Upper atmospheric processes as measured by collocated Lidar, infrasound, radiometer and airglow measurements
Abstract
To better initialize weather forecasting systems, a key challenge is to understand stratosphere-resolving climate models. The ARISE project (http://arise-project.eu/) aims to design a novel infrastructure integrating different atmospheric observation networks to accurately recover the vertical structure of the wind and temperature from the ground to the mesosphere. This network includes Lidar and mesospheric airglow observations, complemented by continuous infrasound measurements. Together with additional ground-based wind radar system, such complementary techniques help to better describe the interaction between atmospheric layers from the ground to the mesosphere and the influence of large scale waves on the atmospheric dynamics. Systematic comparisons between these observations and the ECMWF upper wind and temperature models (http://www.ecmwf.int/) have been performed at the OHP site (Haute-Provence Observatory, France). The main results are outlined below. - Systematic comparisons between Lidar soundings (NDACC, http://ndacc-lidar.org/) and ECMWF highlight differences increasing with altitude. Below 50 km altitude, differences are as large as 20°K. In average, the temperature appears to be overestimated by ~5 m/s in the stratosphere and underestimated by ~10 m/s in the mesopause. - Comparisons with collocated infrasound measurements provide additional useful integrated information about the structure of the stratospheric waveguide. Below 0.5 Hz, most infrasound signals originate from ocean swells in the North Atlantic region. As expected, since most long-range propagating signals travel in the stratospheric waveguide, improved detection capability occurs downwind. Deviations from this trend are either related to short time-scale variability of the atmosphere (e.g., large-scale planetary waves, stratospheric warming effects), or can be explained by changes in the nature of the source. We investigate possible correlation between unexpected propagation paths and unresolved atmospheric perturbations. - Additional ground-based sounding technique for measuring the vertical structure of the wind fields was deployed at OHP by University of Bern, Switzerland. As observed for the temperature, significant errors in the zonal wind model are noted between 40-60 km altitude. The mean flow of the zonal wind appears to be overestimated by ~40 m/s in the mesopause. - We also show that mesospheric airglow measurements (NDMC, http://wdc.dlr.de/ndmc/) can constrain the temperature where uncertainties in the model are the largest. Such collocated observations from different complementary sounding techniques offer a unique opportunity to provide detailed information on upper atmospheric processes from seasonal to daily scales, better understand atmospheric coupling processes and their influence on weather and climate.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2013
- Bibcode:
- 2013AGUFM.S23B2505L
- Keywords:
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- 3319 ATMOSPHERIC PROCESSES General circulation;
- 3334 ATMOSPHERIC PROCESSES Middle atmosphere dynamics;
- 3333 ATMOSPHERIC PROCESSES Model calibration