Viewing archive of Sunday, 4 July 2021

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2021 Jul 04 1239 UTC

SIDC Forecast

Solar flares

M-class flares expected (probability >=50%)

Geomagnetism

Quiet (A<20 and K<4)

Solar protons

Quiet

	10cm flux	Ap
04 Jul 2021	093	008
05 Jul 2021	091	013
06 Jul 2021	088	017

Bulletin

After yesterdays M2.7 flare the new and rapidly emerging region in the North West (NOAA 2838) produced an X1.5 flare peaking at 14:29UT, then followed by another M1 and M1.2 flare peaking at 17:03UT and 5:09UT. This marks the first X flare since September 2017, and the first of the current Solar cycle. The region is currently disappearing behind the West limb, but it may still produce flaring activity effective to Earth. The largest region remaining on disc, NOAA region 2835 is in the process of loosing its trailing spots and decreasing in size but also remains a strong candidate for further flaring activity. Both regions 2836 (unipolar) and 2837 (bipolar) are in decay. Another region is emerging near N19E45. Overall there is a significant possibility of another M flare occurring, from the region disappearing over the limb but also from region 2835 on disc.

A number of Westward CMEs are visible in SoHO/LASCO coronagraph data with the following approximate timings of first appearance in the C2 field of view: July 2: 15:36UT, July 3: 3:24UT, 7:48UT, 14:48UT and July 4 6:00UT. They are all assessed to not be geoeffective.

The greater than 10 MeV proton flux showed a slight enhancement following the X flare, but remained below 1 pfu and thus well below the 10 pfu event threshold. It is expected to be at nominal levels for the next 24 hours. The greater than 2 MeV electron flux was below the 1000 pfu event threshold. The 24h electron fluence was at normal levels and electron fluence is expected to remain at normal levels over the next days.

Solar wind has returned to nominal slow Solar wind conditions with Solar wind speed now down to 335km/s. Total magnetic field decreased from around 5nT to well below 5nT with a variable Bz. The magnetic field phi angle switched into the sector with magnetic field away from the Sun around 15UT, but since 6UT it switched back into the sector with magnetic field towards the Sun. There are no signs of the June 29 CME and it is now not expected any more. Solar wind is expected to be at nominal slow Solar wind conditions until tomorrow when enhancements may be expected associated to the small equatorial coronal hole that passed central meridian July 2.

Geomagnetic conditions were quiet to unsettled (NOAA Kp 0-1 and local K Dourbes 0-3). Geomagnetic conditions are expected to be quiet over the next 24 hours, increasing tomorrow to unsettled conditions as Solar wind enhancements are expected by that time.

Today's estimated international sunspot number (ISN): 052, based on 10 stations.

Solar indices for 03 Jul 2021

Wolf number Catania	///
10cm solar flux	094
AK Chambon La Forêt	009
AK Wingst	004
Estimated Ap	004
Estimated international sunspot number	060 - Based on 23 stations

Noticeable events summary

Provided by the Solar Influences Data analysis Center© - SIDC - Processed by SpaceWeatherLive

All times in UTC

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