Yves J. Rochon

The Wind Imaging Interferometer (WINDII) on the Upper Atmosphere Research Satellite: A 20 year perspective

The Wind Imaging Interferometer (WINDII) was launched on the NASAs Upper Atmosphere Research Satellite on 12 September 1991 and operated until 2003. Its role in the mission was to measure vector winds in the Earths atmosphere from 80 to 110 km, but its measurements extended to nearly 300 km. The approach employed was to measure Doppler shifts from a suite of visible region airglow lines emitted over this altitude range. These included atomic oxygen O(1S) and O(1D) lines, as well as lines in the OH Meinel (8,3) and O2 Atmospheric (0,0) bands. The instrument employed was a Doppler Michelson Interferometer (DMI) that measured the Doppler shift as a phase shift of the cosinusoidal interferogram generated by single airglow lines. An extensive validation program was conducted after launch to confirm the accuracy of the measurements. The dominant wind field, the first one observed by WINDII, was that of the migrating diurnal tide at the equator. The overall most notable WINDII contribution followed from this; determining the influence of dynamics on the transport of atmospheric species. Currently, non-migrating tides are being studied in the thermosphere at both equatorial and high latitudes. Other aspects investigated included solar and geomagnetic influences, temperatures from atmospheric scale heights, nitric oxide concentrations and the occurrence of polar mesospheric clouds. The results of these observations are reviewed from a perspective of twenty years. A future perspective is then projected, involving more recently developed concepts. It is intended that this description will be helpful for those planning future missions.

Radiative Impact of Ozone on Temperature Predictability in a Coupled Chemistry–Dynamics Data Assimilation System

Abstract The objective of this study is to investigate the impact on temperature forecast of using ozone analyses for the computation of heating rates in a three-dimensional variational data assimilation (3D-Var) system with a coupled model. The system is based on a tropospheric–stratospheric forecast model that includes a comprehensive stratospheric chemistry module for online resolution of the dynamical, radiative, and photochemical interactions. The system assimilates conventional observations as well as temperature and ozone measurements from the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) instrument. Several data assimilation cycles have been performed over the period August–October 2003 to produce a set of analyses that have been used for launching an ensemble of 10-day forecasts. Temperature and ozone forecasts have been compared with MIPAS and radiosonde observations in different regions. Results show that, in the absence of ozone assimilation, the impact of using a prognosti...

The Environment Canada Pan and ParaPan American Science Showcase Project

AbstractThe Pan and Parapan American Games (PA15) are the third largest sporting event in the world and were held in Toronto in the summer of 2015 (10–26 July and 7–15 August). This was used as an ...