This new interface allows the OMNI users (https://omniweb.gsfc.nasa.gov/ow.html)
to calculate more accurately a few "OMNI derived parameters" that are currently included
in the OMNI2 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 https://omniweb.gsfc.nasa.gov/ftpbrowser/bow_derivation.html. 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.
Also, in addition to the Wind/SWE plasma parameters (that are used in OMNI), we now offer the Wind 3DP plasma parameters (that are cross-normalized to SWE definitive fit) and the derived parameters calculated similarly as we did for the Wind/SWE Plasma data. Note that the 3DP plasma data correlate pretty well with the SWE plasma data, but the 3DP data may have less data gaps for some intervals than the SWE plasma data.
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 four graphs on the one plot panel).
More information about Wind Magnetic field, SWE_definitive and plasma 3DP user may find at
https://cdaweb.sci.gsfc.nasa.gov/ under spacecraft "Wind".
Time span of data sets SWE definitive 1995-01-01 - 2023-10-08 Plasma 3DP 1995-01-01 - 2023-10-09Please enter your selections and then click on the Submit button.
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|