Lagrangian air mass tracking with smart balloons during ACE-2

A 3rd-generation smart balloon designed at National Oceanic and Atmospheric Administration, Air Resources Laboratory Field Research Division, in colla boration with the University of Hawaii, was released from ship-board during the recent Second Aerosol Characterization Experiment (ACE-2) to provide L agrangian air-mass tracking data. ACE-2 is the 3rd in a series of field exp eriments designed to study the chemical, physical, and radiative properties and processes of atmospheric aerosols and their role in climate and is org anized by the international global atmospheric chemistry (IGAC) program. Th e adjective small in the title of this paper refers to the fact that the bu oyancy of the balloon automatically adjusts through the act of pumping air into or releasing air from the ballast portion of the balloon when it trave ls vertically outside a barometric pressure range set prior to release. The smart balloon design provides GPS location, barometric pressure, temperatu re, relative humidity, and other data via a transponder to a C130 research aircraft flying in the vicinity of the balloon. The addition of 2-way commu nication allows interactive control of the balloon operating parameters by an observer. A total of 3 cloudy Lagrangian experiments were conducted duri ng the ACE-2 held program which lasted from 16 June through 26 July 1997. T his paper reviews the design and capability of the smart balloons and their performance during the ACE-2 Lagrangian experiments. Future development an d applications of the technology are discussed.