Improve descriptions of SRS data columns

[samaloney]

Via email

I’ve been looking at your revised Solar Monitor website and have the following alternative text for the explanation of the SRS information you display (the ? mark next to the table headings):

· Position. Active region heliographic position in degrees – latitude and longitude relative to the central meridian (west positive, east negative). These positions ..... · Area. Area of the sunspots in the active region expressed in millionths of the solar hemisphere corrected for foreshortening.

Hopefully you will find these an improvement (especially for the area foreshortening). It is good to see the time of day correction for longitude.

[PeterMeadows]

Just to clarify, the longitude displayed under column heading 'Position (HG Deg)' is relative to the Central Meridian and hence has positive & negative values in the range approx -90 to +90 deg. The SRS report also includes the Carrington longitude which has a values between 0 and 360 deg. Below is the NOAA definition for the SRS report:

Part I. Describes all active regions with sunspot groups:

Nmbr: An SESC region number assigned to a sunspot group during its disk passage. Note: The Solar Region Number reached 10,000 in July 2002. However, SWPC products continue to use 4-digit region numbers, with leading zeros. Location: Sunspot group location, in heliographic degrees latitude and degrees east or west from central meridian, rotated to 2400 UTC. Lo: Carrington longitude of the group. Area: Total corrected area of the group in millionths of the solar hemisphere. Z: Modified Zurich classification of the group. LL: Longitudinal extent of the group in heliographic degrees. NN: Total number of visible sunspots in the group.

etc.