Weekly Report

(last updated 09 Oct 2025 01:18 UT)

SUBJ: ASWFC WEEKLY GEOPHYSICAL REPORT ISSUED ON 09 OCTOBER 2025 FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx 1. SUMMARY (30 SEPTEMBER - 08 OCTOBER) 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 30 Sep 3445 5445 33 01 Oct 3343 5343 22 02 Oct 4435 3233 21 03 Oct 3344 3332 17 04 Oct 2334 4321 14 05 Oct 2222 2102 5 06 Oct 1111 2111 3 07 Oct 2223 3322 10 08 Oct 2222 4211 8 *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. The Earth entered a coronal hole high speed wind stream on 30-Sep and a prolonged period of moderately elevated regional geomagnetic activity was observed 30-Sep to 03-Oct with the Australian regional field reaching G1 on 30-Sep, 01-Oct and 02 Oct. Planetary geomagnetic conditions were G3 on 30-Sep and on 02-Oct, G2 on 01-Oct, and G1 on 03-Oct. 2. FORECAST (09 OCTOBER - 08 NOVEMBER) Disturbed Periods: 12-13 Oct, 26-27-Oct, 30-Oct. Best Quiet Periods: 15-20 Oct, 23-24 Oct, 6 Nov. 3. FORECAST FOR HIGH RESOLUTION AEROMAGNETIC SURVEYS Northern Australian Regions: Mildly Disturbed Periods: 28-30 Oct Best Quiet Periods: 16-19 Oct, 22-27 Oct, 02-07 Nov Central Australian Regions: Mildly Disturbed Periods: 12-Oct, 14-15 Oct, 20-21 Oct Disturbed: 13-Oct, 28-30 oct Best Quiet Periods: 16-19 Oct, 23-26 Oct, 03-06 Nov. Southern Australian Regions: Disturbed Periods: 12-15 Oct, 20-21 Oct, 28-31 Oct. Best Quiet Periods: 16-19 Oct, 23-26 Oct, 03-06 Nov. 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.