https://spdf.gsfc.nasa.gov/pub/data/omni/high_res_omni/modified/hro_modified_format.txt The Modified (Level-3) High Resolution OMNI data files are made in the same format as the files located in the upper leve directory (../hroformat.txt). There are three differences should be noted in the new files comparing to the upper-level files: 1. In the new, modified Level-3 OMNI data files we used the Wind/SWE plasma definitive data rather than the Wind/SWE plasma KP-despiked data. Using the definitive data give us possibility to include the Alpha/Proton Density Ratio and use more accurate plasma parameters. However, the time coverage in the new OMNI data was decreased by 2-10% - see the table at the bottom of this desciption. See https://omniweb.sci.gsfc.nasa.gov/ftpbrowser/wind_pla_def_kp_norm.html for detail comparison 1-min. SWE definitive and cross-normalized SWE_KP data sets. 2. To keep the records length to be the same as in the old data set we replaced the PCN-index (word #45 ) in the records with the new Alpha/Proton Dendity Ratio parameter. 3. The latest date for these new data usualy behind of the OMNI based on SWE_KP data (upper level directory) The format for 1-min and 5-min* modified (Level-3) OMNI data sets is the follwoing: Word Format Fill val. 1 Year I4 1995 ... 2006 2 Day I4 1 ... 365 or 366 3 Hour I3 0 ... 23 4 Minute I3 0 ... 59 at start of average 5 ID for IMF spacecraft I3 99 See footnote D below 6 ID for SW Plasma spacecraft I3 99 See footnote D below 7 # of points in IMF averages I4 999 8 # of points in Plasma averages I4 999 9 Percent interp I4 999 See footnote A below 10 Timeshift, sec I7 999999 11 RMS, Timeshift I7 999999 12 RMS, Phase front normal F6.2 99.99 See Footnotes E, F below 13 Time btwn observations, sec I7 9999999 DBOT1, See Footnote C below 14 Field magnitude average, nT F8.2 9999.99 15 Bx, nT (GSE, GSM) F8.2 9999.99 16 By, nT (GSE) F8.2 9999.99 17 Bz, nT (GSE) F8.2 9999.99 18 By, nT (GSM) F8.2 9999.99 Determined from post-shift GSE components 19 Bz, nT (GSM) F8.2 9999.99 Determined from post-shift GSE components See footnote "gsm" below 20 RMS SD B scalar, nT F8.2 9999.99 21 RMS SD field vector, nT F8.2 9999.99 See footnote E below 22 Flow speed, km/s F8.1 23 Vx Velocity, km/s, GSE F8.1 99999.9 24 Vy Velocity, km/s, GSE F8.1 99999.9 25 Vz Velocity, km/s, GSE F8.1 99999.9 26 Proton Density, n/cc F7.2 999.99 27 Temperature, K F9.0 9999999. 28 Flow pressure, nPa F6.2 99.99 See footnote G below 29 Electric field, mV/m F7.2 999.99 See footnote G below 30 Plasma beta F7.2 999.99 See footnote G below 31 Alfven mach number F6.1 999.9 See footnote G below 32 X(s/c), GSE, Re F8.2 9999.99 33 Y(s/c), GSE, Re F8.2 9999.99 34 Z(s/c), GSE, Re F8.2 9999.99 35 BSN location, Xgse, Re F8.2 9999.99 BSN = bow shock nose 36 BSN location, Ygse, Re F8.2 9999.99 36 BSN location, Zgse, Re F8.2 9999.99 Ancilary Data 38 AE-index, nT I6 99999 See footnote H below 39 AL-index, nT I6 99999 See footnote H below 40 AU-index, nT I6 99999 See footnote H below 41 SYM/D index, nT I6 99999 See footnote H below 42 SYM/H index, nT I6 99999 See footnote H below 43 ASY/D index, nT I6 99999 See footnote H below 44 ASY/H index, nT I6 99999 See footnote H below 45 Na/Np Ratio F7.3 9.999 See footnote I below 46 Magnetosonic mach number F5.1 99.9 See Footnote K below The data may be read with the format statement (2I4,4I3,3I4,2I7,F6.2,I7, 8F8.2,4F8.1,F7.2,F9.0,F6.2,2F7.2,F6.1,6F8.2,7I6,F7.3, F5.1) * Note For 5-min data we added fluxes from GOES at the end of each record in format: Proton Flux >10 MeV, 1/(cm**2-sec-ster) F9.2 99999.99 See footnote J below Proton Flux >30 MeV, 1/(cm**2-sec-ster) F9.2 99999.99 Proton Flux >60 MeV, 1/(cm**2-sec-ster) F9.2 99999.99 Footnote A: Percent interp: The percent (0-100) of the points contributing to the 1-min magnetic field averages whose phase front normal (PFN) was interpolated because neither the MVAB-0 nor Cross Product shift techniques yielded a PFN that satisfied its respective tests (see detailed documentation for these). Footnote C: The DBOT (Duration Between Observing Times) words: For a given record, we take the 1-min average time shift and estimate, using the solar wind velocity and the location of the observing spacecraft, the time at which the corresponding observation would have been made at the spacecraft. Then we take the difference between this time and the corresponding time of the preceding 1-min record and define this as DBOT1. This difference would be one minute in the absence of PFN and/or flow velocity variations. When this difference becomes negative, we have apparent out-of- sequence arrivals of phase planes. That is, if plane A is observed before plane B at the spacecraft, plane B is predicted to arrive at the target before plane A. Searching for negative DBOT enables finding of such cases. DBOT2 is like DBOT1 except that the observation time for the current 1-min record is compared to the latest (most time- advanced) previous observation time and not to the observation time of the previous record. Use of DBOT2 helps to find extended intervals of out-of-sequence arrivals. We do not capture out-of-sequence-arrival information at 15-s resolution but only at 1-min resolution. The standard deviation in the 1-min averaged time shifts may be used to help find cases of out-of-sequence 15-s data. Footnote gsm: The computation of standard By and Bz, GSM is taken from the GEOPACK-2008 at http://geo.phys.spbu.ru/~tsyganenko/Geopack-2008.html) software package developed by Drs. Nikolai Tsyganenko. Footnote D: The following spacecraft ID's are used: ACE 71 Geotail 60 IMP 8 50 Wind 52 ( we use definitive plasma data) Footnote E: Note that standard deviations for the two vectors are given as the square roots of the sum of squares of the standard deviations in the component averages. The component averages are given in the records but not their individual standard deviations. Footnote F: There are no phase front normal standard deviations in the 5-min records. This word has fill (99.99) for such records. Footnote G: Derived parameters are obtained from the following equations. Flow pressure = (2*10**-6)*Np*Vp**2 nPa (Np in cm**-3, Vp in km/s, subscript "p" for "proton") Electric field = -V(km/s) * Bz (nT; GSM) * 10**-3 Plasma beta = [(T*4.16/10**5) + 5.34] * Np / B**2 (B in nT) Alfven Mach number = (V * Np**0.5) / (20 * B) For details on these, see http://omniweb.sci.gsfc.nasa.gov/ftpbrowser/bow_derivation.html Footnote H: Provisional high res. Indices where taken from World Data Center for Geomagnetism, Kyoto: http://swdcwww.kugi.kyoto-u.ac.jp/aeasy/ Footnote I: The new parameter Na/Np Ratio is included using Wind SWE definitive data. Footnote J: Proton fluxes from GOES were taken from http://satdat.ngdc.noaa.gov/sem/goes/data/new_avg/ Footnote K: Magnetosonic Mach Number = V/Magnetosonic_speed Magnetosonic speed = [(sound speed)**2 + (Alfv speed)**2]**0.5 The Alfven speed = 20. * B / N**0.5 The sound speed = 0.12 * [T + 1.28*10**5]**0.5 About Magnetosonic speed check https://omniweb.sci.gsfc.nasa.gov/bow_derivation1.html also ________________________________________________________________________________________ the table below shows decreasing real SWE plasma parameters in high res.OMNI when definitive data is used rather than SWE KP data ------------------------------------------------------------------------------- YEAR % of decreasing ------------------------ 1995 1.6 1996 3.2 1997 7.4 1998 3.0 1999 2.5 2000 2.2 2001 3.1 2002 3.4 2003 2.4 2004 2.1 2005 4.8 2006 7.0 2007 5.4 2008 2.7 2009 0.2 2010 9.9 2011 5.3 2012 2.8 2013 10.1 2014 9.4 2015 3.1 2016 3.7 2017 2.5 2018 2.0 2019 2.2 2020 2.8 2021 4.1 2022 7.7 2023 11.6 --------------------- Related data and directories: SPDF Data and Orbits Services ------------------------------------------- Acknowledgement: Use of these data in publications should be accompanied by acknowledgements of the Space Physics Data Facility(SPDF) and ------------------------------------------------------------------------- SPDF Contact: Natalia Papitashvili --------------------------------------------------------------------------- Authorizing NASA Official: R.M. Candey, Head, SPDF, NASA Goddard Space Flight Center e-mail: Robert.m.candey@nasa.gov -----------------------------------------------------------------