sst for cfsrr diane stokes and richard w. reynolds
DESCRIPTION
SST for CFSRR Diane Stokes and Richard W. Reynolds. Brief overview of SST analyses used for Nov 1981-2006 Focus on Daily OI SST. SST for CFSRR. OIv2 1 Degree Weekly Analysis Optimum Interpolation Available: Nov 1981 – present OI 1/4 Degree Daily Analysis from NCDC Optimum Interpolation - PowerPoint PPT PresentationTRANSCRIPT
SST for CFSRR Diane Stokes
and Richard W. Reynolds
• Brief overview of SST analyses used for Nov 1981-2006
• Focus on Daily OI SST
SST for CFSRR
• OIv2 1 Degree Weekly Analysis– Optimum Interpolation– Available: Nov 1981 – present
• OI 1/4 Degree Daily Analysis from NCDC– Optimum Interpolation– Currently available from 1985 - 2006
• Nov 1981-Dec 1984: Need daily AVHRR SST retrievals. (Pathfinder project may be working on this)
OI SST AnalysesWeekly OI.v2
• Grid: 1o • Data: 7 days of satellite,
ship & buoy. Plus, SSTs simulated from 7-day median ice.
• Satellite data • Infrared AVHRR
– 7-Day large-scale satellite bias correction (Poisson)
• Spatial error correlation: ~ 700 km
Daily OI from NCDC • Grid: 0.25o • Data: 3 days satellite,
ship & buoy. Plus, SSTs simulated from 7-day median ice
• Satellite data• Infrared AVHRR
• Microwave AMSR
– 7-Day large-scale satellite bias correction (EOT’s)
• Spatial error correlation: ~ 100 km
Source: Reynolds presentation at NOAA ARC PI Meeting, Sep 2007, modified
Source: http://www.ncdc.noaa.gov/img/climate/research/sst/oi4.jpg
• Top: AVHRR Pathfinder Bottom: AMSR-E
• For AVHRR:• Absolute latitudes > 40° have
roughly only 5 days of data
• Number of days increases toward the tropics
• Drop offs due to cloud cover
•
• For AMSR:• Absolute latitudes > 40° have
more than 20 days of data
• Drop offs due to precipitation in ITCZ and SPCZ
Jan '03: Number of Days with Nighttime Obs
Source: Reynolds presentation at NOAA ARC PI Meeting, Sep 2007
Magnitude of Gradient:Gulf Stream
• Daily OI using AMSR-E for January - March 2003
• Gradients have a stationary part due to topography– Thus, limited
AVHRR data are useful
Source: Reynolds presentation at NOAA ARC PI Meeting, Sep 2007
Data Anomalies: 11 Jan 2003Differences lead to day-to-day noise in OI
• AVHRR day & night– Note data
scarcity– Pathfinder:
local time
• AMSR day & night– Note swath
width & precipitation
– Day night differences not always diurnal warming
Source: Reynolds presentation at NOAA ARC PI Meeting, Sep 2007
4 Days of Buoy SST Data 0Z 22 March 22 - 0Z 26 March 26, 2006
• Resolution– 1 minute
• Averaged to– 1 hour– 1 day
• Consider random sampling – AMSR could
approach 2 obs/day
– AVHRR would be lower especially in winter
Source: Reynolds presentation at NOAA ARC PI Meeting, Sep 2007
Average Daily Spectra for 3 Years
•Buoy spectra closer to daily OI spectra when 3-days of data are used– Note:
AVHRR-only lower than AMSR+AVHRR spectra
Source: Reynolds presentation at NOAA ARC PI Meeting, Sep 2007
SST gradient magnitudes
• Three-day averages centered on 1 Oct 2003
• AMSR&AVHRR Daily OI gradient most resembles AMSR data gradient
• AVHRR-only Daily OI does well despite poor data coverage.
Image Source: Reynolds, R. W., T. M. Smith, C.Liu, D. B. Chelton, K. S.
Casey and M. G. Schlax, 2007
SST gradient magnitudes3-day average
Image Source: Reynolds, R. W., T. M. Smith, C.Liu, D. B. Chelton, K. S. Casey and M. G. Schlax, 2007
As in previous slide, but for eastern Pacific cold tongue
Running in Real Time
In real time, a preliminary and final version of the Daily OI SST would be produced.
The final version would be delayed approximately two weeks to provide the wider data window for the satellite bias correction