Solar
Activity

Explanation of Activity pages
The contents of each of the HELIO Solar Activity pages are described below.

Current Solar Activity page

The Summary of Current Solar Activity page brings together data from from many sources and tries to present it a way that is easy to interpret while providing the user with the means to explore further.

The currency of the information included on the page is dependant on sites that the data is sourced from. While the GOES data are available as a continuous stream, some other datasets are more sporadic. This impacts on the ability to generate some outputs that are included; some event lists may lag behind and then suddenly catch up; images may be slightly older than is desired.

Plots and Images

Location of Active Regions and Context Image

These two images show the location of active regions on the solar disk.

The plot on the left is generated by Raben Systems and shows how the active regions have performed in the recent past; a link to the key is provided. The images on the right is provided by SolarMonitor; click on the image to enter the SolarMonitor site for today and use its capabilities.

Time-series data

Plot of Soft X-ray and Proton observations from the GOES spacecraft. The GOES data are from NOAA/SWPC.

If you would like to choose a different time interval then use the HELIO CXS/QKL (GOES Light-curve) Page .

Links to additional plots

Plot of Flare Locations

The image shows the locations soft X-ray flares that occurred within the indicated time range over-plotted on a recent context image.

For more detail see below.

Coronagraph Movie

Movie showing observations from SOHO/LASCO and the matching GOES Soft X-ray light-curve. The movie is created using the CDAW Database at NASA/GSFC and includes all available images in the 24 hours before the time the page was called; the interface allows the user to adjust the time range if necessary.

The flow of data from the SOHO/LASCO coronagraph can be intermittent and it is worth checking back later if there is a data gap. If you would like to choose a different time interval, or a diferent pair of instrument panels, then use the HELIO CXS/QKL (CDAW Movie) Page .

Active Region Synoptic Plot

This synoptic plot show activity over most the solar surface – all 360°. The plot is formed of EUV images from spacecraft near the Sun-Earth line (SDO or SOHO) and from the STEREO spaceraft that are currently located on the far side of the Sun. If you look at the left part of the image – to the left of 90° – you can see the activity that should rotate onto the solar disk over the next few days.

The image was produced by the STEREO Science Center and includes STEREO SECCHI Beacon Images.

Tables

Flaring Probability by Active Region

This table shows the most recent forecast of Flaring Probability for each Active Region; the forecast is normally issued by NOAA/SWPC at ~2200 UT on previous day. The Active Regions numbers are linked into the SolarMonitor pages.

Observed Flares by Active Region

This table is an analogue of the Flaring Probability table but is generated by counting the number of flares observed during the last 4 days using Active Regions locations provided by NOAA/SWPC and flare locations determined by the SolarSoft Latest Events tool developed by Lockheed-Martin. The Active Regions numbers are linked into the SolarMonitor pages. (Note that the "Totals" column in the table includes all flares with an X-ray Class ≥A).

Recent Flares

This table is a list of recent flares determined by the SolarSoft Latest Events tool; the flare times are linked into the archived SolarSoft Latest Events pages. (Note that only flares with an X-ray Class ≥C are listed in the table)

Several years of this flare list are stored in the Heliophyiscs Event Catalogue (HEC); this can be accessed through the HELIO Interfaces page. To search the list, select the desired time range and event type "Flare", then select "GOES SXR flares from SSW Latest Events (gevloc)" and hit "Submit Search".

Recent Halo CMEs

This table lists halo Coronal Mass Ejections (CMEs) detected in SOHO.LASCO using the CACTus code (developed by ROB/SIDC). The Early/Late onset times are derived using the velocity range given in the full listing from CACTus. (Note that the Position Angle (PA) is measured counter-clockwise from North)

The complete CACTUS CME list is stored in the Heliophyiscs Event Catalogue (HEC); this can be accessed through the HELIO Interfaces page. To search the list, select the desired time range and event type "CME", then select "CACTus CME Catalogue for SOHO/LASCO" and hit "Submit Search".
 

Flare Locations page

The Flare Locations page shows the locations soft X-ray flares that occurred within the indicated time range over-plotted on a recent context image. Links to useful information are also provided.

Plot of Flare Locations

The context image is normally SDO AIA 193Å but other types are used if non are available and the software cascades down through the choices searching each over a 3 day period before going onto the next. Usually the image is sourced through the SolarMonitor site; if this site is not available then a PROBA2 SWAP image is sourced from the PROBA2 Science Centre.

All soft X-ray flares (≥A1.0) with known positions are shown; the flare locations are rotated to the time of the image and the page indicated by the known positions link shows the flares that have been included. The most recent flares (≤12 hours) are shown as red dots, 12-24 hours ago as blue dots and older ones as turquoise dots. (Note that the error associated with the longitude assigned for flares observed on/near the east limb is greater than for flares that occur on the disk. As a consequence, the flare site could appear to lead an active region when rotated to a later epoch.)

Some types of solar emission are more likely to be geo-effective if they originate from the western half to the disk (right of the central meridian).

The numbers in turquoise designate Active Regions; the numbers in red (on the left hand side of the image) indicate where old Active Regions that could be returning. Click on an Active Region if you want to see more detail; this makes a call into SolarMonitor for the selected region.

The plot is generated by HELIO; the solar images are from SolarMonitor; the flare locations are from Lockheed-Martin; Active Region locations are from NOAA/SWPC.

If you would like to produce a plot of flare locations for a different time interval, then use the HELIO CXS/QKL (Flare Locations) Page.
To examine the evolution of an active region in white light and megnetogram images, use the HELIO CXS/QKL (NAR Movie) Page.   (Note: This only works from mid-2013 onwards)

Links to Useful Information

Links to Sites hosting Observations for Today

Several solar data sites support access using a string in the URL to specify the date of interest. The links provided here have this string set to the current date.

Links to HEC Searches for events in the last 35 days

Searches of the HEC for events, etc. during the last 35 days are provided for several lists covering Flares with X-ray Class ≥M1.0, Halo CMEs, SEP events and NOAA Active Regions.

 

AR Reports page

The Active Region Reports page provides thumbnails/links to pages showing the history of every active region described in the USAF/NOAA Solar Region Summary (SRS) file for today. The pages are split into two groups, Active Regions on the disk and Active Regions due to return.

Links to information used to assemble the page are provided.

History of Active Region pages

The table shows key information for the active region for each day: the active region area, number of sunspots, Zurich-McIntosh classification, magnetic classification, and the number of C, M and X class flares that have occurred and the total number of flares, including B class flares. The TYP column flags whether the region has spots (A) or is just plage (P). Sometimes flares can be associated with a region before it has been designated by NOAA; this is can be recognized by the absence of information in all columns except flare occurrence.

For each date that is flagged as A or R, a link into SolarMonitor for the active region is provided in the right hand column. A Pop-up is provided to go directly to the magnetic field data for the active region; other channels can also be selected.

The plot is split into two panels. The top panel shows how the area (black line) of the active region area is evolving; the area corrected for foreshortening (blue line) is also plotted. The bottom panel shows the timing and size of soft X-ray flares that have occurred; the soft X-ray background is shown in red. The flare occurrence panel is updated every hour and the area plot is updated each day.

Links to information used to create the pages are also provided.

 

EUV 360° Sun page

The EUV 360 page shows the location of flares on the disk and provides a movie of the 360° Sun that allows the evolution of the active regions to be explored.

The top plot is the same as the one provided on the Flare Locations page. If you Click on an Active Region on the plot or in the right hand column it will take you to the History of Active Region page for that active region (as described above).

The movie at the bottom has been created from Stonyhurst Heliogrphic images gathered every six hours from the STEREO Science Center; each image combines EUV observations from SDO/AIA (on the Sun-Earth line) and STEREO-A/EUVI (around the far side of the Sun). The movie covers an interval of around 12 days and gives a preview of what will rotate over the east limb, as seen from Earth.


The Summary of Current Solar Activity page and Flare Location page are based on pages that were created as part of the SOARS project. The pages are now being maintained and updated by the HELIO project.
 
Created and maintained by UCL–MSSL

 
Last updated: 29th February 2016