OMNIWeb Plus Browser
to select different options to produce plots, listings or output files.
SW Wind 5min Magnetic Field, SWE Plasma definitive and their derived parameters

This new interface allows the OMNI users ( to calculate more accurately a few "OMNI derived parameters" that are currently included in the OMNI 5-min dataset. These parameters are the Flow presure, Plasma Beta, Alfven Mach Number, Magnetosonic Mach Number, and Quasi-Invariant(QI). To create the new derived parameters we have taken into account the really measured values of the Wind/SWE Alpha Density.
Using this new interface, a user can compare these derived parameters: (1) as based on the Proton Density only, (2) as calculated by the technique used in the original OMNI database = Alpha Particles Density (Na) = 5% of Proton Density (Np); and (3) as calculated based on the Alpha Density real measurements (Na) along with the Proton Density (Np).
All details of the above parameters calculation can be found at the OMNI Web site We believe that the newly derived parameters (that are based on the Proton and real Alpha densities) can be more realistic for the periods when the SW plasma is significantly disturbed (e.g., during CME, magnetic storms, etc.) when the Alpha Density might be quite different from the values originally used in OMNI2 dataset (Na= 5% of Np).
Similar as in the OMNI2 database, we use here same assimptions for the ratios of: (1) Alpha (Ta) to Proton (Tp) temperatures as Ta/Tp = 4, (2) Electron Te = 1.4*10**5 and Alpha Paticles Speed (Va) to Proton (Vp) as Va = Vp.
In this new interface, we also added some advanced plotting options that provide much easier way to compare these derive parameters with each other for one type of parameter (up to three graphs on the one plot panel).
More information about Wind Magnetic field, and SWE_definitive user may find at and

Time span of data sets 
 Plasma SWE definitive  1995-01-01 - 2022-10-03
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Magnetic field
IMF Magnitude Avg, nT

SWE_definitive Plasma (Original parameters)
Flow Speed, km/s
Proton Density, n/cc
Proton Temperature, K
Proton Temperature, K
Na/Np Ratio
SWE Derived parameters based on Proton density
Flow presure, nPa
Plasma Beta
Alven mach number
Magnetosonic Mach num.
SWE Plasma Derived parameters,( (based on Alpha Density = 5% Proton Density (used in OMNI)
*Flow presure, nPa
Plasma Beta
Alven mach number
Magnetosonic Mach num.
SWE Plasma Derived parameters based on Protons and Real Alpha Density
Flow presure, nPa
Plasma Beta
Alven mach number
Magnsonic Mach num.

* In the OMNI Data Base the Flow Pressure P (nPa) : = (1.67/10**6) * Np*V**2 * (1+ 4*Na/Np) for hours with non-fill Na/Np ratios and P (nPa) = (2.0/10**6) * Np*V**2 for hours with fill values for Na/Np.

*Advanced plot selections (optional)

* To show a few variables on one panel, please specify the number of variables( 1-3) in the table up[one type of variable, e.g Speed]:
        and the same number in this select box:      

Y-axis Scale: Character size(0.5-2.0):
Plot Symbol: Symbol Size(0.1-4.0): Image size (pixels) X: Y:

If you have any questions/comments about the OMNWeb Plus, contact Dr. Natalia Papitashvili,Mail Code 672, NASA/Goddard Space Flight Center, Greenbelt, MD 20771

NASA Official: Robert Candey (, Head of the Space Physics Data Facility