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IAPS - Wind velocity-magnetic field correlation coefficient data of solar wind streams
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.. contents:: Table of contents

The velocity - magnetic field (v-b) correlation coefficient unables to identify Alfvénic solar wind intervals (along with almost constant magnetic field magnitude and proton number density). It is derived as the ratio between the covariance of velocity and magnetic field (in Alfvén units) components and the product of their standard deviations, in a time window ranging between tens of minutes to hours. In principle, this formula should be applied to every component of the velocity (V_i) and magnetic fields (B_i) (with i = R, T, N in RTN coordinate system or i = X, Y, Z in GSE coordinate system). The total correlation coefficient is then derived as the average from the three components. However, for the sake of simplicity, we consider only the N component since more Alfvénic than the other two.

References
~~~~~~~~~~

D’Amicis et al, GRL, 34, L05108, 2007; Frontiers in Physics, 8, 541, 2020

Telloni et al, ApJ, 916, 64, 2021

D’Amicis et al, A&A, 656, A21, 2021

Tu et al., JGR, 94, 11739, 1989

Dataset summary
~~~~~~~~~~~~~~~

.. list-table::

  * - **internal_name:**
    - inaf_vbcorr_wind_tableset
  * - **publisher:**
    - INAF-IAPS, Fisica dei Plasmi Spaziali e Space Weather
  * - **alph_code:**
    - 24C
  * - **id_tmp:**
    - 98
  * - **short_name:**
    - wind_v-b_corr
  * - **identifier:**
    - aspis://inaf/vbcorr_wind_tableset
  * - **dynamic:**
    - static
  * - **size:**
    - 35MB
  * - **format:**
    - csv
  * - **type:**
    - tableset
  * - **records_number:**
    - 538
  * - **time_start:**
    - 1998-10-01
  * - **time_stop:**
    - 2022-05-06
  * - **spatial:**
    - L1
  * - **messenger:**
    - protons
  * - **spectral_min:**
    - 0
  * - **spectral_max:**
    - 0
  * - **spectral_units:**
    - -
  * - **observable:**
    - SW
  * - **latest update:**
    - 2024-04-04 02:05:02

Columns specification
~~~~~~~~~~~~~~~~~~~~~

.. list-table:: 
   :widths: 7 20 15 10 48
   :align: right 
   :header-rows: 1

   * - progr
     - column
     - units
     - type
     - description
   * - 1
     - time
     - UTC
     - datetime
     - 2017-03-25T00:00:06 [UTC] - the UTC time associated to the masure
   * - 2
     - vb_coeff_corr
     - number
     - float
     - -0.98  [dimensionless] the Pearson's correlation coefficient between the normal components of velocity and magnetic field
   * - 3
     - sample
     - number
     - int
     - 75 [samples] the number of observations available in the 30-min window
   * - 4
     - scale
     - min
     - int
     - 30 [minutes] the length of the window, i.e. 30 min
