Na Wind/Temperature lidar offers a method to study the dynamics and thermal structure of the mesosphere and lower thermosphere (MALT) through Doppler methods. The University of Illinois system has been operated at both the USAF Starfire Optical Range in Albuquerque, NM (94, 98-00') and at the USAF AMOS Maui facilities with receiving mirrors that are 3.5 m in diameter. An autonomous receiving system is being developed which will provide unrestricted and continuous operational capabilities. The bi-static operational receivers will be coupled with multiple fibers so that Na (589 nm) returns from the MALT region and Rayleigh (355 nm) returns from the stratosphere and mesosphere can be received simultaneously. The system will be described with attention to increased efficiencies in the receiver.
The University of Illinois Fe (iron) Boltzmann temperature lidar was operated at the South Pole (90°S) from November 1999 to October 2001, and then at the Rothera Station (67.5°S, 68.0°W) from December 2002 to March 2005. This lidar transmits two UV wavelengths at 372 and 374 nm, and is able to measure the middle and upper atmosphere temperature, Fe density, polar mesospheric clouds (PMC), and polar stratospheric clouds (PSCs). In this paper, we analyze the PSC data collected in the winters and springs of 2003 and 2004 at Rothera, and compare them with the PSC data collected at the South Pole in the 2000 and 2001. PSCs were observed in the range of 15-28 km during the seasons from May/June to October at both locations. The PSC backscatter ratio, width, and altitude at Rothera are comparable to those at the South Pole. However, Rothera PSCs occur less frequently (~17.7%) and in shorter periods, compared to PSCs at the South Pole (~64.9%). At Rothera, PSC occurrence frequency in 2004 is only half of that in 2003, which is likely due to warmer stratospheric temperatures in 2004 associated with changes of the polar vortex. These are the first ground-based lidar observations of PSC at Rothera, and also the first in West Antarctica.
The University of Illinois Na wind/temperature lidar data collected at the Starfire Optical Range (SOR: 35N, 106.5W), NM, can be used to extract the dominant monochromatic inertial gravity waves and to characterize their features. By using simultaneously measured horizontal wind and temperature profiles the vertical wavelengths, intrinsic periods, and propagation directions can be determined using the hodograph method. A total of 700 waves were analyzed from about 300 h of observations. Waves with vertical wavelengths between 2 and 20 km and intrinsic periods between 1 and 20 h were fully characterized. 84.4% of the waves were propagating upwards. There was a prevailing direction towards the northeast in upward waves horizontal propagations over the year. This prevailing direction existed also in spring, summer and autumn. In winter, most waves propagated to the south and west. The filter theory of gravity waves propagating through the middle atmosphere can be used to give an explanation on the observations. Propagation directions of downward waves showed no prevailing directions over the year. A discussion was given on their different features for different seasons.
The University of Illinois Na wind/temperature lidar data collected at the Starfire Optical Range, New Mexico, can be used to present annual variations of the mesospheric mid-night horizontal winds. For each night, the winds profiles from the 11:00pm to 1:00am were smoothed in 1km altitude and then averaged in time to give mid-night winds profiles. All mid-night winds profiles within one month were averaged again to give mid night winds profiles of that month. The annual variations of the mid-night winds in the altitude ranges from 84km to 100km were obtained using a total of 46 nights lidar data distributed over the months except July. Zonal mid-night winds showed strong annual oscillations. Prevailing westerly winds blew over low altitudes in the winter months and over high altitudes in summer months. Meridional mid-night winds also showed annual or semi-annual oscillations. Southward winds dominated below 90km from April to October, and at about 96km during winter months and summer months except January. Correlations were found between the meridional mid-night winds and the mid-night temperatures. When the meridional winds blow from south, temperatures become warm. Results were compared with calculations of the HWM93 and the mid night winds observed with a MF radar at Urbana. Similar wind structures can be found in their results. The major differences are that strong westerly winds above 94km in March and April and strong northward winds at 96km in January were observed with the lidar. The winds values of the lidar and the MF radar data are larger than those of HWM93. Activities of inertial gravity waves and tidals might contaminated estimations of annual winds with the lidar data and contribute partially to their differences.
The Waves middle class Explorer mission (WE) is proposed to observe and quantify the effects of small-scale internal Gravity Waves (GW) in the Earth's atmosphere from source regions in the troposphere and lower stratosphere to the mesosphere, lower thermosphere, and ionosphere (MLTI) where the GW have their most dramatic effects. These are now understood to be a key element in defining large-scale circulation, thermal and constituent structures, and variability of the stratosphere and MLTI. The WE instrumentation consists of 5 nadir and limb viewing sensors of the wave perturbed emission structure due to GW throughout the source and affected regions. The WE PI is Prof. G.R. Swenson. This paper addresses the measurement strategy and implementation for two of these instruments, the Source Wave And Propagation Imager (SWAPI), and the Hydroxyl Airglow Wave Imager (HAWI). The SWAPI uses multi-spectral sublimb imaging measurements in the CO2 (nu) 3 band near 4210 nm to identify GW sources, and their propagation through the stratosphere. Its measurement strategy is driven by data, particularly sublimb images in the CO2 (nu) 3 band that were obtained by instrumentation deployed on the Midcourse Space Experiment (MSX) satellite, and by the WE team member's data analysis and models. Similarly team member's ground based observational experience and data analysis drives the HAWI measurement strategy.
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