Driftsonde Flights during AMMA Stratospheric balloons to study African monsoon and formation of cyclones Driftsonde Flights during AMMA Stratospheric balloons to study African monsoon and formation of cyclones National Center for Atmospheric Research (NCAR) Centre National d’Etudes Spatiales (CNES) [French National Center for Space Studies] Terry Hock, Dave Parsons, Hal Cole, Jack Fox, Joe VanAndel, Keith Romberg NCAR/EOL Nov. 2, th International Conference on Mesoscale Meteorology and Typhoon

Cost-effective dropsonde observations of wind, temperature, and humidity to fill critical gaps in coverage over oceanic and remote artic and continental regions over days to weeks. Driftsonde Concept

Support of the THORPEX International Science and Implementation Plans for demonstration tests of new technologies for the delivery of in-situ sensing The tests were supported by CNES for the ballooning (French Space Agency) Support within the US by NCAR and NOAA/THORPEX for the driftsonde gondola and new dropsondes 8 Balloon flights 24 to 40 Miniture Dropsondes per balloon flight Launch Location Zinder, Niger Flight Operations Center Paris and Boulder Engineering team effort between CNES & NCAR Flights 10+ days CNES Delveloped Super Pressure Balloon and Flight Control System NCAR Developed Driftsonde Gondola System, Miniture Dropsonde and Ground Sounding Software AMMA Driftsonde Project Goals

Zinder Team Philippe Cocquerez, Stéphanie Vénel (CNES); Terry Hock, Jack Fox,, Keith Romberg (NCAR) Paris Team Philippe Drobinski (IPSL/SA); Dave Parsons, Joe VanAndel, Hal Cole (NCAR) Boulder Team Dean Lauritsen, Charlie Martin, Gary Granger, Dennis Flanigan, (NCAR) AMMA Driftsonde Team

Zinder Flight Operations Final Testing Payload Sonde Loading Balloon Inflation

Zinder Niger Driftsonde AMMA Launch Location Zinder, Niger

Flight #1 Driftsonde Launch August 28 th 2006

MIST Design Criteria & Motivation - Low cost (current aircraft dropsondes cost >$700) - Small (credit card size) - Lightweight (Gondola to carry 80 sondes) - Pressure derived from GPS & hydrostatic equation (using known launch pressure) - Operate at -70º C (20km altitude) MIST Sonde Specification Size: 4.62 cm diameter, length cm Weight: 145 grams Fall rate ~10 m/s at surface, cone parachute Sensors: Temperature, Humidity, Winds & Position - 50 mil Thermsitor - Humicap w/temperature sensor for substrate -16 channel GPS receiver Sensor sample rate 0.5 secs Remote control Power On & Sonde Release Miniature In-situ Sounding Technology (MIST Sonde developed at NCAR) GPS Receiver (16 channel) Temperature Sensor (50 mill bead thermistor) Humidity Sensor (humicap w/substrate temperature) temperature) Transmitter (400 MHz) GPS Antenna 2 Microprocessors

Lithium Batteries Iridium Satellite Transceiver NCAR System Electronics MiniatureDropsonde Lower Part of Gondola Gondola Electronics- sonde receiver system Upper Part of Gondola

AMMA Driftsonde Flights Flight # Launch Date TerminatedFlight Duration (Days) Notes 1Aug 28Sep sondes 2Aug 29Aug Sondes (Electronic Failure) 3Sep 1Sep sondes 4Sep 4Sep Sondes 5Sep 6Sep Sondes 6Sep 9Sep Sondes 7Sep 12Sep sondes (Balloon Failure) 8Sep 15Oct Sondes 6 successful missions from the 8 Driftsondes launched

Predicted Flight Trajectories Driftsonde Flights Sonde release

Driftsonde data Driftsonde 3 in the vicinity of tropical cyclone Florence Tropical cyclone Florence Sondes released from driftsonde #3

Driftsonde data Driftsonde 4 in the vicinity of tropical cyclone Gordon Sondes released from driftsonde #4 Tropical cyclone Gordon

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