Evolution in Design of a Smart Balloon
for Lagrangian Air Mass Tracking

Randy Johnson
NOAA, Air Resources Laboratory, 
Field Research Division, Idaho Falls, Idaho 83402
email: randy@noaa.inel.gov
Steven Businger
University of Hawaii, Honolulu, Hawaii 96822
email: businger@soest.hawaii.edu


A series of balloons, designed at NOAA Air Resources Laboratory Field Research Division, was released from ship-board during three recent atmospheric chemistry field experiments to provide Lagrangian air-mass tracking information. The position of the balloons was monitored via an onboard GPS receiver and transmitted via radio to a research aircraft operating in the vicinity of the balloons. In total, seven successful Lagrangian experiments have been carried out, two each during the ASTEX* and ACE-1* field programs and three during the ACE-2* field program. This poster reviews and contrasts the design and capability of the Lagrangian balloons and their performance during the field experiments.

Figure 1Figure 2aFigure 2bASTEX- was held in the Azores Islands to study the evolution of clean air emanating fron the north Atlantic. The ASTEX tetroon is a simple constant-level balloon made of Mylar (trademark) with a tetrahedral shape to facilitate construction (Fig. 1) (Businger et al. 1996). The advantage of these tetroons is their small size, ease of deployment, and low cost. Only GPS position data are available in this design. The disadvantage of the ASTEX tetroon is the lack of ability to compensate for the impact of precipitation loading and radiation on the buoyancy of the tetroons (Fig. 2a and Fig 2b).

Figure 3ACE-1 - The ACE-1 design of Lagrangian marker tetroon includes control of balloon lift by the action of a pump and release valve on an internal pressurized ballast bladder (Fig. 3) (Johnson, Carter, and Businger 1998, Businger et al. 1998). This design, referred to as a smart tetroon design, allows the tetroon buoyancy to automatically adjust when the tetroon travels vertically outside a range of pressures set prior to release. Figure 4bFigure 4aThe ACE-1 deployment in the vicinity of Tasmania, Australia, was the first for the smart tetroon design (Fig. 4a and Fig 4b). The ACE-1 tetroons provided GPS location, barometric pressure, air temperature, relative humidity, and tetroon status data transmitted via a transponder to a receiver aboard the NCAR C130 research aircraft flying in the vicinity of the tetroons to study the evolution of clean air. These data provide tetroon location, meteorological information on the air parcel and data to help understand the operation of the smart balloons. The ACE-1 tetroon design proved to have insufficient dynamic lift range to overcome the combined impact of water loading and radiational cooling at night, causing the tetroons to descend near the surface until after sunrise (Fig. 4a).

Figure 5Figure 6ACE-2 - Significant design improvements were incorporated into the second-generation smart balloon (Fig. 5), deployed during ACE-2 field program held between the coast of Portugal and the Canary Islands to study the evolution of polluted air emanating from Europe (Fig. 6a) (Johnson, Carter, and Businger 1998). These improvements include (i) a stronger outer shell to significantly increase dynamic lift range, (ii) two-way communication with the balloon to allow interactive control of the balloon operating parameters by an observer, and (iii) a spherical design to reduce exposure to precipitation. In addition to the variables transmitted by the ACE-1 tetroon, the ACE-2 balloon provides balloon temperature, balloon superpressure, and solar radiation data.

Figure 6The success of the ACE-2 balloon in maintaining altitude despite condensation loading and radiational effects is noteworthy (Fig. 6b). The stronger balloon shell provides an order of magnitude increase in dynamic lift range over the ACE-1 design. The altitude control works during night and day even when the wetness sensor shows condensation on the surface of the balloon.


The second-generation smart balloon design provides the means to track a parcel of air at a chosen altitude by varying the density of the balloons as environmental conditions demand. The dynamic range afforded by the high strength spherical shell in the ACE-2 design allows the balloon to remain within desired altitude operating limits despite the impacts of condensation, light precipitation, and radiative cooling. A suite of balloon-borne instruments can provide useful in situ and radiometric meteorological data, and two-way commun-ication with the balloon allows interactive control of the balloon operating parameters by an observer. The available in situ data combined with the balloon's dynamic range enable the balloon transponder to be programmed to remain at a constant altitude, to follow an isobaric or isentropic surface, or to perform soundings. These capabilities and the economical cost of the design make the smart balloon an attractive platform for a range of applications in atmospheric chemistry and mesoscale meteorology. Future improvements in the design and deployment strategy are focused on making the smart balloon a platform for studying storms. For example, to provide critical protection from the elements, a transponder design change that allows it to fit inside the balloon is being considered

* The Atlantic Stratocumulus Transition Experiment/Marine Aerosol Gas Exchange (ASTEX/MAGE) field project, and the first and second Aerosol Characterization Experiments (ACE-1, ACE-2).


We are grateful to Harvey Killian, Shane Beard, Steven Chiswell, Mark Geldmeier, and John Heyman for assistance in the field. Roger Carter provided programing support for the transponder design. Nancy Hulbirt, Annette Baerman, and Karsten Suhre contributed to the graphics. This research is a contribution to the International Global Atmospheric Chemistry (IGAC) Core project of the International Geosphere-Biosphere Programme (IGBP) and is part of the IGAC Aerosol Character-ization Experiments (ACE). This work is supported by the National Science Foundation under grants ATM94-19536 and ATM96-10009 and ONR grant N00014-92-J-1285


Web layout: Ray Tanabe
2 May 1998
Updated by Derek Funayama
19 August 2002

For more information, contact:

Dr. Steven Businger
University of Hawaii, Dept. of Meteorology
2525 Correa Road, HIG Room #350
Honolulu, HI 96822
Email: businger@soest.hawaii.edu