The Canadian Arctic Validation of ACE for IPY campaign is making validation measurements for the ACE satellite mission in the Canadian Arctic between February to April during the two years of International Polar Year (2007 and 2008).  A suite of 12 instruments is used to determine total columns (and vertical profiles and partial columns, where possible) of the 14 ACE baseline target species, atmospheric extinction, temperature, and pressure.  Spectral, as well as trace gas, measurements from ground-based versions of ACE-FTS (PARIS-IR) and ACE-MAESTRO (MAESTRO-G) instruments will assist in assessing the quality of both the Level 1 and Level 2 ACE data under the chemically perturbed conditions found in the springtime Arctic.  Daily measurements are being made during the campaign.  These high temporal resolution results will give to give context to the sparse (in time and space) ACE occultation measurements.

The campaign is taking place at the Polar Environment Atmospheric Research Laboratory (PEARL) facility at Eureka, Nunavut.  Six weeks of observations are being made during Arctic spring in 2007 and 2008. This is a time when the perturbed stratospheric conditions can lead to chemical ozone loss.  A combination of on-site instrumentation (ozone lidar (DIAL) and high resolution Fourier transform infrared spectrometer (DA8 FTIR)) and instruments deployed for the campaign (UV/visible spectrometers and Fourier transform infrared spectrometer) are used to make the atmospheric measurements.  This year, two CANDAC instruments (UV/visible grating spectrometer and a Fourier transform infrared spectrometer (Bruker FTS).  The campaign is split into two phases:  the intensive and extensive phases.  The intensive phase takes place from February 21 – March 10.  During this time, measurements are made by all instruments and daily ozonesonde flights were launched.  The extensive phase continues from March 11 – April 1 with measurements by all instruments (mostly operating autonomously) and weekly ozonesonde flights.

Latitude of occultations within 500 km of Eureka, Nunavut