Executive Summary

As this 2003 Annual Scientific Report will show, there were many landmark events for the Atmospheric Technology Division. While the thrust of our mission remains unparalleled support of field projects with state-of-the-art observing systems, technical, and data support, this year has seen an emphasis on a new generation of observing facilities. For example, ATD's scientists are leading the way into the future of scientific research capabilties with the development of eye-safe lidars that will allow scientists to study anthropogenic aerosols (including pollutants) in populated areas. Such capabilities will expand the repetiore of atmospheric measurements available to scientists. ATD is excited to be such an integral part of this ever-deepening understanding of our earth systems.

The establishment of our new Analytical Photonics & Optoelectronics Laboratory (APOL) saw immediate response from NASA scientists in the form of a request to study alarming formaldehyde levels on board the space station. The findings of the APOL scientists were revealing and will be pivotal in NASA's future modifications to the space station, insuring the safety of scientists exploring the outer reaches of our atmosphere.

The level of data support ATD provides to the scientific community was bumped up a notch with the advent of ATD's Real-Time Data Control and Coordination (RDCC), first lauched during last summer's BAMEX (Bow Echo and MCV Experiment) in the central US. With the RDCC, scientists aboard all three aircraft were able to maintain real-time communications with, and control over, ground operations at a level that far exceeded what ATD has provided in the past.

The Intelligent Sensor Array (ISA) stands to revolutionize the way scientists gather data about land atmosphere problems, such as the Greenhouse Effect. The ISA allows for faster, less expensive deployment of sensory equipment over a much wider range, so that entire biosystems can be studied. It can be networked with other systems for simultaneous data collection or analysis on a short- or long-term basis.

ATD made great strides to complete the engineering/development phase of the Driftsonde, a balloon which can deliver observing systems to the remotest regions of the ocean. Data from these areas are imperative to furthering scientific understanding of the interaction between oceanic atmospheric conditions and weather patterns in adjacent landmasses. The Driftsonde promises to be efficient, cost-effective way for scientists to accomplish this.

Ground was broken last summer for the new Hangar at Jeffco Airport, where ATD's Research Aviation Facility operates. This hangar is making way for the latest airborne observing system in our fleet, the High-performance Instrumented Airborne Platform for Environmental Research (HIAPER).

LIght Detection and Ranging (LIDAR)

ATD completed development of an eye-safe aerosol backscatter lidar (laser radar) prototype during the summer of 2003. Over 150 hours of data were collected from the FL-1 lidar lab during tests. The system performs extremely well and is capable of "seeing" aerosol features to more than 10 km range. Efforts are underway to install the system in a seatainer with a beam-steering unit for field deployment in FY04. A manuscript describing the system has been prepared and will be submitted to a scientific journal soon. Results of the summer tests can be viewed on the ATD website.

The eye-safe aerosol backscatter lidar is novel in that it works at a wavelength (1.5 microns) which poses no hazard to the eyes and has sufficient sensitivity to detect both naturally occuring and anthropogenic aerosols (wind blown dust, smoke, pollution, etc). Because the laser beam poses no ocular hazard to the public, it can be used by atmospheric scientists in locations where non-eye-safe lidars could not be used (such as cities). ATD scientists envision this technology maturing for continuous monitoring and automated display of aerosol pattern maps over urban areas.

See more detail on ATD's LIDAR developments here.

Analytical Photonics & Optoelectronics Laboratory (APOL)

Establishment of APOL Facility

The Atmospheric Technology Division provided major funding for the establishment of the new APOL facility, with support from the NCAR Director’s Opportunity fund and ACD this past year. One of the major intents of this laboratory is to develop advanced sources and absorption cells for a new real-time isotope-resolving CO2 sensor and to serve as a reference lab for studies of air quality on the International Space Station.

APOL Support for the International Space Station

In the past year the APOL group, in collaboration with the University of Hartford, provided support to NASA to address concerns about the increase of contaminants in the space station. Scientists at the NASA Johnson Space Flight Center Toxicology Group have established spacecraft maximum allowable concentrations (SMACs) for a variety of selected airborne contaminants onboard the International Space Station. One such contaminant gas, formaldehyde (CH2O), is of particular concern since it is toxic in significant concentrations and emanates from a wide variety of common materials, including various foams and epoxies employed on the International Space Station. Despite the fact that these materials have been extensively tested and deemed safe by NASA and other groups, CH2O concentrations have continued to steadily increase on the space station, and present levels now exceed the SMAC value of 40 parts-per-billion for exposure durations greater than seven days. Upon learning of APOL’s unique capabilities to measure with high accuracy ambient CH2O levels three orders of magnitude lower than the SMAC level, NASA scientists immediately contacted the APOL group to seek advice and help. As a result, the APOL group formed a partnership with scientists from the University of Hartford to conduct a series of laboratory tests at the APOL facility to:

a) Measure CH2O emission rates from various foam and epoxy samples of the type employed on the space station.
b) Verify the veracity of the CH2O measurement approach (chemical badges) employed on the space station and its flow dependence. The latter is important to ascertain whether or not large differences in CH2O levels observed in different areas of the space station are real or are due to differences in badge response to different airflows.

The high sensitivity of APOL’s instrument was essential for the success of these measurements. These measurements were successfully carried out employing APOL’s airborne CH2O instrument and calibration standards. One particular type of foam used throughout the space station, melamine, was found to emit large quantities of CH2O and could account for the levels observed. Notwithstanding the high space station levels of CH2O, the emission flux concentrations from individual small foam samples tested were very low (less than 1.5 parts-per-billion and more typically an order of magnitude lower). In previous attempts to measure CH2O foam emission rates, the instruments employed could only resolve CH2O levels in the 10’s of parts-per-billion range, far too high for accurate quantification of CH2O sources.

The flow dependence of the chemical badge results was very small. However, the absolute values of the retrieved concentrations from these simple devices were nearly 100% too high when compared to APOL’s CH2O standards, which were used to test the badges. The precise verifiable accuracy of APOL’s CH2O standards was essential to these tests. A report is in preparation summarizing these findings, and NASA will devise mitigation strategies in the future based upon that report.

JEFFCO Hangar

ATD's Research Aviation Facility (RAF) staff at the Jeffco Airport continued space-planning work for the new hangar and the existing facility to prepare for the arrival of HIAPER. This new hangar can accommodate both HIAPER and the C-130, which will allow for more optimal use of space in the likely event a field project requires ATD engineers to make modifications of other aircraft in our current hangar, which was the case with the Naval Research Lab's P-3 during IHOP_2002. A contract for the design and construction of ATD's new hangar at the Jefferson County Airport was issued in January 2003. Initial design work was hampered by inadequate documentation of utility locations and property lines. Preliminary designs were completed in August. A new site lease showing corrected property lines was signed in August. Construction of the pre-fabricated steel hangar was initiated in late September. Jefferson County approved the excavation permit in late September. Excavation of the site will begin in mid-October.

Real-Time Display and Coordination Center (RDCC)

ATD staff provided an extraordinary level of real-time data and communication service to BAMEX: real-time high-bandwidth communications among mobile and fixed sites; data integration to provide data set overlays, for example of aircraft tracks on radar images, radar images on satellite images, etc.; real-time Internet communications (in a '"chat"-type format) with three aircraft and project particpants; and real-time data (not just image) access and backup. In addition, ATD staff supplied all of the day-to-day computer networking needs for the BAMEX project office at MidAmerica Airport near St. Louis, Missouri.

BAMEX operations depended on daily planning coordinated among sites, quick data analysis with multiple sensor quality control, and real-time communication with and control of ground and aircraft resources to track last-minute changes in flight plans and timing of launches/drops of observing systems. Those functions could not have occurred without ATD support and services. Network, wireless, and satellite technologies, coupled with rapid affordable data storage and multiplatform data display tools, allow ATD to provide these services—information technology applied to real-world research. Most large field projects now require these kinds of information and coordination capabilities.

Driftsonde

During FYO3 ATD achieved all Phase I objectives of the Driftsonde development. ATD launched three additional (two previous flights were made in FY02) development test flights from the Global Solutions for Science and Learning (GSSL) Flight Facility in Tillamook Oregon. The table below outlines the major details and objectives of those three flights.

As the table shows, ATD achieved significant improvements both in duration and altitude for Flight # 5, launched on September 2, 2003 (below left.) The figure below right shows its flight path.

A major objective for Flight #5 was to operate for multiple days with auto-ballasting over the ocean while dropping several NCAR sondes to identify any multi-path telemetry problems from reflections off the ocean.

The only way an over-the-ocean flight could be accomplished from Tillamook was to use a larger balloon (2220 cubic meter volume balloon instead of a 363 cubic meter balloon) that could lift the ATD payload high enough to reach the stratospheric easterly winds above ~22 kilometers (45 mb). Three day/night auto-ballasting cycles were performed with an additional fourth auto-ballast cycle occurring when the balloon went over some cold clouds on day two (left figure). The cold clouds reduced the amount of infrared energy coming from the ocean surface causing the balloon to lose heat and therefore volume and lift. Eight NCAR GPS sondes were dropped during the three-day mission.

Intelligent Sensor Array (ISA)

Last spring ATD, under NCAR’s Advanced Observing Systems Initiative, began to develop a new environmental and meteorological observing system to keep NCAR at the forefront of geoscience observing system technology. This technology is called the ISA or Intelligent Sensor Array.

Currently, due to limitations resulting from long deployment cycles, ATD supports only ten stand-alone ground systems and a few instrumented tower levels at any one time, most often for only a single project at a time. Although current surface measurement systems, such as the Integrated Surface Flux system, often serve as calibration standards for surface weather installations at fixed sites, recent measurement episodes during dedicated field projects as well as efforts to establish and sustain longer-term observational capabilities reveal two profound needs: 1) more measurements at more points, and 2) a way to connect and scale point measurements to model grid scales and to satellite remote sensing scales. These needs inspired the development of an intelligent sensor array that would allow multiple sensors in an array and multiple arrays to be used at any one time, thereby enabling advanced inter-process and cross-ecosystem sensing capabilities.

The initial design goals for the ISA are quick, flexible deployment options, the option for several types of sensors at a given node, the use of modular and largely off-the-shelf components with flexible measurement capability over varying scales with self-organized wireless communication linked to a self-organized wired network.

To accomplish these goals, ATD partnered with UCLA’s Center for Embedded Network Sensing and the US Park Service in Glacier National Park, to design, evaluate and explore the capabilities of prototype multi-scale meteorological and environmental sensor arrays. Under this partnership, ATD wrote and submitted a proposal to NSF under the Smart Sensor Array Initiative for environmental process exploration to design and develop the array.

This spring, ATD began work on a prototype with the following goals :

1. A functioning 3-tier system demonstrating the desired spatial ranges at each tier
2. Bi-directional communication within and cross-tiers with event driven recognition
3. Handling of real-time data flow within and cross tiers

Prototypes of the ISA consist of a three-tiered design and infrastructure architecture capable of combining meteorological and environmental sensing capabilities with fine scale arrays (deployed on meter to 10’s-of-meter scales) nested within mesoscale arrays (deployed on 100 meter to 10 kilometer scales) connected by network nodes (wired Ethernet, radar or satellite) with power, and signal processing(intelligence) capabilities appropriate to each level, all connected by an integrated and scalable software framework with bi-directional within-tier and cross-tier communications (below).

To date, hardware has been evaluated and purchased for each tier level including a subset of sensors to make standard meteorological measurements, and communications for meso-scale and micro-scale ranges. Within and cross-tier communication capabilities have been verified and tested at mid-range and micro-range using a MaxStream Antenna and micro-range RF . The software effort has focused on the implementation of UCLA’s Directed Diffusion software code to handle the flow of information between platforms for event recognition and response, as the figure below shows.

Directed Diffusion is a distributive processing method that influences how data is moved through the array. It interacts with event routing by facilitating modules that process data as it moves through the network. Matching rules control which filters are triggered and how data sources and sinks are related.

Bow Echo and MCV EXperiment (BAMEX)

The Bow Echo and MCV Experiment (BAMEX) took place from 19 May to 6 July 2003 in the central United States. The project focused on lifecycles of mesoscale convective systems, primarily bow echoes and MCVs, with the goal of understanding and improving prediction of mesoscale as well as cell-scale processes that produce severe surface winds and heavy rains.

BAMEX was the first field deployment that claimed an entire airport for science operations. Three aircraft, the NRL P3, one of the NOAA P3s and a leased Learjet from Weather Modifications Inc. were operated out of MidAmerica airport near the town of Mascoutah, IL. The two turboprops were equipped with dual Doppler radar capability, the Lear carried the NCAR dropsonde system to map the mesoscale evolution of long-lived MCSs. On the ground, the GBOS consisting of two mobile GLASS systems and the University of Alabama at Huntsville MIPS system were used to augment airborne radar coverage by documenting the thermodynamic structure of the PBL.

Despite a slow start and lack of appropriate weather in the early weeks of the project, the NLR P-3 with NCAR’s ELDORA radar flew 18 Intensive Observing Periods, spending 134 hours in Midwestern airspace. The MGLASS drove 13,733 miles in the 7 weeks of operations, launching close to 300 sondes, while the Learjet dropped 468 sondes in the same time frame. For more information, please see the news release published by the National Center for Atmospheric Research.