Denise Thorsen - US grants

This grant develops the Platteville Atmospheric Observatory, located in Platteville, Colorado. The observatory currently has VHF, UHF, and boundary layer wind profilers for lower atmospheric measurements of winds, waves and stability. The PI plans to establish a medium frequency radar and all-sky meteor radar, providing measurements of upper atmosphere winds. She will also upgrade the VHF wind profiler and UHF boundary layer profiler to provide greater sensitivity for atmospheric coupling and precipitation studies. In sum, these acquisitions, developments and upgrades will implement research of large scale wave motions and their influence on circulation, wave-wave interactions, coupling of energy and momentum between regions of the atmosphere via gravity waves, boundary layer evolution, and land-atmosphere hydrological processes.

Through climatological studies of the mesospheric wind latitudinal variation, the investigator clarifies wave activity coupling from the tropopause to the mesosphere, and differential forcing of the mesosphere by gravity waves. She uses one year worth of data, collected from a chain of medium frequency radars spanning sub-tropical and mid-latitude regions. Her comprehensive study compares the climatological variability of mesospheric wave activity at each station in the latitude chain. These compares provide quantitative measures of the latitudinal variation of wave activity. Simple models, assessed for their accurate reproduction of the mesospheric wave activity's characteristics, incorporate wave propagation, saturation and critical layer filtering. Thorsen is aiding future modeling efforts, by clarifying the dominant mechanisms controlling wind variance (when observed by radar).

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The investigators will conduct two extended measurement campaigns involving meteor and medium frequency radars, a CCD spectrograph, and a lidar. The objective is to study systematic biases in horizontal wind measurements between the 30 and 40 MHz all-sky meteor radars, and the medium frequency radar at Platteville Atmospheric Observatory, and a sodium lidar located at Colorado State University. Also, by making coincident measurements, the investigators will validate a new technique for determining mesopause temperatures using meteor radar data. The instruments will be operated for as many nights as possible during two months, one in summer and one in winter. The comparison will be conducted using statistical techniques to provide an objective, quantitative determination of any systematic biases that exist in neutral wind and temperature measurements from the various techniques. The results will contribute to the CEDAR/TIMED program. CEDAR, which stands for Coupling, Energetics, and Dynamics of Atmospheric Regions, is a global change program that combines theoretical modeling with ground-based measurements to study the upper atmosphere and ionosphere. TIMED, for Thermosphere, Ionosphere, Mesosphere Energetics and Dynamics, is a NASA satellite program to study similar regions of the atmosphere. The joint CEDAR/TIMED program aims to coordinate ground-based and space-based observations to achieve better understanding of physical processes in the lower thermosphere and ionosphere.

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The investigators will study the dynamics of the mesosphere and lower thermosphere over Antarctica using measurements from the TIMED instruments and a meteor radar to be installed at South Pole station. Specific science objectives include: the space-time decomposition of wave motions; delineation of the spatial climatology over Antarctica with emphasis on the structure of the polar vortex; dynamical response to energetic events; and interannual variability. The proposed meteor radar is a VHF system that will be able to measure the spatial structure and temporal evolution of the horizontal wind field over the South Pole. The investigators will also make use of existing ground-based radars at Davis, Syowa, Rothera, and Scott Base in the determination of the spatial climatology. Wind and temperature measurements to be made by NASA's TIMED satellite during orbits over the South Pole will provide opportunities for combined ground-based and space-based experiments and validation activities.

This proposal is for the study of electric field effects on meteor trails in the equatorial region. Additionally, the PIs seek to understand any deviation of the radar scattering properties of a meteor trail from traditional specular reflection processes.

These scientific goals require the upgrade and continued operation of an existing meteor radar at Piura, Peru (5S, 81W). The upgrade at this site consists of installing a complete all-sky meteor radar system, so that the angle-of-arrival of meteoric backscatter can be unambiguously determined. In addition, archive data from Christmas Island will be analyzed for meteor winds as well. As a byproduct of this work routine mean wind, tidal amplitudes and phases, and meteor decay statistics will be available to the scientific community via a web server.

The next generation of wireless is in distributed sensor networks. Applications in this area are a rapidly growing research area. The project will investigate possibilities for coordinated action to improve the energy efficiency in distributed sensor network on all levels, from software to component design to system integration. The overall goal and impact of this will be the decrease in the cost of sensor network, allowing wider, more capable deployments for generalized information gathering and surveillance. A test-bed environment for energy-efficiency and performance evaluation of reconfigurable hierarchical networks of sensors will be established at the Center for Nanosensor Technology at the University of Alaska Fairbanks. Another anticipated benefit of such intelligent surveillance sensor networks is the extension of the same principles to everyday applications of distributed sensor networks.

PARTICIPATING INSTITUTIONS:
University of Alaska Fairbanks (UAF - main campus)
University of Alaska Southeast (UAS - campus in Juneau)


PROJECT DESCRIPTION
This project is expanding access to Electrical and Computer Engineering by transforming an introductory electrical engineering course into an interactive hybrid-teaching model, using a combination of face-to-face and online peer/teacher instruction. This course includes both inter-campus collaborative hands-on laboratory and team project experiences.

The project is addressing the needs of three very different populations of students: (i) the traditional engineering students attending the University of Alaska Fairbanks (UAF) main campus; (ii) students enrolled in the pre-engineering program at the University of Alaska Southeast (UAS) campus in Juneau; and (iii) students attending an Alaska Native serving community campus in rural Alaska. The delivery of an exemplary, financially responsible, engineering education in each of these communities has unique challenges, including cost and availability of an instructor, cost and availability of laboratory facilities, diversity of students' prior knowledge and cultural experiences, and variety of students' learning styles.

The project has three goals:
Goal 1: Deliver a hands-on electrical engineering lab course to place-bound pre-engineering and Alaska Native serving community campuses in Alaska synchronously with the identical course delivered face-to-face on the main engineering campus at UAF.
Goal 2: Restructure the lab component of the class to require inter-campus collaboration between the students through data sharing and discussions in the hands-on laboratories and team projects.
Goal 3: Develop expertise in Engineering Education through detailed assessment and evaluation of the engagement and learning of students, both those participating face-to-face and via distance.

The team is studying the effectiveness of inter-campus collaboration to improve both retention and academic achievement across three Alaska communities. This is the first hands-on engineering lab course delivered by distance in Alaska; therefore, it is transforming the way engineering education is delivered in the state.


BROADER SIGNIFICANCE
The project is directly impacting the availability of engineering curriculum for the geographically dispersed student population in Alaska, especially the Alaska Native communities in rural Alaska. The project is creating a successful "blueprint" for development and assessment of distance-delivered laboratory-based courses, particularly for inter-campus collaborations. The effort is transforming the educational experience of the often-isolated, place-bound students in rural communities - through building their social capital and connecting them to a larger learning community. This inter-campus collaboration is generating a deeper discussion of variations and outliers in measurements and providing experiences that are more reflective of the global work environment.

The upper atmosphere within the mesosphere and lower thermosphere (MLT) regions (80 to 105 km) is continually populated with waves generated in the lower atmosphere by a variety of weather-related sources or with waves generated by auroral activity. This award would deploy to the Poker Flat rocket range located near Fairbanks, Alaska, a state-of-the-art meteor radar system that would make middle atmosphere wind measurements with good height resolution (1-2 km) and good temporal resolution (30 to 60 min). The application of this instrument is to study the dynamics of the Arctic MLT region continually day and night. These new wind observations would be integrated into a study that combines radar and lidar measurements, satellite measurements, and meteorological re-analyses, to understand the wave-driven circulation of the Arctic polar atmosphere. The satellite observations and meteorological re-analyses yield synoptic-scale measurements of the mesosphere, stratosphere and troposphere. The lidar observations yield high-resolution height profile temperature and density measurements that allow characterization of the existing planetary waves, tides, and gravity waves. The new radar would yield accurate MLT wind measurements that complete the characterization of these waves and would support modeling efforts aimed at improving the understanding of the wave-driven global circulation. The investigators would use or re-analyze the MERRA (lower atmosphere below 80 km) and SABER profile data (to cover higher altitudes for the range of 90 to 110 km) to characterize the synoptic stratospheric and lower mesospheric activities. The radar observations would help to understand the extent to which nitrogen compounds produced by energetic particle precipitation in the thermosphere contribute to the composition of the lower atmosphere by transport across the MLT region into the stratosphere and the ozone layer. The activity in this new award will support the education and training of students in science and engineering. The award would extend research infrastructure in the Arctic, especially at the Poker Flat Rocket Range, enhance international and national collaborations, and promote collaboration among observers and modelers. The research results will be integrated into the University of Alaska programs and disseminated through a variety of professional, educational, and outreach programs.

Analyses based on temperature and pressure measurements and gradient winds are used to describe planetary wave activity in the stratosphere and lower mesosphere, and the circulation follows well-defined synoptic patterns of cyclones and anti-cyclones. However, direct wind measurements are increasingly important at higher altitudes where the amplitudes of shorter-period waves and tides are the largest component of the winds. The activity would provide new observations as well as a coherent framework for understanding these interactions.

Accurate knowledge of sea ice thickness over large scales is crucial for understanding the current and future states of the Arctic ice cover, and for near- and long-term predictions of Arctic marine environments. With the Arctic ice pack undergoing a major transition from perennial to seasonal ice, ice thickness - more so than ice extent - is a key variable describing the state and evolution of the ice-ocean system. However, methods of observing sea ice thickness at regional or basin scales with sufficient accuracy and resolution to capture growth and melt processes, detect hazards, or assess habitat quality are lacking. This project will develop an Airborne electromagnetic (AEM) snow radar system capable of being integrated into long-range Unmanned Aerial Systems (UAS). This will allow acquisition of basin-scale ice thickness and snow depth data as part of a network for Arctic observations that addresses information needs of researchers, local communities and industry. This MRI development project will contribute to NSF's Navigating the New Arctic Big Idea.

AEM methods offer a novel means of measuring sea ice thickness over the full range of thicknesses found in the Polar Regions. By remotely sensing the positions of the upper and lower surfaces of the ice cover, AEM measurements typically achieve an accuracy of better than 10% of the total thickness, with less sensitivity to uncertainties in snow cover or sea surface topography. Development and commissioning of the Long-range Airborne Snow and Sea Ice Thickness Observing System (LASSITOS) will also provide opportunities for education and training, including capstone projects for the University of Alaska Fairbanks' new minor in aeronautical engineering and student involvement in comprehensive calibration/validation field activities. LASSITOS is expected to generate interest among native students from coastal villages in northern Alaska, who represent another key stakeholder group for sea ice information. The leader of this project is an early-career researcher.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.