie. Default “ions”.

Returns:

p_dyn – Time series of the dynamic pressure of the specie.

Return type:

xarray.DataArray

Examples

>>> from pyrfu import mms, pyrf

Time interval

>>> tint = ["2019-09-14T07:54:00.000", "2019-09-14T08:11:00.000"]

Spacecraft index

>>> mms_id = 1

Load ion bulk velocity and remove spintone

>>> v_xyz_i = mms.get_data("vi_gse_fpi_fast_l2", tint, mms_id)
>>> st_xyz_i = mms.get_data("sti_gse_fpi_fast_l2", tint, mms_id)
>>> v_xyz_i = v_xyz_i - st_xyz_i

Ion number density

>>> n_i = mms.get_data("ni_fpi_fast_l2", tint, mms_id)

Compute dynamic pressure

>>> p = pyrf.dynamic_press(n_i, v_xyz_i, specie="ions")