Transcript Gosud-Samos_jgunn_final

Aquarius Sea Surface Salinity
satellite mission validation
using near real-time, in-situ oceanographic data
John T. Gunn, AVDS Manager
Earth & Space Research
1910 Fairview Ave. E., Suite 210
Seattle, WA 98102
Ph: 206-726-0501; Email: [email protected]
1st Joint GOSUD/SAMOS Workshop
Boulder, Colorado
2-4 May, 2006
Salinity Satellite Mission
International Partnership Mission
• Aquarius Salinity Microwave
Instrument
• Service Platform and SAC-D
Science Instruments
• Launch Vehicle
• Mission Operations & Ground
System
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Salinity Satellite Mission
Single Day Orbit Swath Pattern
The orbit precesses to yield complete coverage in 7 days
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Mission Design and Sampling Strategy
Salinity Satellite Mission
Sun-synchronous exact repeat orbit
6pm ascending node
Altitude 657 km
• Global Coverage in 7 Days
• 4 Repeat Cycles per Month
Beams point toward
the night side to avoid sun glint
In
Orbit
Check
out
Surface Validation
3 beams
390 km wide swath.
76 x 94 km
96 x 156 km
Aquarius
Ground System
84 x 120 km
Launch
March 2009
Salinity Data
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The Aquarius Validation Data Segment (AVDS) will collect
and process surface measurements for the Aquarius data
processing
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Liaison with observers
Daily data acquisition
Quality control/editing
Uniform data format
AVDS
Deliver surface
calibration data to
Aquarius and SMOS
Data Processing
Centers
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AVDS In-situ Data Sources
Salinity Satellite Mission
Validation Data Sampling Parameters
Platform
Quantity
Type
Distribution
Min Depth
Latency
Argo Buoys
~300/day
Profile float
Ocean-wide
5m
1 day
TAO/Triton1
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With salinity
Mooring
Tropical Pac
1m
1 day
PIRATA
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Mooring
Tropical Atl
1m
1 day
GDP buoys2
Sfc Salinity
50 to 300
Surface drifter
Ocean-wide
0.5 m
2 mos
Shipboard
Thermosalinograph
varies
Hull-mounted
Ocean-wide
5m
2 days
GTSPP
varies
CTD profile
Ocean-wide
1m
TBD
1Funding
2Funding
for additional sensors and 50 additional buoys planned for FY07
for 50 buoys with near surface S sensors in FY07 ramping up to 300 in FY09
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Salinity Satellite Mission
In-situ data
GTSPP
Via ftp
daily
AVDS
ADPS
ESR
GSFC
USERS
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AVDS-ADPS Interaction
AVDS provides:
-Position (latitude, longitude)
-Time
-Acceptable deltas for position and time
-Format is ASCII
-Other identifying information (TBD)
ADPS returns:
All Aquarius data collected within position and time windows
-Format is ASCII
-Include brightness Temp (TB), derived salinity, position, time
of Level 2 data (along track)
-Other identifying information (TBD)
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User Community Products
Salinity Satellite Mission
AVDS will provide the following to the surface salinity user community:
•Tabular collection of in-situ and Aquarius SSS data for matched pairs
•Description of statistical selection process by in-situ data type
•Access to match-up criteria, in-situ data and edited, tabular coincident
measurements via data servers, as shown below.
AVDS
In-situ
data base
Position, time
Window for
matchup
Edited,
tabulated
Coincident
meas.
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• Exchange formats between AVDS and ADPS will use an established
system developed for the SeaWifs system
• The existing format structure will require only slight modifications to
adapt to the Aquarius validation requirements
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Surface Current Data validation
ESR Satellite derived surface currents with validation using GDP buoys
www.oscar.noaa.gov
www.esr.org
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Desired Validation Database Attributes
Searchable in time and space
Reasonable level of Quality Control
Format with comfortable ease-of-use
Source Traceability and documentation (metadata)
Internet access to data in near real-time (< 1 week delay)
Two examples follow; GOSUD thermosalinograph underway data and
ARGO profiling buoys data
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GOSUD Data Distribution 2006
Data is stored by year and ship
2006 data as of end of April 2006
Distribution somewhat constant in time (~5-6K point per week)
Some outliers in position
Cruise tracks repeated (limited mid-Pacific coverage)
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ARGO Data Distribution
Data is stored in daily files
Two consecutive days in April
Number of data points drops but distribution in time is similar
Duplicate points exist for April 24th data (can affect statistics)
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Conclusions
• Access and ease of use for global data bases are significantly
improved over the last few years
• Aquarius will require access to validation in near real-time mode. As
such, initial QC is very important
• Idiosyncrasies of various validation data sets will require careful
evaluation in their application to satellite fields
• Delayed mode data (high QC level) will be important for re-analysis
efforts but are probably delayed too long for use in validating initial
data distribution
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