
OMNIWeb Data Documentation
Contents 
YYYY DDD  YYYY DDD 1963 331  2014 081 (IMF) 1963 331  2014 096 (Plasma) 1967 150  2014 100 (Energetic Proton Fluxes) 1963 001  2014 090 (Kp,ap indexes, Sunspot Number, f10.7 index ) 1963 001  2009 365 (Dst indices) 2010 001  2011 365 (Provisional Dst indices) 2012 001  2014 100 (Quick Look : 2009 .. Dstindex) 1963 001  1988 182 (AE, AL,AUindex) 1990 001  2014 031 (Provisional AEindex) 1975 001  2014 100 (PCn index) See below for differences among final, provisional and quick look Dst and AE indices
WORD TYPE MEANING UNITS/COMMENTS 1 I4 Year 1963,1964,1965... 2 I4 Decimal Day Day of year (Jan 1 = Day 1) 3 I3 Decimal Hour (0, 1, ...23; average for "1" is from 01:00 to 02:00) 4 I5 Bartels Rotation Number 5 I3 ID for IMF SC See table in section 6 6 I3 ID for SW Plasma SC See table in section 6 7 I4 # of fine time scale points in IMF Avgs 8 I4 # of fine time scale points in Plasma Avgs 9 F6.1 Field Magnitude Avg, <F> nT 10 F6.1 Magnitude of Average nT Field vector, <B> 11 F6.1 Lat. Angle of avg. Deg (GSE Coords) Field vector 12 F6.1 Long. Angle of avg. Deg (GSE Coords) Field vector 13 F6.1 Bx,GSE (nT) 14 F6.1 By,GSE (nT) 15 F6.1 Bz,GSE (nT) 16 F6.1 By,GSM (nT) 17 F6.1 Bz,GSM (nT) 18 F6.1 sigmaB RMS Standard deviation in avg magnitude (wd. 10), nT 19 F6.1 sigmaB RMS Standard deviation in field vector, in nT; see footnote 3 20 F6.1 sigmaBx RMS Standard deviation in GSE X comp. av, nT 21 F6.1 sigmaBy RMS Standard deviation in GSE Y comp, av, nT 22 F6.1 sigmaBz RMS standard deviation in GSE Z comp, av, nT 23 F9.0 Proton temperature Degrees Kelvin 24 F6.1 Proton density #N/cm**3 25 F6.0 Bulk speed Km/sec. 26 F6.1 Bulk flow longitude phiV, degrees. phiV increases positively/negatively from zero as the flow direction changes from being along the Xgse axis toward the +Ygse/Ygse axis; see footnote 1) 27 F6.1 Bulk flow latitude thetaV, degrees. thetaV increases positively/negatively from zero as the flow direction changes from being in the XgseYgse plane toward the +Zgse/Zgse axis; see footnote 1) 28 F6.3 Na/Np Alpha/Proton ratio 29 F6.2 Flow Pressure P (nPa) = (1.67/10**6) * Np*V**2 * (1+ 4*Na/Np) for hours with nonfill Na/Np ratios and P (nPa) = (2.0/10**6) * Np*V**2 for hours with fill values for Na/Np more 30 F9.0 sigmaT Degrees Kelvin 31 F6.1 sigman cm 3 32 F6.0 sigmaV km/sec 33 F6.1 sigmaphiV deg 34 F6.1 sigmathetaV deg 35 F6.3 sigmaratio 36 F7.2 Electric field mV/m, V(km/s) * Bz (nT; GSM) * 10**3 37 F7.2 Plasma beta Beta = [(T*4.16/10**5) + 5.34] * Np / B**2, more 38 F6.1 Alfven mach number Ma = (V * Np**0.5) / 20 * B , more 39 I3 Kp*10 3hr Kp index from NGDC (See footnote 2) 40 I4 R daily Sunspot Number from NGDC 41 I6 DST Index nT, from Kyoto 42 I5 AEindex nT, from Kyoto 43 F10.2 PROT Flux 1/(cm^2 sec ster), >1 MeV 44 F9.2 PROT Flux 1/(cm^2 sec ster), >2 MeV 45 F9.2 PROT Flux 1/(cm^2 sec ster), >4 MeV 46 F9.2 PROT Flux 1/(cm^2 sec ster), >10 MeV 47 F9.2 PROT Flux 1/(cm^2 sec ster), >30 MeV 48 F9.2 PROT Flux 1/(cm^2 sec ster), >60 MeV 49 I3 M'SPH Flux Flag = 6: No m'spheric contribution = 5: M'sph contrib in lowest energy channel = 4: M'sph c in lowest 2 chnls ... = 1: M'sph c in lowest 5 chnls = 0: M'sph c in all channels =1: Not checked for M'sph c: relevant after 88/306 (See footnote 4) 50 I4 apindex, nT, from NGDC 51 F6.1 f10.7_index, (10**22) Watts/meter sq/hertz, from NGDC adjusted to 1AU 52 F6.1 PC(N) index, Data Center for Geomagnetism, Copenhagen 53 I6 ALindex, nT, from Kyoto 54 I6 AUindex, nT, from Kyoto 55 F5.1 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 For details click HERE  FORMAT(2I4,I3,I5,2I3,2I4,14F6.1,F9.0,F6.1,F6.0,2F6.1,F6.3,F6.2, F9.0,F6.1,F6.0,2F6.1,F6.3,2F7.2,F6.1,I3,I4,I6,I5,F10.2,5F9.2,I3,I4,2F6.1,2I6,F5.1)Note that for missing data, fill values consisting of a blank followed by 9's which together constitute the Ix or Fx.y format are used.
Footnote 1:
Flowvector cartesian components in GSE coordinates
may be derived from the given speed and angles as
Vx =  V * cos(theta) * cos(phi)
Vy = + V * cos(theta) * sin(phi)
Vz = + V * sin(theta)
Footnote 2:
The standard Kp values look like 0, 0+, 1, 1, 1+, 2, ...
but are stored as Kp = 0, 3, 7, 10, 13, 17, ... in the OMNI data set.
We have mapped 0+ to 3, 1 to 7, 1 to 10, 1+ to 13, 2 to 17, etc.
Footnote 3:
SigmaB is computed as:
SQRT [(sigma(Bx))**2 + (sigma(By))**2 + (sigma(Bz))**2].
Note that this is the length of the vector formed from the standard
deviations of component averages. It is not the standard deviation in
the length of the vector formedfrom the average components.
Footnote 4:
This data set also contains fluxes of energetic protons above
1, 2, 4, 10, 30 and 60 MeV from JHU/APL instruments on IMP spacecraft
for 1967/150 to 2005/365 and fluxes of protons above 10, 30, and 60 MeV
from NOAA instruments on GOES spacecraft, spanning 2006/001 to near
current.
We have computed daily and 27day average values for all the OMNI2 parameters, and have made them accessible via OMNIWeb and via anon/ftp. Only arithmetic averaging was done. (No averaging of logarithms.) No threshold numbers of finer scale points were required. See special note on IMF angles below.
The daily averages are taken over OMNI's basic hourly values, and the 27 day averages are taken over the daily averages. The corresponding standard deviations relate only to these averagings and do not capture the variances in the higher resolution data.
The 27day averages are for discrete Bartels rotation numbers. Thus the first such average fully within 1999 spans January 9 through February 4.
The record format for the daily and 27day averages is the same as for the hourly data, although certain fields have special meanings.
The time words (year, day, hour) correspond to the first hour of the averaging period (day or 27day interval).
The ID's for the magnetic field and plasma spacecraft are set to zero, since the daily and 27day averages frequently involve data from multiple spacecraft.
The numbers of fine scale points in the plasma and field averages are counts of (1) hourly values contributing to daily averages or (2) daily values contributing to 27day averages. NOTE THAT WE HAVE NOT REQUIRED ANY MINIMUM NUMBER OF POINTS TO COMPUTE AN AVERAGE. For cases where there was only one point, the standard deviations were set to zero.
Kp was treated specially. After determining daily or 27averages from basic values such as 10 (1), 13 (1+), 17 (2), 20 (2), the average was rounded to the nearest "standard value" of Kp (i.e., 10, 13, 17, 20, ...). For cases where the average was exactly in the middle between standard values (e.g., 15), the higher standard value (17 in this case) was used.
On December 6, 2004, words 1012 (magnitude and direction angles of vectoraveraged IMF), which had been determined by simple averaging over finer scale values of these words, were replaced in OMNI by values computed from daily (or 27day) averaged IMF Cartesian components.
Spacecraft name Spacecraft ID   IMP 1 (Expl 18) 18 IMP 3 (Expl 28) 28 IMP 4 (Expl 34) 34 IMP 5 (Expl 41) 41 IMP 6 (Expl 43) 43 IMP 7 (Expl 47) 47 MAG and Plasma/MIT IMP 7 (Expl 47) 44 Plasma/LANL IMP 8 (Expl 50) 50 MAG and Plasma/MIT IMP 8 (Expl 50) 45 Plasma/LANL AIMP 1 (Expl 33) 33 AIMP 2 (Expl 35) 35 HEOS 1 and HEOS 2 1 VELA 3 3 OGO 5 5 Merged LANL VELA speeds 97 Merged LANL IMP6,7,8 T,N,V 98 ISEE 3 13 ISEE 1 11 PROGNOZ 10 10 WIND 51 ACE 71 Geotail 60
The OMNI2 data set has, since its creation, contained daily sunspot numbers and three geomagnetic activity indices: Kp (3hr), AE (1hr), and Dst (1hr). In 2009, additional indices were added: F10.7, ap, AL, AU and PCI(N). These latter indices are grouped as "ancillary parameters" near the bottom of the OMNIWeb page providing plots and list capabilities. Multihour indices are distributed into the relevant 1hour OMNI records.
Hourly AE, AL, AU and Dst values have been computed at WDC for Geomagnetism at U. Kyoto for many years now. See the preKyoto and Kyoto era histories at http://swdcwww.kugi.kyotou.ac.jp/dstae/index.html. This page, and those it links to, give full accounts of the derivations of final, provisional and quicklook AE and Dst values. Briefly, the levels are distinguished by the different levels of completeness of ground observatory network contributing to the indices and the extent of cleaning of the input data (zero level determinations, despiking, etc.) In particular, the U.Kyoto team notes that the quick look data are derived mainly for monitoring purposes, and that any use of such indices in publications should clearly indicate that the indices are quicklook. In general, there is the hope, constrained by available resources, that quick look indexes will be replaced by provisional values, and provisional values by final values. The AE and Dst values in OMNI will be extended and upgraded as those at U. Kyoto are.
The Kp, ap, F10.7 and Rz indices are explained at, and obtained electronically from, NOAA's National Geophysical Data Center. See ftp://ftp.ngdc.noaa.gov/STP/GEOMAGNETIC_DATA/INDICES/. Note footnote 2 in section 4 above, about OMNI's mapping of standard Kp values of 0, 0+, 1, 1, 1+, ..., 9, 9 to 0, 3, 7, 10, 13, ... 87, 90. Kp and ap are 3hour indices, while F10.7 and Rz are daily indices.
PC(N) is the Polar Cap Index determined from the North polar cap station at Thule, Greenland. The index is basically a 15min index that we have averaged up to hourly for inclusion in OMNI. PC(N) is taken from ftp://ftp.space.dtu.dk/WDC/indices/pcn/, World Data Center for Geomagnetism, National Space Institute, Copenhagen
The best citable reference to OMNI data is J.H. King and N.E. Papitashvili, Solar wind spatial scales in and comparisons of hourly Wind and ACE plasma and magnetic field data, J. Geophys. Res., Vol. 110, No. A2, A02209, 10.1029/2004JA010804.
If you have any questions/comments about OMNI/OMNIWEB data and service, contact: Dr. Natalia Papitashvili, Space Physics Data Facility, Mail Code 672, NASA/Goddard Space Flight Center, Greenbelt, MD 20771