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0 Earth Observation with COSMIC
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1 COSMIC at a Glance l Constellation Observing System for Meteorology Ionosphere and Climate (ROCSAT-3) l 6 Satellites launched in late 2005 l Orbits: alt=800km, Inc=72deg, ecc=0 l Weather + Space Weather data l Global observations of: ●Pressure, Temperature, Humidity ●Refractivity ●TEC, Ionospheric Electron Density ●Ionospheric Scintillation l Demonstrate quasi-operational GPS limb sounding with global coverage in near-real time l Climate Monitoring l Geodetic Research
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2 COSMIC Status
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4 Figure: T. Yunck
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6 Radio occultation for Climate
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7 COSMIC high resolution profiles Profile the (sporadic) ionospheric E-layer with ~1-km vertical resolution Area dominated by noise - used for noise calibration of profile Area affected by noise - profiles are noisy and/or affected by climatology Highest quality profiles 5-30 km Some profiles affected by boundary layer effects (super refraction)
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8 GPS RO Minus NCEP 50 mb S. hemisphere
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9 Climate Change and Geopotential Heights
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10 Climate change effect on Temperature and Bending Angles Temperature change due to 2xCO2 Bending Angle change due to 2xCO2 Radio occultation (RO) bending angles are a potentially better indicator for a stratospheric climate signal than RO temperatures.
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11 Climate Research with RO Data Investigate potential biases in RO time series Investigate use of geopotential height, bending angles, or refractivity for climate studies Climate process studies (Bill Randel’s work)
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12 GPS Operational Tracking Scenario ApplicationAltitude Range (km) AntennaSampling Rate (Hz) Plasmasphere> 800POD ant.1 Ionospheric Profiling140 < Alt < 800POD ant.1 Ionospheric Profiling and Scintillation 60 < Alt < 140Limb ant.50 - 100 n GPS receiver shall measure GPS L1&L2 phase and amplitude for (1) ionospheric profiling; (2) plasmaspheric monitoring; (3) scintillation studies COSMIC S/C With Antennas POD antennas @ 1 Hz Limb Antennas @ 50-100 Hz
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13 Electron Density Profile Vertical Profile of electron density from GPS/MET
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14 TIP Payload n TIP measures nighttime FUV emission of neutral atomic oxygen n TIP and GPS data can be processed together for improved ionospheric profiling n Radiative recombination: O + +e - O+h –135.6 nm produced by radiative recombination of O + ions and electrons –O + and e - densities equal in the F-region –135.6 emission intensity proportional to electron density squared –Simple algorithm relates electron density to 135.6 nm intensity measured by TIP n Aurora: O+e - O +e - +h –135.6 nm produced in aurora through electron impact excitation –TIP can determine auroral boundaries
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15 CERTO / TBB Concept Irregularity Orbit Receiver CERTO Beacon OBJECTIVE –Provide Multi-Scale Description of the Ionosphere Beacon to Ground Total Electron Content (TEC) using Differential Phase and Faraday Rotation Maps of Structured and Quiescent Plasma Environment Based on Phase and Amplitude Scintillations Description –Three Frequency Radio Beacon (150.012, 400.032, 1066.752 MHz) Radiating Phase Coherent, Continuous Wave Transmissions –Differential Phase Receivers on the Ground Recording Phase and Amplitude. –Images Obtained by Tomographic Processing of Data
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16 CDAAC Ionospheric Data Products Data LevelFile TypeDescriptionFile Content Level0tbbLv0CERTO/TBB data file for station Time, SNR, , S4, station position, LEO orbit, TEC, TEC error estimates Level1atipLv1TIP RadiancesTime, LEO pos/vel, pointing, Radiance, Calibration, Radiance error estimate Level1bionPhs1 Hz biased TEC file for ionospheric occultations (altitude > 60km) Time, SNR, LEO Orbits, GPS Orbits, biased TEC, TEC error estimate Level1blosPhs1 Hz biased TEC file for non-occulting linksTime, SNR, LEO Orbits, GPS Orbits, biased TEC, TEC error estimate Level1batmPhs50 Hz excess phase file for atmospheric occultations (alt < 140km) Time, SNR, LEO Orbits, GPS Orbits, L1 excess phase, L2 excess phase, S4 Level2ionPrfElectron Density Profile computed with Abel inversionLatitude, Longitude, Altitude, Electron Density, ED error estimate Level2iocPrfElectron Density Profile computed with additional TIP data as constraint Latitude, Longitude, Altitude, Electron Density, ED error estimate
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17 Ionospheric Research with COSMIC Data n We are talking with NCAR HAO to identify COSMIC data products that will be most beneficial to ionospheric research community n Calibration/Validation of other ionospheric instruments n Calibration, improvement, and validation of physics based models of ionosphere n Studies of scintillation (plasma bubbles) n Ionospheric climatology n Studies of plasmaspheric depletion and refilling during and after storms n Ionospheric enhancements and depletions during storms n Gravity wave studies n Traveling Ionospheric Disturbances
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18 InputDataInputData CDAAC CDAAC NESDISNESDIS GTS NCEP ECMWF CWB UKMO Canada Met. JMA BUFR Files WMO standard 1 file / sounding Getting COSMIC Results to Weather Centers This system is currently under development by UCAR, NESDIS, + UKMO Data available to weather centers within < 180 minutes
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19 Summary COSMIC is on track to launch in ~1 year Will provide data for a wide range of climate, weather and space weather investigations COSMIC data Collaboration on the optimal use of these data at UCAR/NCAR provide a rich opportunity for our organization Hope to identify scientific opportunities and programmatic approaches to them
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20 Effect of 2xCO2 on Temperature and GPH
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21 GPS RO Minus ECMWF 50 mb S. hemisphere
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22 Ionosphere GPS/MET - Abel Inversions Matches = 2183 mean = 0.001 MHz std = 0.81 MHz Matches = 370 mean = -9 km std = 39 km
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23 Scintillation Sensing with GPS RO GPS/MET No scintillation S4=0.005 Scintillation S4=0.113
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24 Example GPS/MET Sounding Main Features of RO Soundings High vertical resolution (0.1 - 1 km) All weather (no cloud/rain effect) Long-term stability (for climate) Profiling from 800 km - surface
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25 GAIM Assimilates Multiple Data Sources Bottomside N e Profiles from Ionosondes In Situ DMSP Satellite Measurements Ground-Based GPS TECs TECs Between Ground Stations and Low-Earth-Orbiting Satellites With Radio Beacons Satellite Occultation Data Line-of-Sight UV Emissions from DoD Satellites The Data Must be Real-Time or Near Real-Time.
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26 Effects of CO2 increase on climate change simulated by NCAR Climate System Model (CSM) Vertical cross sections of zonally-averaged model temperature changes averaged over 20 years (years 60-79) in NCAR Climate System Model in which carbon dioxide alone is increased by 1% per year (Meehl et al., 1998).
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