Investigators huddle by a C-130 aircraft, owned by the National Science Foundation and operated by the National Center for Atmospheric Research, as it rests on the tarmac at the Churchill, Manitoba, Canada airport during the Tropospheric Ozone Production about the Spring Equinox (TOPSE) experiment (February 2000). The goal of TOPSE was to investigate the chemical and dynamic evolution of tropospheric chemical composition over mid- to high-latitude continental North America during the winter/spring transition, with particular emphasis on the springtime ozone maximum in the troposphere.
