See http://sec.noaa.gov/Data/ for tables of all online data at SEC, including links to non-SEC sources for older data. ======================================================================== December 20, 2001 ACE EPAM P1 Channel Data Suspect Data from the ACE EPAM lowest energy channel (P1) 47-65 keV are suspect since late November, following the large proton event that ended on the 24th. The cause and possible cure are being investigated by the instrument team and SEC. Look for further messages here as more information becomes available. ======================================================================== November 26, 2001 ACE SOLAR WIND DATA CONTAMINATION ENDS The solar energetic proton event that contaminated the ACE SWEPAM instrument data resulting in incorrect solar wind density, speed, and temperature values being reported by SEC on November 23 and 24 ended November 24 about 1800 UTC. To review this event see http://www.sec.noaa.gov/ftpmenu/plots/proton.html ======================================================================== November 7, 2001 ACE SOLAR WIND DATA CONTAMINATION ENDS A solar energetic proton event contaminated the ACE SWEPAM instrument data resulting in incorrect solar wind density, speed, and temperature values being reported by SEC on November 5 and 6. The contamination ended November 7 about 0300 UTC. To monitor this event see http://sec.noaa.gov/rt_plots/pro_3d.html ======================================================================== 1545 UTC Sept 27, 2001 ACE DATA RETURNS TO NORMINAL A solar energetic proton event which was contaminating the ACE SWEPAM instrument has subsided. ACE solar wind density, speed, and temperature values reported by SEC are now correct. The values were incorrect from 1602 UTC on 24 Sept until 0945 UTC on Sept 27th. The event can be seen at http://www.sec.noaa.gov/ftpdir/plots/proton/20010926_proton.gif and http://www.sec.noaa.gov/ftpdir/plots/proton/20010927_proton.gif ======================================================================== See http://sec.noaa.gov/Data/ for tables of all online data at SEC, including links to non-SEC sources for older data. ======================================================================== July 27, 2001 ACE SPACECRAFT MANEUVER COMPLETED NASA performed a Z-axes maneuver, to keep the Spacecraft in L1 orbit. ACE Real-Time Solar Wind data was unavailable from 1534 UTC July 23th until 1825 UTC July 26, 2001. ======================================================================== July 26, 2000 ACE EPAM Data Lists Header Line Changes The ACE EPAM 5-min data lists, had incorrect Differential Proton Flux ranges. The header lines were changed beginning with the 26 July 2000 file. CORRECTED: # -- Differential Flux -------------------------- # UT Date Time ------------------ Protons keV ---------------- # YR MO DA HHMM 47-65 112-187 310-580 761-1220 1060-1910 INCORRECT: # -- Differential Flux -------------------------- # UT Date Time ------------------ Protons keV ---------------- # YR MO DA HHMM 56-78 130-214 337-594 761-1220 1073-1802 ======================================================================== July 28, 1998 The EPAM 761-1220 MeV Proton algorithm was adjusted at 7/28 1600UT. There was factor of 3 decrease which matches expected values. ======================================================================== STATUS REPORTS 4/3/98 Update on quality of ACE RTSW data sets MAG: All data nominal SWEPAM: All data nominal. When the velocity of the solar wind falls to low values the current algorithm will often set a flag indicating a problem exists. SEC flags the data in the data base and does not plot the data on the web site. The end result is a number of missing data at the one minute cadence. EPAM: All differential flux channels nominal, except for W1. This channel is impacted by above normal temperatures on ACE. APL is looking at this issue. The only impact is the anisotropy index is not valid. The energy range of this channel is covered by the other existing channels. SIS: Both integral channels nominal. Integral flux is at background until a large event is detected Update on tracking: RAL, NASA, and AFSCN are fully operational. CRL is down for antenna repair and is expected up in two months. AFSCN has added extra tracking coverage during the time period normally covered by CRL. Occasionally short dropouts occur during a tracking pass, usually due to data transmission problems. Bad data records are received during some tracking passes. Software eliminates most of the problem data, but not all problem data. ========================================================================= 2/9/98 - A software solution to the SWEPAM instrument problem was installed on 2/5. Density, Bulk Speed and Ion Temperature data now appear nominal. 2/2/98 - The Spacecraft Location files will not be available until March. 2/2/98 - The Magnetometer data is still in spacecraft coordinates (RTN). Will not be switched to GSM coordinates in March. 2/2/98 - Lists of hourly average will not be available until March. 2/2/98 - The limits shown below for Mag component magnitude, SWEPAM bulk speed, SWEPAM X vector velocity, and Xgse location were corrected 2/2/98. 1/21/98 - Operational ACE data lists began running. Your comments and suggestions are welcome. Thank you, Viola Raben vraben@sec.noaa.gov ******************************************************************************** ******************************************************************************** Real-Time Solar Wind (RTSW) data from the Advanced Composition Explorer (ACE) spacecraft are made available by the Space Envirnoment Center (SEC) as updating data lists and plots. The plots are available through the SEC Web site at URL: http://sec.noaa.gov. Follow the link to "Real-time Solar Wind Data". --- ACE RTSW Instruments Average Intervals MAG - Magnetometer 1-min and 1-hour SWEPAM - Solar Wind Electron Proton Alpha Monitor 1-min and 1-hour EPAM - Electron Proton and Alpha Monitor 5-min and 1-hour SIS - Solar Isotope Spectrometer 5-min and 1-hour All data lists are ASCII text files with a standard SEC data list format. There are two lists for each of the four ACE instruments; a 2-hour list and a daily list. The 2-hour lists contain the most recent 2 hours of data from the instrument and are updated in near-real-time. The Magnetometer and SWEPAM data is available as 1-min averages and these lists are updated once a minute. The EPAM and SIS data is available as 5-minute averages and the lists are updated once every 5 minutes. The Daily lists for all instruments are updated once a hour beginning at 0101UT daily. --- Filenaming Conventions The filenames for the 2 hour lists do not change. Users retrieving data frequently usually ftp these short files because the filenames do not change. ace_mag_1m.txt ace_swepam_1m.txt ace_epam_5m.txt ace_sis_5m.txt The daily lists have the UT date prefixed to the basic filename. For example 19971201_ace_mag_1m.txt is the filename for Mag data on Dec 1, 1997. 19971201_ace_mag_1m.txt 19971201_ace_swepam_1m.txt 19971201_ace_epam_5m.txt 19971201_ace_sis_5m.txt --- Retention Daily files are retained for 10 days. --- File format o The first line begins with :Product: followed by the file name. o The second line begins with :Issued: followed by the date/time the file was created. o The next lines begin with # and contains header information about the list. The number of header lines is NOT guarenteed to be fixed. o The lines following the header (#) lines are data records, there are no header lines after the data begins. o The file ends with the last data record. o There is a data record for each time interval. For example, a completed daily 5-min file contains 288 data records-- one for each 5 minute interval in the day. When no data are available there is a record containing missing data values for that interval. o Fields within each record are delimitated by white space. Records are written with a formatted write statement so the field widths do not change. However, SEC reserves the right the change the format as needed. --- Valid Data The header lines on each list identify the data values, units, and missing data values. The range of valid values are shown below: Date/time fields for all data lists Valid Range Description Format min / max -------------------------------------------------------------- UT Year Integer 1998 - UT Month Integer 1 / 12 UT Day Integer 1 / 31 UT Time - Time at the beginning of the averaging interval HH - Hour Integer 00 / 23 MM - Minutes Integer 00 / 59 Modified UT Julian Day Integer 1/1/98 was 50814 Seconds of UT Day Integer 0 / 86340 Status Flags Status fields for all instruments are a one digit integer from 0 through 9 where 0 = nominal data, 9 = no data, and 1-8 indicate bad data. More specifically: 0 = Data values a nominal 1 = SWEPAM data flag non-zero 2 = Spacecraft attitude may be in error (following a maneuver) 3 = SWEPAM mode is bad 4 = The magnetometer flip bit is on, data are not processed 5 = The magnetometer is in calibration mode, data are not processed during calibration 6 = Some values in the data record were out of their valid range, unable to to process the data 7 = Some values in the data record were missing, unable to process the data 8 = The data record was incomplete, unable to process the data 9 = No data were received at SEC, usually because no site was tracking ACE -------------------------------------------------------------------------------- MAG - Magnetometer Description Format Units min/max IMF X-component in GSM coordinates Float nT -200.0 / 200.0 IMF Y-component in GSM coordinates Float nT -200.0 / 200.0 IMF Z-component in GSM coordinates Float nT -200.0 / 200.0 IMF component magnitude Float nT 0.0 / 200.0 IMF latitude in GSM coordinates Float degrees -90.0 / 90.0 IMF longitude in GSM coordinates Float degrees 0.0 / 360.0 -------------------------------------------------------------------------------- SWEPAM - Solar Wind Electron Proton Alpha Monitor Description Format Units min/max Solar wind proton density Float p/cc 0.0 / 200.0 Solar wind bulk speed Float km/s 200.0 / 2000.0 Solar wind ion temperature Float degrees K 1.00E4 / 1.00E7 Solar wind vector velocity in GSE x-direction Float km/s -2000.0 / -200.0 Solar wind vector velocity in GSE y-direction Float km/s -200.0 / 200.0 Solar wind vector velocity in GSE Z-direction Float km/s -200.0 / 200.0 -------------------------------------------------------------------------------- EPAM - Electron Proton and Alpha Monitor Description Format Units min/max Differential electron flux 38-53 keV Float p/(cm2-sec-ster-MeV) 0.00 / 1.0E8 Differential electron flux 175-315 keV Float p/(cm2-sec-ster-MeV) 0.00 / 1.0E7 Differential proton flux 47-65 keV Float p/(cm2-sec-ster-MeV) 0.00 / 1.0E8 Differential proton flux 112-187 keV Float p/(cm2-sec-ster-MeV) 0.00 / 1.0E7 Differential proton flux 310-580 keV Float p/(cm2-sec-ster-MeV) 0.00 / 1.0E7 Differential proton flux 1060-1910 keV Float p/(cm2-sec-ster-MeV) 0.00 / 1.0E6 W1 (480-966 keV proton flux) Float p/(cm2-sec-ster-MeV) 0.00 / 1.0E7 Anisotropy Index Float 0.0 / 2.0 -------------------------------------------------------------------------------- SIS - Solar Isotope Spectrometer Integral Flux of High-energy Solar Protons Description Format Units min/max Integral proton flux at >10 MeV Float p/(cm2-sec-ster) 0.00 / 1.00E5 Integral proton flux at >30 MeV Float p/(cm2-sec-ster) >0.00 / 1.00E5 -------------------------------------------------------------------------------- ACE Spacecraft Location Description Format Units min/max X position in GSE coordinate (Earth radii) Float Re 0.0 / 300.0 Y position in GSE coordinate (Earth radii) Float Re -200.0 / 200.0 Z position in GSE coordinate (Earth radii) Float Re -200.0 / 200.0