:Issued: 2020 Jul 31 1231 UTC :Product: documentation at http://www.sidc.be/products/meu #--------------------------------------------------------------------# # DAILY BULLETIN ON SOLAR AND GEOMAGNETIC ACTIVITY from the SIDC # # (RWC Belgium) # #--------------------------------------------------------------------# SIDC URSIGRAM 00731 SIDC SOLAR BULLETIN 31 Jul 2020, 1230UT SIDC FORECAST (valid from 1230UT, 31 Jul 2020 until 02 Aug 2020) SOLAR FLARES : Quiet conditions (<50% probability of C-class flares) GEOMAGNETISM : Quiet (A<20 and K<4) SOLAR PROTONS : Quiet PREDICTIONS FOR 31 Jul 2020 10CM FLUX: 073 / AP: 003 PREDICTIONS FOR 01 Aug 2020 10CM FLUX: 073 / AP: 006 PREDICTIONS FOR 02 Aug 2020 10CM FLUX: 073 / AP: 010 COMMENT: The solar activity remained at very low levels over the past 24 hours. The two visible sunspot regions (Catania 37/N0AA-AR 2767 and N0AA-AR 2768, both classified as alpha/Hsx now) remained stable and did not produce any significant flares. The observed X-ray flux remained below B-class level. The solar activity is expected to remain at low levels over the next 24 hours. No Earth-directed Coronal Mass Ejections (CMEs) were observed in the available coronagraph imagery. The greater than 10 MeV proton flux was at background levels over the past 24 hours and is expected to remain so for the next 24 hours. The greater than 2 MeV electron flux over the past 24 hours was at background to moderate levels and is expected to remain so over the next 24 hours. Over the past 24 hours the solar wind conditions as reported by ACE and DSCOVR remained very quiet. The total interplanetary magnetic field was very weak with values between 1 nT and 6 nT. The north-south Bz component fluctuated between -5 nT and 3 nT. The Phi angle showed several long-term intervals with positive and negative orientation. In the past 24 hours the solar wind speed remained at nominal levels typical for undisturbed slow solar wind, with values gradually increasing from 312 km/s to 370 km/s. The solar wind conditions are expected to remain quiet over the next 24 hours. The geomagnetic conditions remained very quiet with maximum Kp-NOAA index equal to 1 and maximum K-Dourbes index equal to 2. The geomagnetic conditions are expected to remain quiet over the next 24 hours. The recurrent positive polarity northern coronal hole (CH 64) continues to reside on the central meridian and has now become an extension of the northern polar coronal hole. The HSS emanating from this coronal hole is expected to reach the Earth from tomorrow on, causing enhancements in the solar wind speed and possibly intervals with unsettled geomagnetic conditions. These enhancements are expected to last for a few days after their onset. TODAY'S ESTIMATED ISN : 021, BASED ON 32 STATIONS. SOLAR INDICES FOR 30 Jul 2020 WOLF NUMBER CATANIA : /// 10CM SOLAR FLUX : 073 AK CHAMBON LA FORET : 008 AK WINGST : 004 ESTIMATED AP : 004 ESTIMATED ISN : 020, BASED ON 38 STATIONS. NOTICEABLE EVENTS SUMMARY DAY BEGIN MAX END LOC XRAY OP 10CM Catania/NOAA RADIO_BURST_TYPES NONE END BT #--------------------------------------------------------------------# # Solar Influences Data analysis Center - RWC Belgium # # Royal Observatory of Belgium # # # # Website http://www.sidc.be. # # E-mail sidc-support@oma.be # # To unsubscribe http://www.sidc.be/registration/unsub.php # # # # Legal notices: # # - Intellectual Property Rights: # # http://www.astro.oma.be/common/internet/en/data-policy-en.pdf # # - Liability Disclaimer: # # http://www.astro.oma.be/common/internet/en/disclaimer-en.pdf # # - Use and processing of your personal information: # # http://www.astro.oma.be/common/internet/en/privacy-policy-en.pdf # #--------------------------------------------------------------------#
Details
The SIDC ursigram starts with the code SIDC URSIGRAM YMMDD, where
Y is the last digit of the year number,
MM is the number of the month,
DD is the day of the month.
A forecast is given on:
the global flare probability,
geomagnetic disturbances,
solar proton events.
PREDICTIONS FOR “today” : 10CM FLUX: xxx / AP: xxx
PREDICTIONS FOR “today+1”: 10CM FLUX: xxx / AP: xxx
PREDICTIONS FOR “today+2”: 10CM FLUX: xxx / AP: xxx
COMMENT
ESTIMATED ISN : xxx, based on xx stations.
where ISN stands for International Sunspot Number.
OBSERVED SOLAR INDICES FOR THE DAY BEFORE
SUNSPOT INDEX : xxx, the Wolf number observed by Catania
10CM SOLAR FLUX : xxx,
AK CHAMBON LA FORET : xxx,
AK WINGST : xxx,
ESTIMATED AP : xxx,
ESTIMATED ISN : xxx, based on xx stations.
NOTICEABLE EVENTS SUMMARY
DAY BEGIN MAX END LOC XRAY OP 10CM TYPE Catania NOAA NOTE
DAY gives the day-of-the-month.
BEGIN, MAX and END give the UT time of the different phases of the X-ray output of the event.
LOC gives the location of the event in heliographic coordinates.
XRAY gives the GOES X-ray class of the event.
OP lists the optical flare class.
10cm gives the 10.7 cm radioflux output of the event.
TYPE specifies the type of radiobursts observed.
Catania gives the Catania sunspot group number where the event happened.
NOAA is the corresponding NOAA active region number.
NOTE is the header of any other type of information, e.g. if a CME was observed associated with the event.
