Kanzelhöhe Observatory flare alerts

Introduction: The chromosphere of the Sun is an atmospheric layer above the photosphere and below the corona. As the chromosphere is outshined by the photosphere it can only be observed in some very narrow spectral lines, like Hα or CaII. At Kanzelhöhe Observatory the chromosphere is observed in Hα every day - if the local weather conditions permit - from about 8:00 to 16:00 local time.
High-cadence full-disc imaging of the Sun in the H-alpha spectral line provides an important means to identify, locate, and follow the time evolution of solar flares. H-alpha filtergrams are also well suited to identify and locate filaments erupting from the Sun, which are often associated with CMEs. The location of flares and erupting filaments provide important information whether an associated CME eruption is potentially heading toward the direction of Earth, where it may impact about 1 to 6 days later, depending on its initial speed and the solar wind conditions in the interplanetary space.

Technical Information: The Hα images are acquired by a Pulnix TM-4200GE camera with 2048 x 2048 Pixels and 4096 grey levels. The observing cadence of the H-alpha telescope system is 6 seconds. The images are checked for their quality (i.e. sharpness, clouds, intensity distribution) immediately after grabbing. If they meet specific quality criteria, they are processed by an image recognition algorithm called surya that makes use of multilabel segmentation which detects flaring regions and filaments (for further details see Pötzi, W., Veronig, A.M., Riegler, G. et al. Real-time Flare Detection in Ground-Based Hα Imaging at Kanzelhöhe Observatory. Sol Phys 290, 951–977 (2015). https://doi.org/10.1007/s11207-014-0640-5.

Limitations and caveats of the data:

• Observations are not available when the weather is bad.
• Standard observation time is between 8:00 and 16:00 local time (CET/CEST).
• Even if the panoramic view shows good weather conditions, the image quality can be too low to be processed.
• In winter the observations can start later and end earlier due to the low height of the Sun.
• The flare detection and alerting is updated every minute.
• The archive is updated every 5 minutes.
• Flares outside 60 degrees from the central meridian are not detected, due to uncertainties with area and intensity determinations near the solar limb.

Use and functionality of the product - latest:
This page shows the latest alert message sent out to the registered users. The alert message contains the start time of the flare, the importance class (see below) and the heliographic position of the flare.

Importance classes for flares
S	Subflare	area <   100 · 10-6 hemispheres
1	Importance 1	100 ≤ area <   250 · 10-6 hemispheres
2	Importance 2	250 ≤ area <   600 · 10-6 hemispheres
3	Importance 3	600 ≤ area < 1200 · 10-6 hemispheres
4	Importance 4 (3+)	area ≥ 1200 · 10-6 hemispheres
Flare Brilliance		Brightness increase
F	Faint	≥ 3 x quiet chromosphere
N	Normal	≥ 6 x quiet chromosphere
B	Brilliant	≥ 9 x quiet chromosphere

Use and functionality of the product - archive:
At first one has to select the end date of the desired period, by default the current date is set.
The period can be one of the following:

• 1 day: flares of the same day are shown
• 1 week: flares of the last 7 days are shown
• 1 month: flares since one month ago are shown
• 1 year: flares since one year ago are shown
• same month: flares of the current month are shown
• same year: flares of the current year are shown
• all data: the complete dataset is shown

For each flare following parameters are listed:

• Date: date of alert issue in the format yyyy-mm-dd
• Flare Start: start time of flare detection
• Time of alert: time when alert mail was sent out
• Flare type: see below
• Active region: active region number where the flare occurred
• Link to Alert mail: opens the alert message in a separate window
• Link to Movie: opens a flare movie in a separate window

Use and functionality of the product - email subscription:
If you want to register for the alerts, just fill in your email address, you will get a confirmation email, that also includes a link to unsubscribe. Unsubscription is also possible via this interface.

It is not possible to unsubscribe any other user!

If you are subscribed to this service you will get an alert message every time when a flare reaches at least importance class 1.

API access to UGraz/KSO Hα flare alerts

Introduction

This product can also be used via a Web API (application programming interface) for programmatically accessing the data by requesting specific URL-encoded parameters. The list of mandatory and optional variables for this specific product are included in tables 1 and 2 below:

Table 1: Mandatory parameters for API access to UGraz/KSO Hα flare alerts.

Variable	Values required for this product
pc	S107
psc	d
component	latest | archive

Table 2: Optional parameters that can be set to refine the query.

Variable	Values
dts_start, dts_end	yyyy-MM-ddTHH:mm:ssZ

Access to the latest data

To access the latest data, the “component” parameter in the address bar needs to be set to “latest”: component = latest. Available at:

https://sso.kso.ac.at/prod/API/index.php?component=latest&pc=S107&psc=d
Returns the URL of the latest KSO alert message file.

Example:

https://sso.kso.ac.at/prod/API/index.php?component=latest&pc=S107&psc=d
returns
https://sso.kso.ac.at/prod/live/halpha3/prod/sniv//logs/alert/last_kso_alert.txt

Access to archive data

To access archive data, the “component” parameter in the address bar need to be set to “archive”: component = archive. The archived images of the current day are returned as default:
https://sso.kso.ac.at/prod/API/index.php?component=archive&pc=S107&psc=d

In order to select a specific time range, the two following parameters need to be added:
"dts_start" and "dts_end" using the format yyyy-MM-ddTHH:mm:ssZ.
For example:
https://sso.kso.ac.at/prod/API/index.php?component=archive&pc=S107&psc=d&dts_start=2019-01-01T00:00:00Z&dts_end=2020-01-01T00:00:00Z
This returns a JSON containing a list of all archived flare alerts during the selected time period (here from 2019-01-01 at 00:00:00 to 2020-01-01 at 00:00:00).

The data structure of the returned JSON is as follows:

{ "[datetimestamp]": { "alerttime":[datetimestamp],"flaretype":[],"mailtext":[link]}, REPEAT "[datetimestamp]": { "alerttime":[datetimestamp],"flaretype":[],"mailtext":[link]}, REPEAT }

For example, the link above returns:

         {
        "2019-01-26T13:17:00Z":{"alerttime":"2019-01-26T13:19:00Z","flaretype":"1F","mailtext":"https://sso.kso.ac.at/prod/live/logs/2019/20190126/20190126_0003_1_1317.mail"},
        "2019-03-09T12:19:00Z":{"alerttime":"2019-03-09T12:27:00Z","flaretype":"SF","mailtext":"https://sso.kso.ac.at/prod/live/logs/2019/20190309/20190309_0004_S_1219.mail"},
        "2019-03-20T10:56:00Z":{"alerttime":"2019-03-20T10:59:00Z","flaretype":"SF","mailtext":"https://sso.kso.ac.at/prod/live/logs/2019/20190320/20190320_0009_S_1056.mail"},
        "2019-05-06T13:36:00Z":{"alerttime":"2019-05-06T13:41:00Z","flaretype":"SF","mailtext":"https://sso.kso.ac.at/prod/live/logs/2019/20190506/20190506_0007_S_1336.mail"},
        "2019-05-06T09:57:00Z":{"alerttime":"2019-05-06T09:59:00Z","flaretype":"SF","mailtext":"https://sso.kso.ac.at/prod/live/logs/2019/20190506/20190506_0007_S_0957.mail"},
        "2019-05-06T08:51:00Z":{"alerttime":"2019-05-06T08:53:00Z","flaretype":"SF","mailtext":"https://sso.kso.ac.at/prod/live/logs/2019/20190506/20190506_0006_S_0851.mail"},
        "2019-05-07T10:31:00Z":{"alerttime":"2019-05-07T11:59:00Z","flaretype":"1F","mailtext":"https://sso.kso.ac.at/prod/live/logs/2019/20190507/20190507_0018_1_1031.mail"},
        "2019-05-07T09:34:00Z":{"alerttime":"2019-05-07T09:40:00Z","flaretype":"SF","mailtext":"https://sso.kso.ac.at/prod/live/logs/2019/20190507/20190507_0005_S_0934.mail"}}
     

This web page forms part of the European Space Agency's network of space weather services and service development activities, and is supported under ESA contract number .

For further product-related information or enquiries contact helpdesk. E-mail: helpdesk.swe@esa.int

All publications and presentations using data obtained from this site should acknowledge Kanzelhöhe Observatory for Solar and Environmental Research (KSO) and The ESA Space Safety Programme.

For further information about space weather in the ESA Space Safety Programme see: www.esa.int/spaceweather

Access the ESA Space Weather Service Portal here: swe.ssa.esa.int

At Kanzelhöhe Observatory regular solar observations have been performed for more than 70 years now. The observations are carried out in Whitelight, CaII K and Hα at high cadence. Since 2013 an automatic flare detection system is in operation, that issues flare alerts within a few minutes after a flare starts. The system is improved within this project and additional features like an archive of events and images are added.

The Patrol Instrument, which comprises a set of four telescopes on a common parallactic mounting, is the heart of our observation facilities: it carries the Whitelight telescope, the CaII K telescope, the Hα telescope and a drawing device.
The 2048 x 2048 pixel sized images are recorded at a rate of 10 images per minute and 4096 grey levels. All images are immediately checked for quality and preprocessed, i.e. the FITS header is completed and jpeg images for the live display are prepared.

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