:Product: 19980828SGAS.txt :Issued: 1998 Aug 28 0245 UTC # Prepared jointly by the U.S. Dept. of Commerce, NOAA, # Space Environment Center and the U.S. Air Force. # JOINT USAF/NOAA SOLAR AND GEOPHYSICAL ACTIVITY SUMMARY SGAS NUMBER 240 ISSUED AT 0245Z ON 28 AUG 1998 THIS REPORT IS COMPILED FROM DATA RECEIVED AT SWO ON 27 AUG A. ENERGETIC EVENTS BEGIN MAX END RGN LOC XRAY OP 245MHZ 10CM SWEEP NONE B. PROTON EVENTS: THE GREATER THAN 10 MEV PROTON FLUXES HAVE REMAINED ABOVE EVENT THRESHOLDS THROUGHOUT 27 AUGUST. THE GREATER THAN 100 MEV PROTON EVENT WAS DECLARED OVER AT 26/2050 UT. ENERGETIC ELECTRONS FLUXES GREATER THAN 2 MEV, AS MEASURED BY THE GOES SATELLITE AT GEOSYNCHRONOUS ORBIT, HAD DECREASED TO ABOUT 10 PFU EARLY ON 27 AUG AFTER PREVIOUSLY REACHING NEAR THE SEC ALERT THRESHOLD OF 1000 PFU ON PREVIOUS DAYS. SINCE 27/0900 UT, THE FLUXES HAVE BEEN INCREASING. C. GEOMAGNETIC ACTIVITY SUMMARY: THE GEOMAGNETIC FIELD HAS BEEN AT MAJOR STORM TO SEVERE STORM LEVELS. MID-LATITUDE K-INDICES REACHED 7 AND 8 BETWEEN 27/0300 UT AND 27/1200 UT. THE FORBUSH DECREASE THAT BEGAN LATE ON 25 AUGUST CONTINUES, WITH NEUTRON MONITOR COUNTING RATES FROM THULE DEPRESSED BY ABOUT 6 PERCENT TODAY. D. STRATWARM: NONE. E. DAILY INDICES: (REAL-TIME PRELIMINARY/ESTIMATED VALUES) 10 CM 135 SSN 153 AFR/AP 080/112 X-RAY BACKGROUND B3.0 DAILY PROTON FLUENCE (FLUX ACCUMULATION OVER 24 HRS) GT 1 MEV 9.0E+07 GT 10 MEV 2.8E+06 P/(CM2-STER-DAY) (GOES-8 SATELLITE SYNCHRONOUS ORBIT W75 DEGREES) DAILY ELECTRON FLUENCE GT 2 MEV 1.70E+07 E/(CM2-STER-DAY) (GOES-8 SATELLITE SYNCHRONOUS ORBIT W75 DEGREES) 3 HOUR K-INDICES: BOULDER 7 8 6 6 5 4 3 3 PLANETARY 7 7 8 7 7 6 6 5 F. COMMENTS: NONE.