| 英文摘要: | This award would would upgrade the upper atmosphere lidar facility located at the Poker Flat Research Range (PFRR), Alaska (65N, 147W) to achieve a wind and temperature (W&T) measurement capability for the mesosphere and lower thermosphere (MLT) region using the resonance backscatter returns from the sodium layer to obtain these results. This instrument would be applied to undertake correlative studies addressing new challenges in mesosphere and lower thermosphere (MLT) polar dynamics as well as extending ongoing work on the study of ion-neutral coupling processes. A key element of the award would be the transfer of the Na resonance wind-temperature lidar, currently at the Arctic Lidar Observatory for Middle Atmosphere Research, Norway (69N, 16E), to the Lidar Research Laboratory (LRL) at PFRR. This lidar system when established at Poker Flat would be capable of measuring three-dimensional wind, neutral temperature and sodium density profiles at high vertical resolution and temporal cadence. The lidar range coverage would normally be 80-105 km, and when neutral Na is present at higher altitudes (sporadic layer formations) can then be extended up to ¡140 km into the lower thermosphere. This facility will represent an excellent means of training young optical engineering physicists that would then be well suited for many possible career paths in academia and industrial research.
The major scientific goals of the research include the following objectives:
1. characterization of gravity wave (GW) propagation, refraction, ducting, and energy and momentum transports in variable environments, e.g., MLT responses to stratospheric warmings,
2. quantification of GW instability dynamics driving energy and momentum deposition, turbulence, heat, momentum, and constituent transports, and mixing,
3. understanding the interactions of GWs with tides and planetary waves, their influences on these fields, and the evolution of the wave spectrum with altitude, and
4. contributing to an improved understanding of ion-neutral coupling in the E region.
Studies employing the PFRR lidar system will benefit from current and pending measurement capabilities at PFRR, including ground-based imaging of neutral and plasma dynamics, the construction of a new meteor radar, and in situ measurements made possibly by pending and future rocket measurements. The PFRR lidar team also has extensive modeling capabilities that will continue to benefit the interpretation and understanding of lidar and correlative instrument measurements. |