Introduction to special section on Aura Validation

Abstract

Aura, the last of the large EOS observatories, was launched on 15 July 2004 and has now been operating for several years. Aura is designed to make comprehensive stratospheric, mesospheric, and tropospheric constituent measurements from its four instruments HIRDLS, MLS, OMI, and TES. All of the instruments are performing well and observations of stratospheric and tropospheric trace gases and aerosols are revolutionizing our understanding of stratospheric chemistry and transport processes, ozone depletion, air quality, and the hydrological cycle. In this special section, the instrument teams and collaborators report on the validation of the released Aura data products.

Evidence for energetic particle precipitation and quasi-biennial oscillation modulations of the Antarctic NO<sub>2</sub> springtime stratospheric column from OMI observations

“…In our analysis, we use data from latitudes poleward of 50 • S. Note that all latitudes are geographic latitudes in the following. Aura is in a Sun-synchronous orbit in the "A-train" constellation (orbital altitude of 705 km, inclination of 98 • , and 16 d repeat cycle), with the ascending node crossing the Equator at approximately 13:45 LST daily (Schoeberl et al, 2008). As a result, OMI measurements take place at the same locations each year.…”

“…We use HNO 3 and temperature profiles from NASA's Microwave Limb Sounder (MLS), which is also onboard the Aura satellite (Manney et al, 2015;Schwartz and Read, 2015). This study uses the version 4.2 product with data screened according to Livesey et al (2017).…”

The Ozone Monitoring Instrument: overview of 14 years in space

“…Successful OMI validation field campaigns provide data to aid in relating surface observations to retrieved OMI column in- Schoeberl et al, 2008), DANDELIONS (Brinksma et al, 2008), and INTEX-B (Singh et al, 2009) have achieved this using vertically integrated aircraft and lidar data, and also by using measurements from a multi-axis differential optical absorption spectroscopy (MAX-DOAS) type instrumentation that produce OMI-comparable column amounts of trace gases and aerosols. Some examples of OMI retrieval improvements derived directly from using validation campaign data include Lee et al (2009) for SO 2 and Hains et al (2010) for NO 2 .…”

“…Total column O 3 from the sondes averaged 3 % greater than OMI columns , which considering the 5 % sonde uncertainty is not statistically significant. The sonde data were also compared with trajectory-mapped OMI minus MLS tropospheric O 3 residual (surface to 200 hPa; Schoeberl et al, 2008), yielding a statistically significant average discrepancy of 10 %.…”

High precision atmospheric CO<inf>2</inf> measurements from space: The design and implementation of OCO-2

“…Water vapor, temperature, and ozone are routinely measured with sondes, and such data has been incorporated into the satellite validation analysis [8]. Aircraft profiles of a wide range of tracer gases have also been used in the validation of satellite measurements.…”