Occultation TEC Measurements from FORMOSAT-3/COSMIC - IGS

Occultation TEC Measurements from
FORMOSAT-3/COSMIC
Tiger J.Y. Liu, GPSARC, NSPO, NOAA
Institute of Space Science, College of Earth Sciences,
National Central University, TAIWAN

Outline
FORMOSAT-3/COSMIC
Tropospheric Observation
Ionospheric Observation
Seismo-ionospheric Study
FOEMOSAT-7/COSMIC-2
Summary
2
21-Jul-10

Solar Terrestrial Environment

Thermosphere
Plasmasphere
(Protonsphere)
Ionosphere
Mesosphere
Stratosphere
Neutral Atmosphere
Troposphere

TECu
120
Ionospheric total electron content
(TEC) derived from GPS
Receiver: YMSM (North Taiwan)
L1:1575.42 MHz (10.23 MHz×154 )
L2:1227.60 MHz (10.23 MHz×120)
C/A code (1.023 MHz)
P code (10.23 MHz)
90
60
30
0
08:00 14:00 20:00 02:00 08:00
(x i , y i , z i ) Local Time
TEC (total electron content)
unit: TECu (10 16 ele/m 2 )
ionosphere
S o =[(x i -x j ) 2 +(y i -y j ) 2 +(z i -z j ) 2 ] 1/2
Line-of-sight
(x j ,y j , z j )
6

FORMOSAT-3/COSMIC
Space-based GPS receiver

FORMOSAT-3/COSMIC
Global Real-time
Weather (Meteorology)
Space Weather (Ionosphere)
Observation and Prediction
The FORMOSAT-3/COSMIC program is an international
collaboration between Taiwan and the United States that
will use a constellation of six remote sensing microsatellites
to collect atmospheric data for weather prediction and for
ionosphere, climate and gravity research. Data from the
satellites will be made freely available to the international scientific
community in near real-time.

FORMOSAT-3/COSMIC
• FORMOSAT-3/COSMIC
Constellation was launch at
01:40 UTC, April 14, 2006
(Taiwan Time: April 15 2006) at
Vandenberg Air Force Base,
CA. Minotaur Launch
• Maneuvered into six different
orbital planes (inclination ~72°)
for optimal global coverage (at
~800 km altitude).
• All satellites are in good
health and providing science
data.

FORMOSAT-3/COSMIC
The FORMOSAT-3/COSMIC system is a
constellation of 6 LEO micro-satellites
Each satellite carries 3 payloads:
– GPS occultation ti receiver
– Tiny Ionospheric
Photometer
– Tri-Band Beacon.
Global observation of pressure,
temperature, water vapor,
refractivity, ionospheric
electron density and
scintillation for weather and space weather
research as well as climate monitoring
Demonstrate quasi-operational GPS limb
sounding with global coverage in near-real
time

Global
Positioning
i
System

Gps Occultation eXperiment (GOX)

FORMOSAT-3/COSMIC
Profiling the Troposphere, Stratosphere and Ionosphere by Radio Occultation

Mission Orbit of FORMOSAT-3/COSMIC

FORMOSAT3/COSMIC
-Troposphere
p
Walker Circulation: La Niña, El Niño
Hadley Circulation: Plateau Heating
Polar Circulation: Planetary Wave

Distribution of occultation events observed
by FORMOSAT-3
More than 2500 radio occultation (RO) soundings (green dots)
obtained by the GPS Occultation Experiment (GOX) each day. In
comparison, radiosondes d (red dots) provide only approximately 1500
soundings per day.

Super Typhoon Jangmi (2008)

COSMIC Profile Availability
22.5-1.5 1.5-4.5 4.5-7.5 7.5-10.5
10.5-13.5 13.5-16.5 16.5-19.5 19.5-22.5
22.5-1.5(+1d)
00 00z 00z
DA time window
Free forecast
NCEP GFS for IC and LBC
Availale conventional data
COSMIC data is available continuously
Not like radiosonde data available only at 00 and 12Z
Not like radiosonde data available only at 00 and 12Z
Cycling 3DVAR for long data assimilation time window
is one of the optimal assimilation scheme

Cold 3DVAR vs Cycling 3DVAR
Cold 3DVAR
Cycling 3DVAR
Significant improvement for trackforecast in cycling
3DVAR

El Niño La Niña
Walker Circulation

La Niña
El Niño
[Webster and Chang, J. Atmos. Sci., 1988]

Global F3/C tropopause height
ENSO Warm
ENSO Cold
Normal
ENSO Warm

(b)
Tropospheric Pressure
ENSO Warm
ENSO Cold
Normal
ENSO Warm
21-Jul-10
23

Tropospheric Temperature
ENSO Warm
ENSO Cold
Normal
ENSO Warm

Tropospheric Water Vapor
ENSO Warm
ENSO Cold
Normal
ENSO Warm

Tibetan Plateau Heating
Hadley Circulation and
the reserved

Global Tropopause Height in July 2008

Global Tropopause Height in July 2009

Polar Cell Circulation
Planetary Wave

The planetary wave signature

FORMOSAT3/COSMIC
-Ionosphere

Distribution of occultation events
observed by FORMOSAT-3
GOX

Ionosphere
EIA and Plasma Cave
Plasma Depletion Bay
Pre-earthquake Anomaly

Equatorial plasma fountain
Altitude (km)
Low-Latitude Ionosphere is dominated by the
electrodynamics
1000
900
800
Plasma
fountain
magnetic
field line
700
600
500
400
300
200
1600 LT
Ratcliffe [1972]
LT 10:00
1000
800
600
400
200
−20 0 20 40
LT 13:00
1000
800
600
400
200
−20 0 20 40
LT 16:00
1000
100
−10 0 10 20 30 40
Geographic Latitude
A model simulated plasma fountain effect
starting ti in the morning and enhance to its
maximum around noon
800
600
400
200
−20 0 20 40

Altitde [km]
500
400
0100
300
200
100
Equatorial Ionization Anomaly
0700 1000 1500
[e]/cm 3 x 10 5
10
0300 0730 1030 1600 8
9
7
0500 0800 1100 1700
6
0530 0830 1200 1900
5
4
0600 0900 1300 2100 3
2
0630 0930 1400 2300
1
−45 −30 −15 0 15 30 45
Geomagnetic latitude [ o N]
Lin et al.[GRL 2008]
July-August 2006
0

2007 M-month

2007 J-month

2007 S-month

Ionospheric plasma cave/tunnel
(a)
(b)
Plasma cave
Plasma Tunnel
Liu et al. (JGR, 2010)

Plasma Depletion Bay

Plasma Depletion Bay observed by F3/C and TIMED GUVI
Nighttime ionospheric structures, 23:00 LT (global fixed local time)
1.5
1.0
0.5
0
Geo eographic Latitud ude ( ° N)
50
40
30
20
10
0
−10
−20
−30
−40
TIMED−GUVI 135.6nm PLOT YEAR=2006; DOY=141−153; TIME=20−22LT
−50
−180 −150 −120 −90 −60 −30 0 30 60 90 120 150 180
Geographic Longitude ( ° E)
Rayleights
8
6
4
2
0

Plasma depletion bay
Nighttime ionospheric structures: 3‐D images

Mid-latitude trough

Result and Interpretation
FORMOSAT/COSMIC NmF2, M-month, 20:00MLT
Pole edge
EIA peak
Pole edge
Trough
Trough
Equator edge

FORMOSAT-3/COSMIC NmF2 Persudo-3D structure
Northern Hemisphere, M-month
lat ×alt ×time: 2°×2km ×0.5hr
21-Jul-10
49

Seasonal Variation
Northern hemisphere
Southern hemisphere
50
21-Jul-10

21-Jul-10
51

21-Jul-10
52

Seismo-ionospheric Precursor of
the 12 May 2008 M7.9 Wenchuan
Earthquake

China Earthquakes
1998/05/01~2008/05/12 36 M 6.0 earthquakes
2008/5/12 M7.9 Wenchuan Earthquake

Locations of the 35M6.0 earthquakes together with Wenchuan earthquake
occurred in China during May 1, 1998-May 12, 2008.

A time series of GPS TEC right above the epicenter of the M7.9
Wenchuan earthquake on May 15, 2008.

The GIMs observed at 08:00UT and global fixed 15:00 LT on day 6 before
the 2008 Mw7.9 Sichuan Earthquake.
0800UT
1500LT
R =10 043M 0.43M

D-6, 5/6 2008
0600UT, 1300LT
D-5, 5/7 2008
0600UT, 1300LT
D-4, 5/8 2008
0600UT, 1300LT
D-3, 5/9 2008
1400UT, 2100LT
D 2 5/10 2008
D-2, 5/10 2008
0400UT, 1100LT

Liu et al.[JGR, 2009]

Conclusion
F3/C constantly observes the temperature,
pressure, water vapor in the troposphere,
which is essential for weather forecast and
climate study.
F3/C probes 3-D structures and dynamics of
the ionospheric electron density and can be
applied on space weather monitoring.
F3/C+GIM should be useful to explore
seismo-ionospheric anomalies of the GPS
TEC before large earthquakes.

Ground- and Space-Based
GPS Observations
IRI assimilation
GIM + F3/C TEC

GIM TEC vs. GIM+F3/C TEC
Latitude (°N)
Longitude (°E)

FORMOSAT-7/COSMIC-2
12 satellites
Tri-G
2014, 2017

FORMOSAT/COSMIC-Follow On
Builds on the weather forecasting and
ionospheric science success of
FORMOSAT-3/COSMIC
Taiwan/NSPO and US/NOAA
12 satellites + TriG receiver
First launch 2014, second launch ~2017
Improved performance
5x+ increase in number of measurements
Higher precision in the atmosphere/ionosphere
C/NOFS Science Workshop 68
May 20, 2010

FORMOSAT-7/COSMIC-2 v.s. . FORMOSAT-3/COSMIC
Mission
Spacecraft
FORMOSAT-7/COSMIC-2
Establish an operational
mission for near real-time
numerical weather prediction
8,000 (threshold) profiles per
day (the objective number is
10,000)
NSPO design, procure, and
integrate t 12 SCs
NSPO will integrate new GNSS
PL provided by JPL and perform
12 SCs Integration and Test at
NSPO
FORMOSAT-3/COSMIC
Demonstration of near real-time
numerical weather prediction
1,600~1,800 profiles per day
NSPO define system
requirement
NSPO and Orbital design SC ;
UCAR provide PL suite
EDU and FM1 I&T at Orbital
FM2 to FM6 integration and test
at NSPO
Mission GPS/GALILEO/GLONASS GPS tracking capability
Payload tracking capabilities

FORMOSAT-7/COSMIC-2 v.s. . FORMOSAT-3/COSMIC
Launch
Vehicle
Ground
Operations
Data
Processing
FORMOSAT-7/COSMIC-2
NOAA will provide 2 (TBR)
launches into selected
orbits/inclinations
NOAA’s responsibility to seek
the ground Networks
High degree of automated
ground system for 12-satellite
constellation
Taiwan Data Processing
Center
US Data Processing Center
FORMOSAT-3/COSMIC Mission
Use MINOTAUR LV of the US Air
Force via UCAR’s help
Use USN ground stations for the
first 2 years, and then supported
by NOAA ground stations after 2
years
6-satellite constellation operations
TACC and CDAAC

Social Impacts
Explore Space
Weather Sciences
Enhance the Capabilities of
Regional and Global
Weather Prediction
Monitor Climate Trend
Enhance the Capability
Enhance the Capability
on Severe Weather
Prediction

Mission Architecture
GALILEO
GLONASS-CDMA
High-Inc
GPS
FORMOSAT-7/
COSMIC-2
Low-Inc
TT&C stations
(Taiwan)
Remote TT&C stations
(overseas)
Fiducial
Network
Data Processing Center
Satellite Operations
and Control Center Users Researchers

Potential Constellation
72° (6) and 35° (6)

Summary
F3/C (future F7/C2) provides the global
ionospheric i electron density in real time
which should be helpful to contracture a
ground/space-based GIM of the GPS TEC.
F3/C (future F7/C2) should also be useful
for the tropospheric climatology study.
21-Jul-10
74

Thank you!!!
太 空 所 ISS