Weekly Report

(last updated 29 Sep 2022 01:59 UT)

SUBJ: ASWFC WEEKLY GEOPHYSICAL REPORT ISSUED ON 29 SEPTEMBER 2022 FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx +++ CORRECTION +++ 1. SUMMARY (20 SEPTEMBER - 28 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 20 Sep 1211 1121 4 21 Sep 1112 1002 3 22 Sep 1120 1113 4 23 Sep 2122 3323 9 24 Sep 2212 2222 6 25 Sep 1112 2101 3 26 Sep 1101 1003 3 27 Sep 4534 2222 18 28 Sep 1100 0111 1 *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. Unexpected brief geomagnetic activity was observed on 27-Sep. The Australian regional geomagnetic field reached G1 for the K period 27/03-06UT. The planetary geomagnetic field Kp index reach G2 for the period 27/00-03UT. Speculatively,this disturbance may have been associated with an erupting solar prominence that was observed on 23-Sep (13-14UT) in the south west solar quadrant, with subsequent event modelling indicating an Earth miss. The prominence may have extended further back across the face of the solar disk than what was realised, resulting in a partial Earth directed component. The regional geomagnetic field was at the ASWAS G0 level on other days of the week. 2. FORECAST (29 SEPTEMBER - 29 OCTOBER) Disturbed Periods: 30 Sep to 02 Oct. Best Quiet Periods: 08-14 Oct, 16-19 Oct, 22-23 Oct, 25 Oct. 3. FORECAST FOR HIGH RESOLUTION AEROMAGNETIC SURVEYS Northern Australian Regions: Disturbed Periods: None. Best Quiet Periods: 08-25 Oct. Central Australian Regions: Mildly Disturbed: 30-Sep to 05-Oct. Best Quiet Periods: 09-23 Oct. Southern Australian Regions: Disturbed Periods: 30-Sep to 05-Oct. Best Quiet Periods: 09-23 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.