Weekly Report

(last updated 04 Dec 2025 01:29 UT)

SUBJ: ASWFC WEEKLY GEOPHYSICAL REPORT ISSUED ON 04 DECEMBER 2025 FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx 1. SUMMARY (25 NOVEMBER - 03 DECEMBER) 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 25 Nov 3335 4433 22 26 Nov 3333 5322 17 27 Nov 2233 4323 13 In the BOM magnetometer data for 27 Nov, a weak (18nT) impulse was observed at 1200UT. 28 Nov 3234 3332 14 29 Nov 2333 3323 13 30 Nov 3222 1222 7 01 Dec 2221 3211 6 02 Dec 2221 1222 6 03 Dec 1123 5445 22 *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. In the Australian regional field G1 periods were observed on 25-Nov, 26-Nov and 03-Dec in association with coronal hole high speed solar wind streams. Planetary G3 conditions were observed 03/1800-2100UT. Planetary G1 conditions were observed on 25 Nov and 27-Nov. 2. FORECAST (04 DECEMBER - 03 JANUARY) Disturbed Periods: 4-5 Dec, 21-23 Dec, 30 Dec - 01 Jan. Best Quiet Periods: 8-12 Dec, 14-17 Dec, 19-Dec, 28-Dec. 3. FORECAST FOR HIGH RESOLUTION AEROMAGNETIC SURVEYS Northern Australian Regions: Mildly Disturbed Periods: 22-23 Dec Best Quiet Periods: 8-11 Dec, 15-20 Dec 28-30 Dec Central Australian Regions: Disturbed Periods: 22-23 Dec Mildly disturbed: 04-05 Dec, 12-Dec, 21-Dec, 24-26 Dec Best Quiet Periods: 8-10 Dec, 16-19 Dec and 29-Dec. Southern Australian Regions: Disturbed Periods: 04-05 Dec, 12-13 Dec, 21-27 Dec. Best Quiet Periods: 9-10 Dec, 16-19 Dec and 29-Dec. 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.