The NCAR Driftsonde gondola is a community designed, autonomous platform for the deployment of MIST (Miniature In-Situ Sounding Technology) dropsondes over oceans and remote polar and continental regions where rawinsondes or dropsondes from other platforms are not practical. During their vertical descent from an aloft platform, various atmospheric parameters are collected by the MIST sondes and transmitted to one or other satellite receivers, for both research and operational forecasting needs.
An opportunity to deploy a series of up to 50 sondes in a full field NASA ULDB platform launched over the Antarctic continent arises from NASA investigators (from the Columbia Scientific Ballooning Facility, Palestine, TX) conducting pre-production tests of the development of their unique long duration balloon platform (ULDB). The ULDB is of an advanced super pressure design, and uses a pumpkin shaped, closed volume (constant altitude) shape to achieve flights of up to 100 days duration, significantly longer than any comparable balloon flights, and positionable up to altitudes of ~ 30.5km. A full test of both technologies is to take place during the persistence of the Antarctic polar vortex late November, early December (2009), from Williams Field, McMurdo Station, Antarctica.
PTR - Potentially Transformative nature of this Research
The entire Antarctic (~10%of the earth's land surface) atmosphere is spectacularly under-sampled with respect to key lower atmospheric meteorological parameters. This impacts our ability to study and understand a range of phenomena ranging from the polar ozone hole to dynamics of the global circulation on climatological timescales. Discounting both their limitations and considerable expense, even advanced aircraft platforms are incapable of such sustained measurements. Satellites also have known limitations, including uncertainties as to their relative calibrations and validation that campaigns such as this could greatly assist. There are risk elements associated with the piggyback nature of the two technologies to be combined, yet the development of such a novel capability potentially opens up study of a number of important topics in Antarctic atmospheric studies.
The Driftsonde system was developed by NCARâ€™s Earth Observing Laboratory as an observing platform designed to release miniature dropsondes from the stratosphere over long periods of time (days to weeks). The system consists of a balloon that flies at high altitudes in the stratosphere. As the balloon drifts with the wind, it carries a gondola containing Miniature In-situ Technology (MIST) drospondes (http://en.wikipedia.org/wiki/Dropsonde). Together, the gondola and MIST dropsondes are a complete atmospheric sounding system with a satellite communications feed to the ground. When released from the gondola during research missions, the miniature dropsondes provide direct measurements of high-resolution, high quality wind, temperature, pressure and humidity profiles of the atmosphere. In July-December 2009, NCAR worked with the NASA Columbia Scientific Ballooning Facility (CSBF) to deploy NCARâ€™s Driftsonde system. The Driftsonde system flown on the NASA balloon was controlled from the ground using web based software. The gondola was fully equipped and loaded with 56 disposable MIST dropsondes. The NCAR-Driftsonde Ultra Long Duration Balloon Flight Project had two main objectives: 1) to perform an engineering test in preparation for the then-future project CONCORDIASI where 13 driftsonde systems would be in flight over Antarctica, and 2) to test the Driftsonde system with NASAâ€™s ballooning capabilities for possible future programs and collaborations. Both objectives were achieved successfully even though the balloon that driftsonde was installed on failed. Unfortunately, no sounding data were gathered, but CONCORDIASI was a greater success because of the extensive testing and engineering data collected in an extreme environment. Additionally, the engineering integration performed at the NASA Columbia Scientific Ballooning Facility (CSBF) in Texas confirmed that the driftsonde did not adversely affect the CSBF equipment, which was a main concern to the team. As part of the integration, the NCAR team developed a training protocol for the command and control webpage that is used to release dropsondes, record data and retrieve data products. In this way an additional goal to allow operation of the driftsonde over the web when it is deployed in remote locations (in the case of the CSBF, the Antarctic environment) was also achieved. The Driftsonde system proved to be a cost-effective platform for deploying the MIST dropsondes over oceans and remote arctic and continental regions, filling critical gaps in data coverage and supplementing satellite data with high vertical resolution data.