As the sun comes up each year over the Arctic, the combination of atmospheric dynamics and chemistry causes perturbations in the Arctic atmosphere. Ozone depletion is common, and enhancements and depletions beyond the background levels of many trace gases are observed. Since 2004, a suite of instruments has been deployed to Eureka, Nunavut between February and April to make measurements of these trace gases during spring time. These instruments serve a dual purpose - they directly measure the conditions of the atmosphere over Eureka, and they also serve to validate the measurements made by the instruments on board the Atmospheric Chemistry Experiment (ACE) satellite as it measures these gases all over the Earth.

The Canadian Arctic Validation of ACE for IPY campaign will be making intensive validation measurements for the satellite mission from Eureka, Nunavut, between February and April 2007 - 2009 as part of the International Polar Year.  A suite of 12 instruments will be used to determine total columns (as well as partial columns and vertical profiles 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 context to the sparse (in time and space) ACE occultation measurements.

The campaigns are taking place at the Polar Environment Atmospheric Research Laboratory (PEARL) facility at Eureka, Nunavut.  More than six weeks of observations will be made during the Arctic spring, when the perturbed stratospheric conditions can lead to chemical ozone loss.  Instruments especially deployed for the campaign include UV/Vis spectrometers, and the ground-based versions of both ACE instruments, PARIS-IR and MAESTRO-G. In addition, the campaign will make use of extensive on-site instrumentation, including Environment Canada's DIAL ozone lidar and Bomem DA8 Fourier transform spectrometer (FTS), and CANDAC's Bruker FTS and UV/Vis spectrometer.  The campaign is split into two phases:  the intensive and extended phases.  The intensive phase takes place from February 21 – March 11.  During this time, measurements are made by all instruments and daily ozonesonde flights are launched. A team of scientists will be at the station, ensuring maximum data collection. From March 12- April 8, the campaign continues (with fewer scientists) as the extended phase. During this time, measurements will be by nearly all instruments (mostly operating autonomously), and ozonesonde flights will be made weekly.

This website serves as the portal to the 2009 campaign. Follow our adventures with our daily journal and photos from the campaign.

Interested in ACE? This plot shows the latitude of ACE occultations during the campaign: Latitude of occultations within 500 km of Eureka, Nunavut. Special ozonesonde launches will be made at the times of its nearest overpasses - namely on February 26 and March 9.