COSMIC Update and Highlights 8 November
COSMIC launch picture provided by Orbital Sciences Corporation All six satellites stacked and launched on a Minotaur rocket Initial orbit altitude ~500 km; inclination ~72° By Dec 2007 will be maneuvered into six different orbital planes for optimal global coverage (at ~800 km altitude) Launch on April 14, 2006 Vandenberg AFB, CA
Mariner IV at Mars July 1965 Planetary Radio Occultation Radio occultation was first applied to Planetary atmospheres by teams at Stanford U. and NASA/JPL
GCOS Implementation Plan for the Global Observing System for Climate October 2004 Action A20 (AF13): GPS RO measurements should be made available in real time, incorporated into operational data streams, and sustained over the long-term. [ GCOS-92, WMO/TD No. 1219, October 2004] First ever constellation of RO satellites! Major international interest!
GPS Occultation Basic measurement principle: Deduce atmospheric properties based on precise measurement of phase delay and amplitude.
Global observations of: Pressure, Temperature, Humidity Refractivity Ionospheric Electron Density
GPS Radio Occultation (RO) Data Climate: –Characterize climate, its variability and change –Evaluate global climate models and analyses –Monitor climate change and variability with unprecedented accuracy- world’s most accurate thermometer! Meteorology: –Improve global weather analyses, particularly over data void regions such as the oceans and polar regions –Improve skill of global and regional weather prediction models –Improve understanding of tropical, midlatitude and polar weather systems and their interactions Ionosphere: –Characterize global electronic density distribution –Observe the interactions among the upper stratosphere, mesosphere and ionosphere –Improve the analysis and prediction of space weather.
Heritage of FORMOSAT-3/COSMIC July 1965 Mariner IV mission to Mars ~1988 JPL proposes RO mission for Earth 1993 UCAR GPS/Met proposal to NSF UCAR GPS/MET-1 st RO mission for Earth 1996 Concept of ROCSAT-3/COSMIC originated in Taiwan (UCAR and NSC) 1998 First tech support agreement NSPO 2001 FORMOSAT-3/COSMIC project begins 2006 Launch April 14, 2006
A COSMIC Education Module A joint effort by COMET and COSMIC. It covers: - Basics of GPS radio occultation science - Applications to weather, climate, and ionosphere - COSMIC Mission description
* Select the 'Sign Up ' link under COSMIC Accept data use agreement * Enter information: Name, Address, , user_id, Password, planned use of data An will be sent within 2-3 business days to indicate access has been granted. COSMIC Data Access More than 350 users have registered
RO-Research to Ops RO data will be valuable to: –Weather prediction –Climate monitoring and analysis –ionospheric research and space weather forecasting –Complement other satellite observing systems Need plan for transition from research into operations COSMIC II
Characteristics of GPS RO Data Limb sounding geometry complementary to ground and space nadir viewing instruments Global 3-D coverage 40 km to surface High accuracy (equivalent to <1 K; average accuracy <0.1 K) High vertical resolution (0.1 km surface - 1km tropopause) Only system from space to resolve atmospheric boundary layer All weather-minimally affected by aerosols, clouds or precipitation Independent height and pressure Requires no first guess sounding Independent of radiosonde calibration No instrument drift No satellite-to-satellite bias Compact sensor, low power, low cost
Current Constellation Oct. 1, 2007
Sunday May 6, 2007 Global coverage in all weather 2111 soundings
A typical RO sounding showing very sharp tropopause. No other instrument from space can provide this high vertical resolution.
The Effect of Open Loop Tracking
Penetration of setting/rising soundings More than 60% of all soundings penetrate to at least 1 km
Detecting the Atmospheric Boundary layer with RO
Global Distribution and Height of Atmospheric Boundary Layer
Precipitable water estimated from COSMIC GPS RO data
Weather Analysis and Prediction
Leading Weather Center Newsletters
Impact study with COSMIC 500 hPa geopotential heights anomaly correlation (the higher the better) as a function of forecast day for two different experiments: –PRYnc (assimilation of operational obs ), –PRYc (PRYnc + COSMIC) We assimilated around 1,000 COSMIC profiles per day Results with COSMIC are very encouraging
Southern Hemisphere Forecast Improvements from COSMIC Data Sean Healey, ECMWF
Using COSMIC for Hurricane Ernesto Prediction Without COSMIC With COSMIC Results from Hui Liu, NCAR
Using COSMIC for Hurricane Ernesto Prediction GOES Image With COSMIC GOES Image from Tim Schmitt, SSEC
Climate
abc We can use RO data to calibrate other instruments N15, N16 and N18 AMSU calibration against COSMIC
Comparison of PW data from COSMIC and global analyses PW retrieved from COSMIC GPS RO data using NCEP or ECMWF analysis as first guess PW derived from NCEP or ECMWF analyses
Comparison of SSM/I retrieval with COSMIC
COSMIC - CHAMP Mission Comparison
Ionosphere and Space Weather
Comparisons with ISR data [Lei et al., submitted to JGR 2007]
Scintillation Sensing with COSMIC No scintillation S4=0.005 Scintillation S4=0.113 GPS/MET SNR data Where is the source Region of the scintillation?
COSMIC Follow-On Mission NRC Decadal Survey Recommendation for NOAA: “Implement an operational radio occultation satellite constellation following COSMIC”
Improvements expected from “COSMIC II” More receivers per launch - ~20 kg micro-satellites More soundings per receiver - added Galileo / Glonass tracking capability Higher density of profiles - data useful for global and mesoscale models Lower data latency - Can be reduced from 2-3 hours to 5 minutes (especially important for Space Weather) Improved tracking and more antenna gain - better data in the lowest moist troposphere Continued, longer, stable climate record Possibility of added capability like monitoring of reflections from sea surface and ice sheets
COSMIC Follow-On Mission Possible Future Coverage of Daily Soundings
Coverage of possible future constellations 6 RO constellation (COSMIC) 28 GPS Add 24 GLONASS Add 30 Galileo
Coverage of possible future constellations 12 RO constellation 28 GPS Add 24 GLONASS Add 30 Galileo
Coverage of possible future constellations 24 RO constellation 28 GPS Add 24 GLONASS Add 30 Galileo
Occultation Sounding Statistics # of LEO’sTransmitters Total number of soundings Average horizontal spacing [km] Average number of soundings in 500km/500km box [#] 6GPS GPS+GLO GPS+GLO+GAL GPS GPS+GLO GPS+GLO+GAL GPS GPS+GLO GPS+GLO+GAL GPS GPS+GLO GPS+GLO+GAL
RO-Research to Ops RO data will be valuable to: –Weather prediction –Climate monitoring and analysis –ionospheric research and space weather forecasting –Complement other satellite observing systems Need plan for transition from research into operations COSMIC II
The Future FORMOSAT-3/COSMIC is Exceeding Expectations Need to complete mission Need to plan for next mission COSMIC launch picture provided by Orbital Sciences Corporation
Summary COSMIC a successful Taiwan-U.S. project COSMIC launched on time and within budget (~$100M mission) Inexpensive way of obtaining atmospheric soundings in all weather High accuracy, precision and vertical resolution demonstrated Already positive impact on weather models Observations of tropical boundary layer from space for first time Only observing system to provide information on ionosphere, stratosphere and troposphere Will have major impact on climate monitoring-world’s most accurate, precise and stable thermometer! Free and open exchange of data—more than 600 users from 42 countries