COSMIC: Constellation Observing System for Meteorology, Ionosphere and Climate Status and Results with Emphasis on the Ionosphere Christian Rocken, Stig Syndergaard, Zhen Zeng UCAR COSMIC Project FORMOSAT-3

Outline COSMIC Introduction Results –Some neutral Atmosphere Results –Ionosphere »GPS TEC Arcs »GPS Electron Density Profiles »Scintillation »Validation / Comparison to Models »TIP »TBB –Latency and Data Distribution Summary

COSMIC (Constellation Observing System for Meteorology, Ionosphere and Climate) 6 Satellites launched 01:40 UTC 15 April 2006 Three instruments: GPS receiver, TIP, Tri-band beacon Weather + Space Weather data Global observations of: Pressure, Temperature, Humidity Refractivity Ionospheric Electron Density Ionospheric Scintillation Demonstrate quasi-operational GPS limb sounding with global coverage in near-real time Climate Monitoring

The velocity of GPS relative to LEO must be estimated to ~0.2 mm/sec (velocity of GPS is ~3 km/sec and velocity of LEO is ~7 km/sec) to determine precise temperature profiles The LEO tracks the GPS phase while the signal is occulted to determine the Doppler LEO v leo v GPS Tangent point

The velocity of GPS relative to LEO must be estimated to ~0.2 mm/sec (20 ppb) to determine precise temperature profiles The LEO tracks the GPS phase while the signal is occulted to determine the Doppler LEO v leo v GPS Tangent point

COSMIC Radiosondes COSMIC Soundings in 1 Day Sec 3, Page 10

Atmospheric refractive index where is the light velocity in a vacuum and is the light velocity in the atmosphere Refractivity Hydrostatic dry (1) and wet (2) terms dominate below 70 km Wet term (2) becomes important in the troposphere and can constitute up to 30% of refractivity at the surface in the tropics In the presence of water vapor, external information information is needed to obtain temperature and water vapor Liquid water and aerosols are generally ignored Ionospheric term (3) dominates above 70 km (1) (2) (3)

6 Micro Satellites - USAF Minotaur Rocket Integration

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° Will be maneuvered into six different orbital planes for optimal global coverage (at ~800 km altitude) Satellites are in good health and providing data-up to 2200 soundings per day to NOAA Launch on April 14, 2006, Vandenberg AFB, CA

COSMIC Current Constellation

COSMIC - Final Deployment 6 Planes 71 Degrees inclination 800 Km 2500 Soundings per day Latency minutes from observation to NOAA

Some Neutral Atmosphere Results

Vertical profiles of “dry” temperature (black and red lines) from two independent receivers on separate COSMIC satellites (FM-1 and FM-4) at 00:07 UTC April 23, 2006, eight days after launch. The satellites were about 5 seconds apart, which corresponds to a distance separation at the tangent point of about 1.5 km. The latitude and longitude of the soundings are 20.4°S and 95.4°W. 00:07 UTC 23 April 2006, eight days after launch

Comparison of Pairs of COSMIC soundings with GFS analysis

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

Southern Hemisphere Forecast Improvements from COSMIC Data Sean Healey, ECMWF

Northern Hemisphere Forecast Improvements from COSMIC Data Sean Healey, ECMWF

Space Weather

GPS Antennas on COSMIC Satellites Nadir 2 Antennas for orbits, TEC_pod (1-sec), EDP V leo COSMIC s/c High-gain occultation antennas for atmospheric profiling (50 Hz)

Total electron content data (podTEC) COSMIC generates TEC arcs per day Sampling rate is 1 -sec

Absolute TEC processing Correct Pseudorange for local multipath Fix cycle slips and outliers in carrier phase data Phase-to-pseudorange leveling Differential code bias correction

P1 MultipathP2 Multipath Satellite Multipath and Solar Panel Orientation

Pseudorange multipath calibration

Phase-to pseudorange leveling statistics

COSMIC DCBs for ~ 1 year Quality of absolute TEC from COSMIC ~2 TECU

Comparison of Calibrated Slant TEC Measurements for June 26, 2006 An example of comparison of calibrated TEC between JPL and UCAR There appears to be a 2-3 TECU bias between JPL and UCAR slant TEC Negative TEC, differences between UCAR and JPL elevation cutoff angles Similar data volumes between JPL and UCAR Good match Calib. Different Elev cutoff angle differences? Negative TEC From presentation by Brian Wilson, JPL

Observed TEC Rays in 12-hour period

… observed in Local time

Latency of COSMIC podTec data

Profile retrieval method  TEC = solid - dashed[Schreiner et al., 1999] Inverted via onion-peeling approach to obtain electron density N(r) Assumption of spherical symmetry

First collocated ionospheric profiles From presentation by Stig Syndergaard, UCAR/COSMIC

Comparisons with ISR data [Lei et al., submitted to JGR 2007]

Comparison of Ne(h) between COSMIC (red), Ionosondes (green)and TIEGCM (black) on Aug nd COSMIC agree well with ionosonde obs, especially the HmF2; Vertical structures from COSMIC coincide well with TIEGCM in the mid- lat, but not in the tropics. TIEGCM shows a bit higher HmF2 compared with obs.

Quiet Storm COSMIC #2 GAIM Comparisons during quiet and disturbed Conditions From presentation by Ludger Scherliess, Utah State University

Comparison of NmF2 and HmF2 between COSMIC and GAIM during Apr , 2006 Good agreement of NmF2 between COSMIC and GAIM; Higher peak heights from GAIM than those from COSMIC From presentation by Zhen Zeng, NCAR/HAO

Using GAIM to correct for gradients From presentation by Stig Syndergaard, UCAR/COSMIC Courtesy of Zhen Zeng

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?

RED = COSMIC sat BLUE = GPS sat Formosat-3/COSMIC Observations of Scintillations From presentation by Chin S. Lin, AFRL

Observed TEC Rays in 12-hour period

TIP nm passes 14 Sep 2006 FM1 FM3 FM UT (2100 LT) From presentation by Clayton Coker, NRL

Chung-Li COSMIC TBB/CERTO TEC and Elevation Angle From presentation by Paul A. Bernhardt, NRL

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 Data available to weather centers within < 180 minutes of on-orbit collection JCSDA NRL Neutral Atmosphere Operational Processing Science & Archive TACC

Summary COSMIC generates large amount of high quality space weather data Data available for real-time (significant amount of data with less than 60 min latency) and for post-processing Data are used for model comparison /improvement Global scintillation data will be available within months

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

Ionospheric profiles availability

Total Electron Content availability

Comparisons with ground-based data From presentation by Stig Syndergaard, UCAR/COSMIC Courtesy of Jiuhou Lei

First Formosat3 / COSMIC Workshop Space Weather Presentations 4-D Modeling of Ionospheric Electron Density with GNSS Data and the International Reference Ionosphere (IRI), D. Bilitza, M. Schmidt and C. Shum C.K. Shum - Ohio State University Occultation Measurements of the E-Region Ionosphere Paul Strauss - The Aerospace Corporation Ionospheric electron density specification using the FORMOSAT-3/COSMIC data Lung-Chih Tsai - Center for Space and Remote Sensing Research, NCU Validation of COSMIC ionospheric data Jiuhou Lei - NCAR/HAO Processing of FORMOSAT-3/COSMIC Ionospheric Data at CDAAC Stig Syndergaard - UCAR/COSMIC First Observations of the Ionosphere using the Tiny Ionospheric Photometer Clayton Coker - Naval Research Laboratory First NRL Results for the TBB/CERTO Radio Beacon Measurements Paul Bernhardt - Naval Research Laboratory Does FS3/COSMIC Data Improve Ionospheric Specification? Craig Baker - AFRL Global 3D Imaging of the August Storm using COSMIC Data Gary Bust - Atmospheric & Space Technology Research Associates

First Formosat3 / COSMIC Workshop Space Weather Presentations (contd.) Characteristic Analysis of COSMIC Ionospheric Electron Density Profile: Preliminary Results Yen-Hsyang Chu Observations of Global Ionospheric Sructure by FORMOSAT-3/COSMIC Charles Lin - National Space Organization (NSPO) Ionospheric F2-layer Parameter Mapping Based on the FORMOSAT-3/COSMIC Data Lung-Chih Tsai - National Central Univ, Taiwan, ROC Comparisons of Formosat-3/COSMIC ionospheric data with ground based measurements and model simulations Zhen Zeng - UCAR/COSMIC On the use of COSMIC podTEC data in the Electron Density Assimilative Model (EDAM) Matthew Angling - QinetiQ, UK Assimilating Formosat-3/COSMIC Ionospheric Data Into A Global Model: Preliminary GAIM Results Brian Wilson - JPL Assimilation of COSMIC Data with the USU GAIM Model Ludger Scherliess - Utah State University Preliminary results from COSMIC Campaigns Santimay Basu - Air Force Research Laboratory Calibration of COSMIC Ionospheric Occultation Profiles using the Arecibo Incoherent Scatter Radar Michael Kelley - Cornell University Formosat-3 COSMIC Campaign Observations at Kwajalein Atoll Chin Lin - Air Force Research Laboratory

A compilation of selected slides presented at the First FORMOSAT-3/COSMIC Data Users Workshop Boulder, CO, October 16-18, 2006 & COSMIC Retreat, October 26-27, 2006

COSMIC NmF2 - 1 week

TIP observations over large area on 14 Sep 2006 FM6 pass 1042UTFM6 pass 0907UTFM6 pass 0730UT FM3 pass 1050UT FM3 pass 0914UTFM3 pass 0738UT FM4-PINH pass 1050UT FM4-PINH pass 0914UTFM4-PINH pass 0738UT FM1 pass 1140UTFM1 pass 1005UTFM1 pass 0828UT From presentation by Santimay Basu, AFRL

COSMIC agree well with ionosonde observations; Global map of NmF2 revealed from COSMIC is well represented by TIEGCM model, though TIEGCM shows higher peak density in the low latitude. Maps of NmF2 for COSMIC (dots), Ionosondes (stars), TIEGCM (contour)

COSMIC agree well with ionosonde observations; Global map of NmF2 revealed from COSMIC is well represented by TIEGCM model, though TIEGCM shows higher peak density in the low latitude. Maps of NmF2 for: COSMIC (dots), Ionosondes (stars), TIEGCM (contour) From presentation by Zhen Zeng, NCAR/HAO

NmF2 (left) and HmF2 (right) Comparison between TIEGCM and COSMIC on Aug. 2nd Compared with COSMIC, TIEGCM show smaller peak density in the summer hemisphere, but larger one in the winter hemisphere; TIEGCM have lower HmF2 in the polar region.

Sample Comparison Between Arecibo, UCAR, and JPL Profiles: Best Agreement From presentation by Mike Kelley, Cornell University

COSMIC Occultation Over South Atlantic: 1815 UTC Black: Cosmic Blue: IRI Red: IDA3D Horizontal Lines Representation Error From presentation by Gary S. Bust, Atmospheric & Space Technology Research Associates

Precision of GPS RO soundings PPUTLS = Precision Parameter of Upper Troposphere and Lower Stratosphere, which is the mean absolute differences in the km layer 0.02% difference in refractivity, which is equivalent of 0.05 C in temperature

Two COSMIC Occultations taking place right next to each other, passing through nearly the same portion of the atmosphere.

Deviation of pairs of RO soundings separated by less than 10 km

CHAMP vs. ionosondes (NmF2) August 2002August 2005