June 19, 2003 To ensure continued operational monitoring of important energetic particle data, it is necessary to reassign primary/secondary designations for the GOES Space Environment Monitor (SEM) detectors. Beginning 1700 UTC on June 19, GOES 11 (105W) will become the primary satellite for protons. GOES 12 (75W) will continue as the primary satellite for magnetometer, X-ray, and electron measurements. GOES 10 (135W) will be the secondary satellite for all SEM sensors - magnetometer, X-ray, and energetic particles. Because of the degraded state of the proton data on GOES-10, its designation as the secondary source for proton data is a short-term solution. More permanent solutions have been identified and are being evaluated. Users will be notified when we define and schedule a permanent fix. May 15, 2003 See http://sec.noaa.gov/Data/ for tables of all online data at SEC, including links to non-SEC sources for older data. ======================================================================== GOES 12/10 Designated SEC's Primary/Secondary GOES Satellites GOES 8 energetic protons available again May 15 -- GOES 12 is now SEC's primary GOES satellite, except for energetic proton detectors where GOES 8 is primary. GOES 10 is the backup. The GOES 10 energetic proton detectors are showing intermittent, high noise levels in the higher energy proton channels (greater than about 80 MeV). This problem was first noticed in data taken April 26, 2003 See 2003 Proton Plots: via ftp cd /pub/plots/2003_plots/proton or http://www.sec.noaa.gov/ftpmenu/plots/2003_plots/proton.html This pattern is similar to problems experienced on the GOES 12 EPS Dome detector prior its P6 and P7 channel failures earlier this year. The loss of the P6 and P7 channels significantly impacts SEC's integral proton flux products above about 10 MeV (e.g., >10 MeV, >50 MeV, and >100 MeV). Therefore, we are acquiring energetic proton data from old GOES 8 satellite. GOES 8 differential proton flux and integral proton flux data are available in the /lists/pchan and /lists/particle directories. GOES 8 is used in Proton Flux plots. The electron processing algorithm has been modified in response to the high noise level that recently developed in the GOES 12, P6 proton channel. Caution should be used when interpreting the GOES-10 and 12 energetic proton data. One indication of the presence of high noise levels in the absence of a true enhancement in the proton flux is that all of the integral flux products above about 10 MeV (e.g., >10 MeV, >50 MeV, and >100 MeV) show nearly equal values, due to the fact that all of these derived integral fluxes are being dominated by the same high noise levels in the highest energy measurements. For detailed information see http://www.sec.noaa.gov/GOES.html ====================================================================== !!!!! NOTICE GOES Satellite Changes !!!!! !!!!! GOES 8 Ends, GOES 12 Begins !!!!! April 8, SEC stopped using GOES 8 data. GOES 10 is now SEC's primary GOES satellite, with GOES 12 the backup for magnetometer, XRS x-ray measurements, and energetic particle data. See details at http://www.sec.noaa.gov/GOES.html SEC tracks two GOES satellites and designates one as the primary and the other the secondary GOES satellite. With the switch from GOES 8 to GOES 12, the primary/secondary designations will change. GOES 10 will be the primary satellite and GOES 12 the secondary for magnetometer, XRS x-ray measurements, and energetic particles. This includes all GOES electron, proton, and alpha particle data. However, due to the failure of the P6 and P7 proton channels on GOES 12, there currently is no secondary source for these data. Users should be aware that GOES 10 data differ somewhat from GOES 8 data in two ways. First, the energetic particle detectors that are used for our operational products have a westward look direction on GOES 8 as opposed to an eastward look direction on GOES 10. Because of the different look directions, the flux measurements can differ during energetic particle events. The general flux profiles throughout particle events are similar in the GOES 8 and GOES 10 measurements; however, the GOES 10 measurements on average tend to show somewhat lower flux levels. For the largest events, the event starting times, peak flux levels, and times of the peak fluxes are similar. ======================================================================= Lists for the last 2 hours, named G10pchan_5m.txt and G12pchan_5m.txt, update every 5 minutes. Daily lists are named with the UT day of the data, e.g. 19980605_G10pchan_5m.txt. Today's list updates once an hour. Daily lists are retained on-line for 45 days. For older data see the National Geophysical Data Center Web site at http://www.ngdc.noaa.gov/stp/ See data description below. The file format follows the SEC data list convention where header lines start with either # or :. Date/times Dates are shown as year month day (2003 09 06) and "Modified Julian Day (MJD) as defined in an early SEC database. The SEC MJD for Jan 1, 2003 is 52640 The SEC MJD for Jan 1, 2004 is 53005 Time is shown as HourMin (0035) and seconds of the day (2100) Your comments and suggestions are welcome. Viola.J.Raben@noaa.gov ------------------------------------------------------------------------ GOES Proton Channel Observations Each of the GOES (Geosynchronous Operational Environmental Satellite) series of satellites carry a suite of three detector assemblies aboard: the solid state TELESCOPE, a set of large-aperture, so-called DOME detectors, and the Cerenkov/solid-state-telescope called the HEPAD (High Energy Proton and Alpha Detector), which monitor the energetic particle population at geostationary orbit. These detectors measure the flux of energetic protons from 600 keV to greater than 700 MeV in 11 discrete channels, P1 through P11, as well as monitoring the electron and alpha particle populations. The principal proton energy response of each channel is tabulated below, and the data provided are 5-minute averaged values of the 11 channels P1 through P11 respectively, as given in that table. The first 7 channels provide differential fluxes at the mean energy of the energy response interval in units of #/(cm2-s-sr-MeV), as provided by the TELESCOPE and DOME detectors. The GOES particle detectors are relatively simple solid state detectors which have their primary responses as given in the table below. As with all practical detectors, they may respond to particles which are able to penetrate their shielding or bremstrahlung produced thereby, as well as secondary particles produced by cosmic rays suffering nuclear interactions in the detector's vicinity, for example. Corrections of these secondary responses have not been applied to these differential fluxes. Both uncorrected and corrected data are available from the National Geophysical Data Center (NGDC) at http://www.ngdc.noaa.gov/stp/ It may also be pointed out that the cutoff energy at geostationary orbit is typically of the order of several MeV, and therefore the P1 response is primarily due to trapped protons of the outer zone of the magnetosphere. During moderate compressions of the magnetosphere, P2 may also 'see' magnetospherically trapped protons, while during extreme compressions (magnetopause crossings), GOES would find itself in the magnetosheath. During solar energetic particle events, P1 and P2 will respond to solar protons as well, as will all the higher energy channels, if such particles are present. ===================================================================== Channel Energy Response (MeV) Mean Energy (MeV) Detector --------------------------------------------------------------------- P1 0.8 - 4.0 2.4 TELESCOPE P2 4.0 - 9.0 6.5 " P3 9.0 - 15. 12. " P4 15. - 40. 27. DOME P5 40. - 80. 60. " P6 80. - 165. 123. " P7 165. - 500. 333. " P8 350. - 420. 385. HEPAD P9 420. - 510. 465. " P10 510. - 700. 605. " P11 >700. N/A =====================================================================