15 Use of TIR from Space in Operational Systems
259
include tides, to global eddy-resolving systems that provide estimates of the ocean
state, updated regularly (from daily to monthly), providing forecasts from a few
days to 1 month ahead (Dombrowsky et al., 2009).
15.5.1 Use of TIR Products
SST strongly co-varies with the ocean temperature over the mixed layer depth
(50–100 m) and complements altimetry data in multi-variate ocean analyses
(Brassington, 2009). Short-range ocean forecasting systems such as the UK
Met Office Forecasting Ocean Assimilator Model (FOAM) (Martin et al., 2009)
and BLUElink Ocean Model, Analysis and Prediction System (OceanMAPS:
Brassington et al., 2007) assimilate level 2 SST data. The FOAM model is run daily
in the operational suite at the UK Met Office at global 1/4 ◦ resolution with nested
1/12 ◦ resolution regional configurations. The OceanMAPS model is run twiceweekly at the Australian Bureau of Meteorology at global 0.1–2 ◦ horizontal resolution with nested 0.1 ◦ resolution over the Australian region (Brassington et al., 2007).
For satellite SST, FOAM uses only GHRSST-L2P files in its data assimilation.
FOAM assimilates infrared SST data obtained from AATSR and AVHRR (from
NOAA and MetOp-A satellites) in addition to microwave SSTsubskin data from
AMSR-E. The satellite observations are combined into one observation (“superobbed”) by calculating the median of all observations of a particular type within
a 13 km radius. The model counterparts of these observations are calculated during a 1-day model run in a first-guess-at-appropriate-time scheme (Martin et al.,
2009). The observations undergo a bias correction using AATSR and in-situ data
as reference data. The bias-corrected observations and their model counterparts are
then used in an optimal interpolation type scheme to produce 2 dimensional SST
increments (Martin et al., 2009).
OceanMAPS uses the BLUElink Ocean Data Assimilation System (BODAS –
Oke et al., 2008) as its (re-)analysis component. The operational BODAS system
assimilates AMSR-E SSTsubskin retrievals from the Aqua satellite and IR SST from
AVHRR. It has been demonstrated that the addition of infrared GAC AVHRR L2P
SSTdepth files from NAVOCEANO (Table 15.1) results in BODAS analyses closer
to buoy observations compared with assimilation of the AMSR-E and GAC AVHRR
SST data streams separately (Andreu-Burillo et al., 2010).
Other ocean modelling systems (such as TOPAZ, NMEFC, Mercator and
MOVE/MRI.COM) assimilate gap-free (level 4) SST analyses rather than level 2
products (Dombrowsky et al., 2009).
15.5.2 TIR Requirements
Ocean models require satellite SST for assimilation that is reliable, timely and
accurate. Spatial resolution of the IR SST assimilated into ocean models is not
259
include tides, to global eddy-resolving systems that provide estimates of the ocean
state, updated regularly (from daily to monthly), providing forecasts from a few
days to 1 month ahead (Dombrowsky et al., 2009).
15.5.1 Use of TIR Products
SST strongly co-varies with the ocean temperature over the mixed layer depth
(50–100 m) and complements altimetry data in multi-variate ocean analyses
(Brassington, 2009). Short-range ocean forecasting systems such as the UK
Met Office Forecasting Ocean Assimilator Model (FOAM) (Martin et al., 2009)
and BLUElink Ocean Model, Analysis and Prediction System (OceanMAPS:
Brassington et al., 2007) assimilate level 2 SST data. The FOAM model is run daily
in the operational suite at the UK Met Office at global 1/4 ◦ resolution with nested
1/12 ◦ resolution regional configurations. The OceanMAPS model is run twiceweekly at the Australian Bureau of Meteorology at global 0.1–2 ◦ horizontal resolution with nested 0.1 ◦ resolution over the Australian region (Brassington et al., 2007).
For satellite SST, FOAM uses only GHRSST-L2P files in its data assimilation.
FOAM assimilates infrared SST data obtained from AATSR and AVHRR (from
NOAA and MetOp-A satellites) in addition to microwave SSTsubskin data from
AMSR-E. The satellite observations are combined into one observation (“superobbed”) by calculating the median of all observations of a particular type within
a 13 km radius. The model counterparts of these observations are calculated during a 1-day model run in a first-guess-at-appropriate-time scheme (Martin et al.,
2009). The observations undergo a bias correction using AATSR and in-situ data
as reference data. The bias-corrected observations and their model counterparts are
then used in an optimal interpolation type scheme to produce 2 dimensional SST
increments (Martin et al., 2009).
OceanMAPS uses the BLUElink Ocean Data Assimilation System (BODAS –
Oke et al., 2008) as its (re-)analysis component. The operational BODAS system
assimilates AMSR-E SSTsubskin retrievals from the Aqua satellite and IR SST from
AVHRR. It has been demonstrated that the addition of infrared GAC AVHRR L2P
SSTdepth files from NAVOCEANO (Table 15.1) results in BODAS analyses closer
to buoy observations compared with assimilation of the AMSR-E and GAC AVHRR
SST data streams separately (Andreu-Burillo et al., 2010).
Other ocean modelling systems (such as TOPAZ, NMEFC, Mercator and
MOVE/MRI.COM) assimilate gap-free (level 4) SST analyses rather than level 2
products (Dombrowsky et al., 2009).
15.5.2 TIR Requirements
Ocean models require satellite SST for assimilation that is reliable, timely and
accurate. Spatial resolution of the IR SST assimilated into ocean models is not