ACE Validation

The accuracy and reliability of the results is established through comparison of ACE data with a series of other measurements made by other instruments. Both vertical profile and column measurements are used as part of the validation data set. These experimental results overlap as closely as possible in space and time with the ACE data.

A group of validation experiment teams from around the world has been assembled to collaborate on the ACE validation program. These teams use instruments on satellites, balloons, aircraft, and ships. Sites make routine or campaign ground-based measurements using Fourier transform (both infrared and UV/Visible) spectroscopy and differential optical absorption spectroscopy (DOAS), as well as lidar, Brewer spectrometer, and filter spectrometer techniques. These results provide several measurement sites for each of the ACE baseline data products: O3, CH4, H2O, NO, NO2, ClNO3, HNO3, N2O, N2O5, HCl, CCl3F, CCl2F2, HF, CO, aerosols, temperature and pressure. In addition, these experiments cover the majority of proposed species to be retrieved from the FTS and MAESTRO measurements.

The validation process has two phases: initial and ongoing. ACE data is initially compared to results from satellite-based instruments (and other measurement results as available). This initial validation phase is used to establish the reliability of ACE data products, and to understand the differences between ACE and other measurements. The ongoing validation phase ensures consistent data quality; throughout the life of the mission, comparisons to ground-, balloon-, and aircraft-based experiment data as well as satellite data are continual.

There is currently an ACE Validation Special Issue in Atmospheric Chemistry & Physics developed by our Validation Team. This publication is part of the initial validation phase and helps establish the reliability of ACE data products. This publication focuses on the Level 2 baseline species of Version 2.2 and Version 2.2-updates but also includes temperature, pressure and other interesting ACE data products. This publication marks the end of the "Initial" stage of validation and the beginning of the "Ongoing" stage.

Main Validation program webpage for ACE Science Team members and other authorized users.