# The GOES-R EUVS Model for EUV Irradiance Variability

**Authors:** E. M. B. Thiemann, F. G. Eparvier, D. Woodraska, P. C. Chamberlin, J. Machol, T. Eden, A. R. Jones, R. Meisner, S. Mueller, M. Snow, R. Viereck, T. N. Woods  
**arXiv:** [1911.09181](https://arxiv.org/abs/1911.09181)  
**Date:** 2019-11-20  
**Summary page:** https://www.summarizepaper.com/en/paper/1911.09181v1/

## Key points

- The GOES-R series of four satellites is the next generation of NOAA GOES satellites.
- They have been launched into orbit and commissioned and renamed GOES 16-19.
- These satellites are equipped with the Extreme Ultraviolet Sensors (EUVS) and X-ray Irradiance Sensors (EXIS) instrument suite which measure calibrated solar irradiance in eight lines or bands between 25 and 285 nm.
- The EUVS measurements from the EXIS instruments are used as inputs to create the EUVS Model, a solar spectral irradiance model for space weather operations that predicts irradiance in twenty-two intervals ranging from five to ten nanometers wide at a cadence of thirty seconds.
- Once fully operational, NOAA will distribute the EUVS Model irradiance with one-minute latency as a primary space weather data product.
- The algorithms used in creating the EUVS Model along with data sources, calibration methods, associated uncertainties, capabilities, and limitations are described in this paper by Thiemann et al.
- The typical model uncertainties are less than approximately five percent for variability at time-scales longer than six hours while being around twenty-five percent for solar flare-induced variability.
- The absolute uncertainties originating from calibrating instruments used to create the EUVS Model is approximately ten percent.
- Examples of model results are presented at both sub-daily and multi-year timescales to demonstrate its capabilities along with modeled example solar flare irradiances.
- The EUVS Model will be a valuable tool for space weather forecasting and monitoring providing critical information to protect infrastructure and human life in space.

## Summary

The Geostationary Operational Environmental Satellite R (GOES-R) series of four satellites is the next generation of NOAA GOES satellites. They have been launched into orbit and commissioned and renamed GOES 16-19. These satellites are equipped with the Extreme Ultraviolet Sensors (EUVS) and X-ray Irradiance Sensors (EXIS) instrument suite which measure calibrated solar irradiance in eight lines or bands between 25 and 285 nm. The EUVS measurements from the EXIS instruments are used as inputs to create the EUVS Model, a solar spectral irradiance model for space weather operations that predicts irradiance in twenty-two intervals ranging from five to ten nanometers wide at a cadence of thirty seconds. Once fully operational, NOAA will distribute the EUVS Model irradiance with one-minute latency as a primary space weather data product. This paper by Thiemann et al. describes the algorithms used in creating the EUVS Model along with data sources, calibration methods, associated uncertainties, capabilities, and limitations. The typical model uncertainties are less than approximately five percent for variability at time-scales longer than six hours while being around twenty-five percent for solar flare-induced variability. The absolute uncertainties originating from calibrating instruments used to create the EUVS Model is approximately ten percent. Examples of model results are presented at both sub-daily and multi-year timescales to demonstrate its capabilities along with modeled example solar flare irradiances. The EUVS Model will be a valuable tool for space weather forecasting and monitoring providing critical information to protect infrastructure and human life in space.