Weekly Report

(last updated 11 Sep 2025 02:03 UT)

SUBJ: ASWFC WEEKLY GEOPHYSICAL REPORT ISSUED ON 11 SEPTEMBER 2025 FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx 1. SUMMARY (02 SEPTEMBER - 10 SEPTEMBER) K indices are in UT (0-24). For conversion to local time: AEST = UT + 10 hours; ACST = UT + 9.5 hours; AWST = UT + 8 hours Australian Region* Date K-INDICES A 02 Sep 5454 3454 33 03 Sep 2222 1021 5 04 Sep 2112 2323 8 05 Sep 1112 1123 5 06 Sep 2333 4431 15 In the BOM magnetometer data for 06 Sep, a weak (20nT) impulse was observed at 1424UT. 07 Sep 0000 0012 1 08 Sep 3323 3322 12 09 Sep 2222 2224 9 10 Sep 2211 2312 6 *estimated from real time data NOTE: Indices may have been generated from data obtained in cooperation with the following organisations: Geoscience Australia, University of Newcastle Space Physics Group, Australian Government Antarctic Division and International Center for Space Weather Science and Education, Japan. G1 periods were observed on 02-Sep in the Australian regional and planetary geomagnetic field. Geomagnetic activity over the UT day was due to the arrival of a halo CME late on 01-Sep. On 06-Sep planetary conditions reached G1 due to a coronal hole wind stream, with the Australian regional field remaining at G0. 2. FORECAST (11 SEPTEMBER - 11 OCTOBER) Disturbed Periods: 15-16 Sep, 03-Oct, 06-07 Oct, 12-13 Oct. Best Quiet Periods: 12-13 Sep, 19-20 Sep , 24-25 Sep. 3. FORECAST FOR HIGH RESOLUTION AEROMAGNETIC SURVEYS Northern Australian Regions: Disturbed Periods: None. Best Quiet Periods: 11-15 Sep, 19-28 Sep, 07-11 Oct. Central Australian Regions: NA Southern Australian Regions: Disturbed Periods: 16-Sep, 18-Sep, 03-05 Oct. Best Quiet Periods: 11-14 Sep, 20-27 Sep, 30-Sep to 01-Oct, 09-11 Oct. Pc3 pulsations are high frequency (10-45 second period) variations of the Earths magnetic field. Daily pc3-indices are the daily sum of 20 minute pc3-indices for that station and have been shown to be well correlated with rejection of high resolution aeromagnetic survey flight-line data. PLEASE NOTE: Geomagnetic activity can frequently be determined by short timescale solar events that cannot be forecast a week in advance, particularly at solar maximum.