The GOLD mission and opportunities to enhance understanding

The GOLD mission, and opportunities to enhance understanding of thermosphere/ionosphere system through collaboration Alan Burns, Richard Eastes*, Bill Mc. Clintock, Dave Anderson, Laila Andersson, Mihail Codrescu, John Correira, Rob Daniels, Scott England, Scott Evans, Jerry Lumpe, Andrey Krymonos, Carlos Martinis, Dave Rusch, Stan Solomon, Tom Woods, Jens Oberheide, and Scott Budzein.

GOLD Status • Launched on SES-14 - Jan 25, 2018 - Ariane 5 rocket from French Guiana • Detector doors opened - Jan 29, 2018 • Transfer to GEO in progress • Operations begin October 2018 GOLD Launch (Jan 25 th, 2018)

Where is GOLD today! Epoch (UTC): Eccentricity: inclination: perigee height: apogee height: 21 June 0. 1021118 2. 0499° 31470 km 40079 km https: //www. heavens-above. com/

GOLD Science is Framed by 4 Questions Science Question 1. How do geomagnetic storms alter the temperature and composition structure of thermosphere? Science Question 2. What is the global-scale response of thermosphere to solar extremeultraviolet variability? Science Question 3. How significant are the effects of atmospheric waves and tides propagating from below on thermospheric temperature structure? Science Question 4. How does the nighttime equatorial ionosphere influence the formation and evolution of equatorial plasma density irregularities?

Daily Science Operations • Commands are uploaded to the GOLD instrument on a weekly basis - Uploads contain absolute and relative time sequences

L 2 Data Products Validation Data Description [units] Validation Approach Lead Level 2 O/N 2 Neutral composition. Ratio of O to N 2 vertical column density [dimensionless] Coincident ICON O/N 2; coincident GUVI and SSUSI data if available Tdisk Thermospheric neutral temperature [K] Coincident ISR data and cross comparison with Texo S. Solomon QEUV Solar EUV flux proxy [m. W/m 2] Coincident Solar disk obs. S. Evans Texo Neutral exospheric temperature [K] O 2 number density profile [mol/cm 3] Nmax Peak electron density [electrons/cm 3] BOI, N 2 Emission brightness [Rayleighs] Coincident data from ICON; coincident GUVI and SSUSI data if available Comparison with historical data and cross comparison with ICON measurements of N 2 limb profiles Coincident data from Jicamarca ISR and ionosondes; COSMIC II, if available Coincident satellite data (ICON, GUVI, SSUSI, etc. ) J. Correira S. Evans J. Lumpe C. Martinis W. Mc. Clintock

Data Products versus Science Requirements Data Product Notes/Constraints Requirement Realized* Images of Temperature 60 min Cadence 250 x 250 km 2 Resolution Precision – 55 K 27 K Images of O/N 2 Radiance Ratio 30 min Cadence 250 x 250 km 2 Resolution Precision – 10 % 6. 5 % Exospheric Temperature 100 km Vertical Resolution on Limb Precision – 40 K 22 K O 2 Column Density at 160 km Precision – 10 % 2% Vertical Resolution – 10 km 5. 5 km Nmax F 2 220 x 220 km 2 Resolution Precision – 10 % 5. 7 % *Realized values from retrievals using simulated data

GOLD Field of Regard Global C band beam

O/N 2 and Ground Stations (2006 AGU storm) * ISRs ^ Ionosondes in Umass Lowell Database with 2018 data + GOLD location

Daytime Measurements of Nm. F 2 and O/N 2 over Port Stanley Ionosonde Observations in Daylight * * * * * * + + + * GOLD measurements of O/N 2 over Port Stanley + + + + + Satellite in LEO measurements of O/N 2 over Port Stanley # …an unprecedented opportunity to compare composition with electron density and to provide a global context for these comparisons

• The SES-14 satellite with GOLD on board is almost in its geostationary orbit • GOLD is scheduled to provide regular data from October • GOLD provides an unprecedented opportunity for comparisons with ground- and other space-based observations

GOLD Airglow Simulation (Solomon)

Forcing of thethe Thermosphere-Ionosphere Forcing Upper Atmosphere Knipp, 2004