DOI: 10.5443/11400
title: The Polar Environment Atmospheric Research Laboratory (PEARL) and the International Arctic Systems for Observing the Atmosphere (IASOA)

description: Year-round (365/24) operation of the PEARL complex has been achieved with more than 25 operating instruments and associated data downloads and archiving. A particular strength of PEARL is the ability to collect data during the winter when there are few other measurements but the atmosphere undergoes important changes. This project encompassed eight sub-projects: Project 1: Validation of space-based cloud properties and precipitation characteristics. The measurements and studies at PEARL have enabled better understanding of current satellite measurements and provided input for designs of future instrumentation. Project 2: Radiation and energy budget closure at the surface. Analysis has yielded significant results on the high (temporal) frequency behaviour of aerosols in the Arctic atmosphere. Project 3: The Coordinated LIDAR measurements project. The first characterization of stratospheric aerosol layers in the high Arctic has been achieved. Project 4: Coordinated upper atmosphere measurements. Atmospheric tides, or oscillations of period mainly 12 and 24 hrs, are the 'canary' of the atmosphere, as their variable presence in the upper atmosphere depends upon their source (e.g. solar heating of ozone, condensation of water vapour, etc.) in the lower atmosphere, and also the chemical, thermal and dynamical state of the underlying atmosphere. Project 5: Coordinated and intensive stratospheric measurements. Intensive measurements of atmospheric composition in the high Arctic have been combined with data from other Arctic observatories, model simulations, satellite data, and dynamical analyses to characterize year-to-year changes in stratospheric ozone and other trace gases that control the ozone budget. Project 6: Outreach program to bring CANDAC scientists to northern Nunavut schools, to explain what we are doing in the Arctic and why it is important. These scientists also provide examples to the students of possible career options in the sciences. Project 7: Cooperative education program for northern college students. Training scientists for work in the Arctic is important, as is supplying Northern students with opportunities to gain experience in real-world situations. Project 8: The Northern Experience Program. Showing students what life is like in the High Arctic proved to be a powerful learning tool. Students' lives and perspectives were significantly changed by the experience.
description: Purpose: The climate of the Arctic is changing more rapidly than other parts of the globe and these changes are impacting temperate climates. Therefore, our understanding of the complex relationships between surface and atmospheric interactions and radiation, clouds and precipitation are important contributions not only to understanding Arctic changes, but changes in the weather and climate of all Canadians. Within the context of the International Polar Year (IPY), The Polar Environment Atmospheric Research Laboratory (PEARL) plans to achieve three objectives: 1) to make an extensive and intensive set of measurements of the Arctic atmosphere to produce a unique data record of the atmosphere for the future and interpret those records in terms of current science needs, 2) to co-ordinate with other observatories under the umbrella of the International Arctic Systems for Observing the Atmosphere (IASOA) initiative to further IPY objectives, and 3) to connect to Northern and Southern communities for training, education and outreach. PEARL is a unique national and international resource. It is located on Ellesmere Island at Eureka, Nunavut (80N, 86W). Built in 1993 by Environment Canada and operated as the Arctic Stratospheric Ozone observatory until 2002, it was mothballed due to lack of funding. It was revitalized in its present form when a collaboration between university researchers and government departments, the Canadian Network for the Detection of Atmospheric Change (CANDAC), undertook its operation in 2005. PEARL is situated about 15km from the Eureka weather station and derives much of its support from that location. Access is by charter plane and by an annual sea-lift. PEARL is a 'whole atmosphere' laboratory containing instrumentation to study the atmosphere from the ground to about 100 km. Since the laboratory is at 600 m above sea level, an additional site 'the zero altitude PEARL auxiliary laboratory (ØPAL)' was established beside the Environment Canada weather station at approximately sea level. In addition, the Surface Atmospheric Flux and Irradiance Remote Extension (SAFIRE) site, located near the Eureka runway, is used for those experiments that need to be away from any outside interference. The PEARL/ØPAL/SAFIRE equipment roster includes LIDARs, radars, spectrometers, and optical instruments suitable for active and passive probing of the atmosphere, its physical and radiative states, and its composition.
description: Summary: The Arctic atmosphere is expected to undergo more dramatic changes in the coming years than will occur at lower latitudes. At the Polar Environment Atmospheric Research Laboratory (PEARL) on Ellesmere Island, more than a dozen instruments operate year-round to study the atmosphere from ground-level to 100km above ground. Clouds, rain, snow, sun and wind are among the climate-related factors and processes that are being studied. PEARL is providing an abundance of information on changes in atmospheric composition and weather in the Canadian High Arctic. Together with long-term monitoring at similar Arctic and other research sites worldwide, this project is contributing to a better understanding of global atmospheric change.