Driftsonde System Overview

Transcription

1 Driftsonde System Overview Zero-pressure Balloon Gondola (24 sonde capacity) 6 hours between drops Terry Hock, Hal Cole, Charlie Martin National Center for Atmospheric Research Earth Observing Lab December 7, 2004 OrbComm LEO Satellite First THORPEX International Science Symposium Montreal, Canada NORTH AMERICA ATLANTIC OCEAN EUROPE

2 Predictability research suggests that additional in-situ measurements in Sensitive Regions will improve predictions of high-impact weather events, these regions are often cloudy. Sensitive regions for November 2001 based on 30-day average of the NRL NOGAPS model (color coded). The contours are the 500 hpa height field. Courtesy of Alan Thorpe,Rolf Langland, and Melvyn Shapiro from THORPEX planning presentations.

3 Driftsonde Motivation Satellite based measurements: Infrared techniques have limits due to opaque cloud cover OrbComm Microwave techniques have relatively course vertical resolution LEO Satellite Zero-pressure Horizontal winds are a challenge in deep cloud layers. Balloon Driftsonde Goal Cost-effective observing system to fill critical gaps in data coverage over oceanic Gondola and remote artic and continental regions with high vertical resolution (24 sonde atmospheric capacity) profiles of: Wind Temperature Humidity made 6 hours by GPS Dropsondes. between New Satellite-based drops techniques (constituent track winds, water vapor tracking, Doppler lidar measurements in clear air) clearly have a need for in-situ measurements to evaluate and calibrate these satellite systems. NORTH AMERICA ATLANTIC OCEAN EUROPE

4 Driftsonde Operation OrbComm System requirements LEO Satellite Provide Zero-pressure Soundings with Global coverage Cost Balloon effective (Complete system is expendable) Flight duration 4-6 days Altitude mb Deploy Gondola Dropsondes on command (Targeting) or automatically (Timed) Payload (24 sonde of minimum capacity) 20 dropsondes ( 4/day for 5 days) Real-time position tracking - ATC monitoring Engineering Challenges Cost, 6 hours disposable sounding system Reliable betweenglobal satellite communications (Orbcomm, Globalstar, Iridium) Harsh dropsenvironment, temperature extremes (diurnal variations in radiation) Altitude control [zero-pressure balloon ballasting algorithms] Integration issues (GPS, Iridium, Sonde Transmitters, Receivers) Flight train launch NORTH AMERICA ATLANTIC OCEAN EUROPE

5 Driftsonde System Zero-pressure Balloon Iridium OrbComm LEO Satellite Gondola Gondola (20-40 (24 sonde capacity) ~16km 6 hours between drops mb NORTH AMERICA ATLANTIC OCEAN EUROPE

6 Simulated Driftsonde sounding coverage at one assimilation time after 5 days of deployment from launch sites along the Asian Pacific rim Initial Launch Time: 00 UTC 06 Feb launch sites Coverage at: 00UTC 11 Feb 1999 Drift Level: 100 mb Deployment Interval: 12hr Analysis Dr. Rolf Langland, Dr. Melvyn Shapiro

7 Driftsonde Components Flight train 1. Low cost polyethylene zero-pressure balloon (365 m 3 & OrbComm 2,265 m LEO Satellite 3 ) 2. Parachute Zero-pressure 3. Radar reflector Balloon 4. Aircraft Transponder 5. Gondola Embedded Computer Gondola GPS Navigation System (24 sonde Flight capacity) level PTH sensor Ballast System Lithium battery power system Iridium, global coverage 6 hours2-way satellite system between Dropsondes drops NORTH AMERICA ATLANTIC OCEAN EUROPE

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9 Flt. No. Date Zero-pressure Balloon 1 2/28/02 Gondola 2 11/14/02 5 hrs (24 sonde capacity) Driftsonde Flights Tillamook, OR Duration 4 ¾ hrs Altitude 16.9 km 16.4 km Objectives Same as Flight 1 OrbComm LEO Satellite Engineering Tests; Orbcomm communications, thermal control & evaluation, altitude control manual ballasting 3 2/10/03 6 hours between drops 4 8/19/03 22 ½ hrs 11 ½ hrs 16.4 km 17.6 km Engineering Tests; Iridium communications, Drop sondes (data system on ground), automatic altitude control, diurnal test First test flight of complete sounding system in gondola, dropped 4 sondes NORTH AMERICA 5 9/2/03 63 ½ hrs 24 km ATLANTIC OCEAN Over the ocean test, dropped 8 sondes, all systems worked well EUROPE

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15 Flight #5 9/2/03 ALTITUDE AND BALLAST DUMPED VS TIME SUNSET CLOUDS SUNSET SUNSET 20 ALTITUDE - METERS BALLAST DUMPED - KGMS /2/03 12:00 9/3/03 0:00 9/3/03 12:00 9/4/03 0:00 9/4/03 12:00 9/5/03 0:00 9/5/03 12:00 TIME - GMT Altitude Ballast Dumped

16 NSF THORPEX Briefing, D. Parsons, 11/21/03

17 Driftsonde Deployed Dropsonde Flight #5 Sept 9, 2004

18 Driftsonde Future Efforts Engineering Integrate Vaisala Radiosondes Super Pressure Balloon (eliminates Zero-pressure Balloon ballasting & reduces balloon size) Develop ground operations software for command and tracking Gondola Small (24 low sonde cost capacity) Wind & Temperature only sonde Sonde payload up to 50 sondes 6 hours between drops OrbComm LEO Satellite NORTH AMERICA ATLANTIC OCEAN EUROPE

19 Miniature In-situ Sounding Technology Zero-pressure Balloon (MIST Sonde) GPS Wind & Temperature only sonde (credit card size) Supported by NOAA/THORPEX OrbComm LEO Satellite Gondola (24 sonde capacity) 6 hours between drops NORTH AMERICA ATLANTIC OCEAN EUROPE

20 Driftsonde Future Efforts Gondola (24 sonde capacity) Possible Field Deployments AMMA 2006 Teaming with CNES launching Zero-pressure from Chad Balloon - SOP 2 Zero-pressure balloon - SOP 3 CNES Superpressure balloon 10-day flights, sondes OrbComm LEO Satellite 6 hours between drops International Polar Year NORTH AMERICA ATLANTIC OCEAN EUROPE

21 Proposed Driftsonde Operation on French CNES Stratospheric Balloons for 2006 Trajectories: 1 balloon launch per day for 1 Sept 15 Sept day duration (can go up to 20); 50 sondes per balloon