Timothy J. Kane - US grants

This is a study to investigate the relationship between fine-scale neutral atmosphere structure, acoustic gravity waves, tides and the presence of sporadic sodium, iron and ion layers in the middle atmosphere. The study will make use of data obtained with radars and lidars during several observational campaigns over the last fifteen years. The observations will be compared to determine differences in the low and mid-latitude tidal and gravity wave processes and how they relate to layer formation. A parallel theoretical/numerical modeling effort will concentrate on formation of sporadic neutral and ion layers and on the breaking of acoustic gravity waves above the mesopause. The lidar data will be added to a centralized data base that will be accessible via the Mosaic networking system.

The PIs will continue comprehensive studies of mesosphere and lower thermosphere aeronomy. This program will utilize Incoherent Scatter Radar (ISR) data and optical facilities of Arecibo Observatory, a sodium/iron resonance lidar at Arecibo on a campaign basis, and data analysis coupled with modeling/theoretical studies conducted at Penn State. The renewal grant will cover: (1) continued ISR/lidar observational and modeling investigations of the relationship (or "coupling") between small-scale neutral atmosphere structure, acoustic-gravity waves, tides and the presence of sporadic metal and ion layers; (2) temperature dependent chemistry; (3) the origin of the 6-hour tide; (4) the complex of newly observed short-period waves and ion layers in the 100-250km region; (5) the origin of the (sometimes complex) ion layer structures in the 90-100km region and their relationship to sporadic metal layers; and (6) apparent "convective" processes as observed in the sodium and ion layers as well as in the "background" ionosphere.***

ATM9813828

The investigators will study arctic summer phenomena, specifically noctilucent clouds (NLC) and gravity wave and tidal propagation through the middle atmosphere. The work involves an extension of the lidar capability at Sondrestrom, Greenland, into daytime operations by implementing a liquid crystal double etalon system.. The researchers will investigate the following questions: (1) What are the local time and seasonal dependencies of the behavior and characteristics of NLCs, (2) What is the impact of gravity waves and tides on the formation and lifetime of NLCs, and (3) Are there longitudinal differences in NLC observations? The daytime lidar capability will enable the gravity wave influences on NLCs to be more thoroughly analyzed, as well as the tidal influences on the basic characteristics of the clouds. Recent studies suggest that continued increases in tropospheric methane should result in an increase in mesospheric water vapor concentrations leading to more frequent NCL occurrence, particularly at lower latitudes. The gravity wave influences on this occurrence must be fully understood to assess the role of anthropogenic changes.

A two-year, systematic observational study of the seasonal variations in mid-latitude metal layer dynamics is proposed at the Arecibo Observatory. The occurrence and behavior of various metal layers (Na, Fe, K, Ca) will be investigated using the Arecibo lidars and the incoherent scatter radar during summer, winter and equinox periods. Such a study will provide a comprehensive view of metal layer dynamics as a function of season allowing us to explore the coupling between neutral dynamics, chemistry and the plasma. Past studies at Arecibo have concentrated on case studies of metal species at particular times of year, but the PI proposes a systematic year-round study utilizing the complete capabilities of the Arecibo lidars. In addition, observations during summer Es maximum coupled with observations at other times of year will provide insight into the relationship between metal layer dynamics and the formation of Es and associated plasma irregularities. Past observations at Arecibo have shown that sporadic ionization layers are often associated with sporadic metal layers, such as sodium, but the relationship between such layers when instabilities are present has not been explored in detail. The proposed study represents an exciting opportunity to establish a baseline for the understanding of metal layer morphology and dynamics at mid-latitudes. It will also produce important insights into Es formation and associated irregularities.

A Rayleigh lidar system will be deployed to Maui, Hawaii, to measure absolute temperatures and relative atmospheric density throughout the stratosphere and mesosphere regions in combination with simultaneous observations of upper mesosphere and lower thermosphere winds and temperatures carried out by the U. of Illinois sodium lidar system. The 10 watts laser transmitter on loan from the Univ. of Illinois would be combined with the 3.7 m USAF-AEOS telescope located on Mt. Haleakala to achieve a power aperture product unmatched by any other Rayleigh lidar system regularly operating today. These lidar measurements would be supplemented by all sky imaging observations provided by the Univ. of Illinois OH intensity imaging system and the Utah State Univ. all sky imaging system of temperature and intensity for OH and O2 emissions. This suite of measurements would provide for focused investigations of small-scale wave propagation properties within the stratosphere and mesosphere regions. Larger scale dynamical measurements would be possible by combining these results with those from the Illinois meteor radar system.

A global gravity wave model using ray-tracing techniques is produced and verified with ground-based and satellite data.. The methodology begins by ingesting daily analysis and five-day forecasts from the National Weather Service to identify tropospheric structures (synoptic and mesoscale systems, thunderstorms, hurricanes, etc.) that are known to be gravity wave sources. Gravity wave spectra assigned at the identified tropospheric sources are then propagated from the troposphere through the middle atmosphere and to 400 km altitude using extant linear ray-tracing numerical codes. The background atmosphere above the tropopause is characterized by models and by available data. The over-arching purpose is to evaluate the hypothesis that gravity-wave sources as triggers of Equatorial Spread-F (ESF), a phenomenon in the equatorial ionosphere characterized by large ion density depletions, or bubbles, reaching altitudes of 500 km and higher. These ionospheric irregularities are known to produce Global Positioning System radio frequency scintillations, and stand as an outstanding forecasting challenge for the Space Weather community.

0968650 Pennsylvania State University; Mohsen Kavehrad
0968651 Tufts University; Valencia Joyner
0968662 University of California-Riverside; Zhengyuan Xu

The Center for Optical Wireless Applications (COWA) will focus on developing new devices using White Light Emitting Devices (WLEDs). Pennsylvania State University (PSU), Tufts University (TU) and the University of California-Riverside (UCR) are collaborating to establish the proposed center, with PSU as the lead institution.

The primary goals of this planning project are to initiate formal partnership with various industry partners and national laboratories that have an interest in optical wireless applications designs, and to discuss fundamental issues and topics for research. The main objective of the envisioned research projects at the proposed Center is to develop a new generation of environment-friendly extremely wideband optical wireless technology applications. The PIs' effort will involve work in relevant device designs, in optical wireless communication systems (physical layer), in networking, sensing, and in imaging.

The proposed Center has the potential to improve the profitability of US manufacturing by developing new optical wireless devices that will improve communication systems, reduce energy consumption and pollution. The proposed Center will offer a series of short courses to update the knowledge of the current workforce and will help universities to tailor new course offerings and to modify existing course offerings to better provide instruction for related areas and industry needs. The Center plans to promote diversity, building on all three universities' high ranking in education of minorities. In addition, the Center will work with existing university resources to recruit and build strong relationships with minority and women-owned companies and provide a collaborative community, within which these companies can contribute expertise, expand their networks and become more globally competitive.

I/UCRC for Optical Wireless Applications

1160924 Pennsylvania State University; Mohsen Kavehrad
1161010 Georgia Tech; Gee-Kung Chang

The Center for Optical Wireless Applications (COWA) will focus on generating technology that enables manufacturing of specific devices with larger communications capacity, employing integrated opto-electronics device design with interfaces necessary to facilitate collaborative device, system and network design. Pennsylvania State University (PSU) and Georgia Tech (GT) are collaborating to establish the proposed center, with PSU as the lead institution.

The objective of this proposal is to establish an NSF-sponsored Industry & University Cooperative Research Center on Optical Wireless Applications (COWA), in order to explore Optical Wireless Technology and economic potentials of energy efficient light sources through innovative designs and applications of solid-state optical sources and detectors for a wide range of practices that include optical imaging, remote sensing, communications and networking. The envisioned Center is based on the integration of interdisciplinary expertise at PSU, and GT with devices and systems-based engineering design and networking concepts.

The envisioned Center will include efforts to instill the cultural paradigm shift associated with promoting research programs of interest to both industry and universities; exploring and extending the interface between engineering systems design, networking and integrated electro-optic device designs; improving the intellectual capacity of the workforce through industrial participation and conduct of high-quality research projects; and developing curriculum in components, systems and networks design aspects of optical wireless applications. The results of this research are expected to contribute to the business competitiveness, energy security, environmental protection, and climate forecast. The proposed Center will make every effort to promote diversity. In addition, it will work with existing university resources to recruit and build strong relationships with minority and women-owned companies.