Context This contains the hourly mean values of the interplanetary magnetic field (IMF) and solar wind plasma parameters measured by various spacecraft near the Earth's orbit, as well as geomagnetic and solar activity indices, and energetic proton fluxes are known as OMNI2 data. **OMNI2 was created at NSSDC in 2003 as a successor to the OMNI data set first created in the mid-1970's.** You can learn about this data from https://www.ijntr.org/download_data/IJNTR02100020.pdf Time spans of various parameters are periodically extended. The documentation file at [http://omniweb.sci.gsfc.nasa.gov/html/ow_data.html][1] gives the current time spans of the following parameter groups: Magnetic field Plasma Kp index and sunspot number AE, AL, AU index Provisional AE, AL, AU index Quick look AE, AL, AU index Dst index Provisional Dst index Quick look Dst Energetic proton fluxes ap-index and f10.7_index PC(N) index Content Data gaps were filled with dummy numbers for the missing hours or entire days to make all files of equal length. The character '9' is used to fill all fields for missing data according to their format, e.g. ' 9999.9' for a field with the FORTRAN format F7.1. Note that format F7.1 below really means (1X, F6.1), etc. This directory includes two types of the ASCII flat files: OMNI2_YYYY.DAT, and OMNI_MYYYY.DAT where YYYY is a given year. The OMNIYYYY.DAT files contain the original data where the IMF and solar wind velocity vectors are presented in GSE and, for IMF, GSMcoordinate systems. The modified OMNI_MYYYY.DAT files have been created from these files with reformatting for COHOWeb compatibility and with the IMF and velocity vectors having been transformed to RTN coordinate system. --------------------------------------------------------------------------- Daily and 27-day Averages files: omni_01_av.dat; omni_27_av.dat; omni_m_daily.dat We have computed daily and 27-day average values for all the OMNI parameters in the OMNI2_YYYY.dat files, and we have computed daily averages from the OMNI_MYYYY.dat files. We have made these lower resolution averages also 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. 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 27-day 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 27-day 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 average. The ID's for the magnetic field and plasma spacecraft are set to zero, since the daily and 27-day 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 27-day 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 27-averages 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 lower standard value (13 in this case) was used. ------------------------------------------------------------------------- OMNI2_YYYY.DAT FORMAT DESCRIPTION WORD FORMAT Fill Value MEANING UNITS/COMMENTS 1 I4 Year 1963, 1964, etc. 2 I4 Decimal Day January 1 = Day 1 3 I3 Hour 0, 1,...,23 4 I5 9999 Bartels rotation number 5 I3 99 ID for IMF spacecraft See table 6 I3 99 ID for SW plasma spacecraft See table 7 I4 999 # of points in the IMF averages 8 I4 999 # of points in the plasma averages 9 F6.1 999.9 Field Magnitude Average |B| 1/N SUM |B|, nT 10 F6.1 999.9 Magnitude of Average Field Vector sqrt(Bx^2+By^2+Bz^2) 11 F6.1 999.9 Lat.Angle of Aver. Field Vector Degrees (GSE coords) 12 F6.1 999.9 Long.Angle of Aver.Field Vector Degrees (GSE coords) 13 F6.1 999.9 Bx GSE, GSM nT 14 F6.1 999.9 By GSE nT 15 F6.1 999.9 Bz GSE nT 16 F6.1 999.9 By GSM nT 17 F6 1 999.9 Bz GSM nT see http://geo.phys.spbu.ru/~tsyganenko/Geopack-2008.html developed by Drs. Nikolai Tsyganenko. 18 F6.1 999.9 sigma|B| RMS Standard Deviation in average magnitude (word 10), nT 19 F6.1 999.9 sigma B RMS Standard Deviation in field vector, nT (**) 20 F6.1 999.9 sigma Bx RMS Standard Deviation in GSE X-component average, nT 21 F6.1 999.9 sigma By RMS Standard Deviation in GSE Y-component average, nT 22 F6.1 999.9 sigma Bz RMS Standard Deviation in GSE Z-component average, nT 23 F9.0 9999999. Proton temperature Degrees, K 24 F6.1 999.9 Proton Density N/cm^3 25 F6.0 9999. Plasma (Flow) speed km/s 26 F6.1 999.9 Plasma Flow Long. Angle Degrees, quasi-GSE* 27 F6.1 999.9 Plasma Flow Lat. Angle Degrees, GSE* 28 F6.3 9.999 Na/Np Alpha/Proton ratio 29 F6.2 99.99 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 30 F9.0 9999999. sigma T Degrees, K 31 F6.1 999.9 sigma N N/cm^3 32 F6.0 9999. sigma V km/s 33 F6.1 999.9 sigma phi V Degrees 34 F6.1 999.9 sigma theta V Degrees 35 F6.3 9.999 sigma-Na/Np 36 F7.2 999.99 Electric field -[V(km/s) * Bz (nT; GSM)] * 10**-3. (mV/m) 37 F7.2 999.99 Plasma beta Beta = [(T*4.16/10**5) + 5.34] * Np / B**2 38 F6.1 999.9 Alfven mach number Ma = (V * Np**0.5) / 20 * B 39 I3 99 Kp Planetary Geomagnetic Activity Index (e.g. 3+ = 33, 6- = 57, 4 = 40, etc.) 40 I4 999 R Sunspot number (new version 2) 41 I6 99999 DST Index nT, from Kyoto 42 I5 9999 AE-index nT, from K