The three most recent GOES satellites – GOES-13, -14, and -15 – each have onboard an EUV Sensor (EUVS) in addition to the more familiar X-ray Sensor (XRS). EUVS has five channels (A, B, C, D, and E) that span the 50-1270A range, with the E-channel centered on the Lyman-alpha line of hydrogen at 1216A in a broadband manner similar to SDO/EVE MEGS-P, although their flare profiles are inexplicably different (see Milligan & Chamberlin 2016). Studies of Lyman-alpha emission are important from both a space weather and solar flare physics perspective as Lyman-alpha is a strong driver of changes in ionospheric composition and dynamics, as well as being a substantial radiator of flare energy from the chromosphere during the impulsive phase.

To that end, the GOES/EUVS data have recently been incorporated into the GOES workbench, which is accessible via SSWIDL, for ease of use by the heliophysics community. While GOES-13 has been taking sporadic measurements in the EUV since mid-2006, GOES-14 data are available from mid-2009 to mid-2010, and again for a few months in late 2012. GOES-15 has been much more consistent, observing the Sun continuously since early 2010, although data are currently only available up until October 2014, with more recent data becoming available soon. To access the GOES workbench, simply type IDL> goes. This will bring up the parent widget from which you can select the EUVA, EUVB, or EUVE data from the ‘Archive’ drop down menu.

Note that the Lyman-alpha profiles exhibit a dip in emission for around 4 hours each day due to geocoronal absorption by the earth’s atmosphere. For more information on GOES EUVS data, refer to https://www.ngdc.noaa.gov/stp/satellite/goes/doc/GOES_NOP_EUV_readme.pdf, and for details on how these data are incorporated into SSWIDL, along with the command line routines, please visit http://hesperia.gsfc.nasa.gov/rhessidatacenter/complementary_data/goes.html. All credit for this effort goes to Kim Tolbert at NASA/GSFC, with thanks also to Janet Machol at NOAA/NGDC for her advice and assistance.