Flare-CME-type II events observed by Wind and/or Stereo spacecraft

Multi-vantage point DH type-II burst Catalog : Description

Detailed catalog description is published as a refereed conference IAUS 388 proceeding. The preprint of the accepted version can be found here: 

https://ui.adsabs.harvard.edu/abs/2024arXiv241000814M/abstract

Catalog and List description Catalog is divided into 2 main sections:

1. DH type II
2. Associated events: CME and flare

Section1: DH type-II

It has two sub-sections:

Properties

The basic properties of the burst as seen in the decameter-hectometric band dynamic spectrum.

Start_date, Start_time, End_date, End_time provides the time interval of the burst Freq_start and Freq_end provides the frequency extent.

The other columns are:

Detection: All spacecraft that detected the burst

Best mission: The spacecraft that detected the most long-lived burst signature with the best frequency extent and also had good quality data.

Peak_Flux: The maximum flux within 3 - 7 MHz range in the data from the best mission.

F_thresh: The typical background radio flux in the dynamic spectrum during a non-flaring period. 

Quality metrics

To identify the good data stream and event detection across spacecraft during a burst event, we define multiple quality metrics.

Data: This metric rate the data stream from each spacecraft in a scale of 0 to 2. When 0 represents data gap, 1 represent poor quality data, often due to lot of intermittent data gaps making it difficult to identify structures in the dynamic spectrum and 2 represent good data. The letter tag W stands for Wind, A for STEREO A and B for STEREO B.

Event: This metric rates the quality of the event recorded by the best data stream. An event is rated across two axes: shape (S) and intensity (I). A type-II event with a very well identifiable shape in the dynamic spectrum is given a rating of 3 while 1 represents an event whose shape is not very evident. This could be because it extends only within a narrow spectral band or because the event is in a crowded region of the dynamic spectrum where other burst types make the shape determination difficult. Similarly along the intensity axis 3 represents a bright event while 1 denotes an event with a relatively low intensity in the part of the dynamic spectrum where it is detected.

• All events with a metric SxIy, where x>1 and y>1 are generally reliable. 

Reliability: This metric rates the reliability of the radio flux estimates from 3 – 7 MHz range. The letter tag F rates the crowdedness of the dynamic spectral region or ‘Field’ where the burst is observed. If there are numerous other radio emission features in the 3 – 7 MHz band when the type-II emission was happening, then F is given a high value to indicate high crowding in the dynamic spectrum. A value of 2 is given when the crowdedness is so high that the radio flux is not reliable. 1 denote a case where it is barely reliable but the probability of the emission being admixed with other burst types is non-negligible. 0 denotes the best case where the type-II is not close to any other radio emission features and hence the flux estimate is robust. The letter tag R rates the relative flux of the burst in 3 – 7 MHz range vs the flux outside of this chosen band. A value of 1 denotes good relative flux in comparison to the typical mean flux level of the overall type-II burst. A value of 0 would mean the 3 – 7 MHz is not a good representative of the mean flux level of the type-II burst in the entire DH band spectrum.

• So F0R1 events are the events with a very reliable estimate which is representative of the overall DH burst event.

Section 2: Associated events

CME

The date, time, angular width and speed of CMEs associated with each burst are provided. The values are taken from CDAW LASCO CME catalog: https://cdaw.gsfc.nasa.gov/CME_list/

Flare

The source location, NOAA active region number, GOES X-ray flux, reconnection flux estimated using the FRED technique (Gopalswamy, N., et al., 2017) and the unsigned magnetic flux are provided. 

The Event lists

1. Full catalog: All type-II bursts with a radio flux estimate in 3 – 7 MHz band 2.
2. List 1: All events in Full catalog with good Xray flux and CME property estimates.
3. List 2: All events in List 1 with SxIy where x>1, y>1, and F0R1 quality metrics. Also those with reconnection flux estimates.