Ground-Based Observations with a Rayleigh-Mie-Raman Lidar from 15-120 km
| Autor: | Sox, Leda, Wickwar, Vincent B, Herron, Joshua P., Barton, David L., Emerick, Matthew T. |
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| Rok vydání: | 2013 |
| Předmět: | |
| Zdroj: | Leda Sox Graduate Student Posters |
| Popis: | Rayleigh lidar systems have historically made ground-based observations of the upper atmosphere (stratosphere and mesosphere) from 35-90 km. This technology has helped fill the data collection gap between the troposphere and space. Recently our Rayleigh lidar group at the Atmospheric Lidar Observatory on the campus of Utah State University (42° N, 112° W) upgraded the original lidar system in order to extend the measurement range for neutral densities and temperatures to higher altitudes and has increased the upper limit, so far, from 90 to 110 km. Next, we will extend the lower altitude limit downward to 15 km. This will enable us to connect densities, temperatures, and their fluctuations in the mesosphere and lower thermosphere to the drivers in the lower portions of the atmosphere. Extending measurements downward will lead to signals, not only from Rayleigh scatter off of small particles (N2 and O2), but also from Mie scatter off of much larger particles (aerosols). In order to separate the Rayleigh and Mie signals we will take advantage of the system’s greater sensitivity to measure Raman scatter from N2, between 15 and 35 km, thus making the system a Rayleigh-Mie-Raman (RMR) lidar. We can then apply the Klett Inversion algorithm to separate these signals in the data reduction. Such an extended altitude range will enable us to make observations of atmospheric processes and phenomena, such as disturbances, waves and sudden stratospheric warmings, which can ripple up from the ground throughout the atmosphere. This range will also enable an absolute calibration of densities with data from radiosondes and assimilative models like NCEP. The absolute calibration of atmospheric densities can provide a starting point for neutral models of the thermosphere, which are often used to predict satellite drag. In addition, the RMR lidar extended altitude range will provide significant overlap with satellite remote sensing measurements, which will help with calibration and validation efforts and in the extension of satellite measurements towards the ground. The RMR lidar will provide complementary measurements to those made by satellites by providing data that can measure the time evolution of atmospheric processes in one location, while satellite instrumentation gives global measurements of atmospheric processes. This talk will focus on a description of the system and the latest results as well as a discussion of the full upgrade design and how it impacts NASA efforts. |
| Databáze: | OpenAIRE |
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