Formosat3 / COSMIC: Constellation Observing System for Meteorology, Ionosphere and Climate Mission Status and Data Distribution Unidata Policy Committee Meeting 29 Oct. 2007 COSMIC is called Formosat-3 in taiwan. Taiwan’s NSPO is the primary sponsor (80%) and mission operator of COSMIC.

Current Constellation Oct. 28, 2007

The LEO tracks the GPS phase while the signal is occulted to determine the Doppler LEO vleo vGPS Tangent point The velocity of GPS relative to LEO must be estimated to ~0.2 mm/sec (20 ppb) to determine precise temperature profiles … so once the orbits have been determined well it is possible to determine atmospheric profiles. The lower right panel on this slide shows a birds-eye view of the CHAMP satellite in LEO. The white line indicates the ray to the GPS which is not shown and the while dot shows the location of the tangent point introduced in the top left panel. As the tangent point descends through the atmosphere the temperature profile is shown in the little panel to the right of the globe. The temperature profiles is obtained in post processing.

Evolving COSMIC Constellation Temperature [C] at 100 mb (16km)

Comparison of collocated Profiles Fig. 7a: Vertical profiles of “dry” temperature (blue and red lines) from two independent receivers on separate COSMIC satellites (FM-3 and FM-4) on 3 August, 2006 The satellites were approximately 5 seconds apart, which corresponds to a distance separation at the ray tangent point of about 1 km. The latitude and longitude of the soundings are 21.8°S and 32.9°W. The black line (GFS) is the NCEP analysis of temperature interpolated to the time and location of the COSMIC soundings.

Animation of COSMIC determined water vapor at 1 km altitude for several months

Statistical comparison of FM3-FM4 Soundings separation < 10 km 0.2% precision between 10-20 km Difference for pairs of GPS RO measurements (FM3-FM4) with tangent point separation less than 10 km. The blue line shows the number of pairs of nearby soundings with height. The red line shows the mean difference, and the green lines show the standard deviations of the differences plotted around the mean. The RMS difference of refractivity between 10 and 20 km altitude is less than 0.2%, Schreiner et al. 2007

Detection Of Boundary Layer With RO Figure 5. Examples of COSMIC RO-retrieved bending angle and refractivity profiles in the sub-tropics, showing sharp ABL top (bending angle is a function of ray tangent height) compared to ECMWF analyses.

ABL Height Observations During COSMIC Year 1 (bending angle gradient > 1e-2 rad/dH, height < 3 km)

Leading Weather Center Newsletters

Using COSMIC for Hurricane Ernesto Prediction With COSMIC Without COSMIC Effect of assimilation of COSMIC data on Hurricane prediction. Left with COSMIC, right w/o COSMIC. Integrated cloud liquid from model output is shown in grey shades. Results from Hui Liu, NCAR

Using COSMIC for Hurricane Ernesto Prediction With COSMIC GOES Image .. . And now compreed to the GOES image of the same storm GOES Image from Tim Schmitt, SSEC

6-Year RO Temperature Anomaly Trend Tropics, 200 mb (~12 km)

Preliminary 2002 - 2007 RO Temperature Trends (12, 17, 21, 27 km) Ramaswamy, V., M-L. Chanin, J, Angell, J. Barnett, D. Seidel, M. Gelman, P. Keckhut, Y. Koshlekov, K. Labitzke, J-J. Lin, A. O'Neill, J. Nash, W. Randel, R. Rood, K. Shine, M. Shiotani, and R. Swinbank, Stratospheric temperature trends: Observations and model simulations, Reviews of Geophysics, 39, 71-122 (2001). The large cooling in polar regions may be related to large variability in this region. Chanin et al., 2001: 0.75 C/decade cooling in 20-35 km NH QBO not removed (significant for 6 years) Need to add slope uncertainties

Number of Profiles (Oct. 28, 2007) 752,000 Neutral Atmosphere 1,006,000 Ionosphere

NESDIS CDAAC Getting COSMIC Results to Weather Centers Operational Processing TACC JCSDA NCEP Input Data NESDIS CDAAC ECMWF CWB GTS BUFR Files WMO standard 1 file / sounding UKMO JMA Science & Archive Canada Met. NRL Data available to weather centers within < 180 minutes of on-orbit collection

Processing Center Status 30 TB downloaded (100-150 Gbytes/day) 80% of soundings delivered in < 3 hours All data post-processed with CDAAC 2.0 software (until June 2007) New firmware currently tested at JPL

619 data users from 42 countries are registered COSMIC Data Access 619 data users from 42 countries are registered http://www.cosmic.ucar.edu * Select the 'Sign Up ' link under COSMIC Accept data use agreement * Enter information: Name, Address, email, user_id, Password, planned use of data An email will be sent within 2-3 business days to indicate access has been granted. COSMIC data are open to public, and freely available. Use of COSMIC data requires registration-a simple process. More than 350 users have registered as of November 1, 2006.

COSMIC Data Availability Data opened up to public in July 2006 All Data (including raw data) available at the end of each day Real-time products (profiles of bending, refractivity, …) in WMO standard format available via the GTS Post-processed data for climate research will be updated every few months Data use agreement with NSPO required for use of all data and data products (via TACC or CDAAC website)

COSMIC Data Policy Real-time data (raw data, excess phase data, etc.) available upon approval of letter request to NSPO director and UCAR president All requests have been approved Data policy must be revised for distribution of near-real-time data products to Unidata community Users should still register

Summary Deployment to final constellation almost complete (raising FM1) Large amount of high quality data resulted in: 600+ registered data users ~80% of soundings penetrate to lowest km of atmosphere Operational use by world’s leading weather centers Demonstration of 0.2% precision of RO observation in 10-20 km height range Extened climate record Remote sensing of global ABL / Convection Improvements to ionospheric models Global scintillation observations COSMIC presently faces several difficulties Frequent unexplained drops in SNRs from GPS antennas Lost 1 solar panel on FM2 Stuck solar array drive on FM3 No communications presently with FM6 Chances for a Follow - on mission would benefit from wider user community