Composite Solar Lyman-alpha


Date Range: to


Full dataset   Displayed range

Access this data programmatically

The composite Lyman-alpha time series includes measurements from multiple instruments and models to construct a long time series history of the bright solar H I 121.6 nm emission. Measurements are used whenever they are available and are indicated by the 'type' variable with the following convention:

type =
  • 1 for UARS SOLSTICE version 18 data
  • 2 for SME data scaled to UARS SOLSTICE level
  • 3 for AE-E data scaled to UARS SOLSTICE level
  • 4 for model using NOAA SBUV Mg C/W index
  • 5 for model using square root of F10.7
  • 6 for TIMED SEE data version 11 calibrated to UARS SOLSTICE level
  • 7 for SORCE SOLSTICE version 13 calibrated to UARS SOLSTICE level
  • 8 for SDO EVE version 5 calibrated to UARS SOLSTICE level

The values are all scaled to match the UARS reference level as discussed by Woods et al. [JGR 2000]. The measured irradiance from SORCE SOLSTICE and SDO EVE are divided by a simple scale factor of 1.04 to match the UARS reference level. The composite time series begins with a model from the first F10.7 cm radio flux measurements from 1947 and continues to date. Since TIMED SEE, SORCE SOLSTICE and SDO EVE have significant overlap, the preference is always given to SORCE SOLSTICE, then SDO EVE, then TIMED SEE. Version 3 of this product include SDO EVE data for the first time.

Note that the 2001-2003 time frame is filled with model results due to some degradation issues with overlapping UARS and TIMED measurements.

Please see the 'API' tab for more download information and options.

LISIRD

Example URLs that would provide all of the data follows: The third column identifies the data source 'type', as described under the 'About' tab.