www.ncof.gov.uk
OSTIA : Transition to an Operational System
John Stark, Craig Donlon.GlobColour / Medspiration Workshop, 4-6 Dec. 2006
www.ncof.gov.uk
Overview
OSTIA : Operational Sea surface Temperature and sea Ice Analysis
• Description of the OSTIA system.– Data processing– Analysis & bias correction.– Products.
• From innovation to operation. – The transition process.– Operational status.
• Products and verification.
www.ncof.gov.uk
Operational SST & Sea Ice Analysis
• Daily 1/20° (~5.6km) global SST analysis using optimal interpolation.
• Blend of data sources, using satellite (microwave & IR) and in situ data.
• Now running daily in an operational suite starting at 0600 UTC.
• Persistence based; No explicit model.
• Uses sea ice analysis performed by EUMETSAT OSI-SAF (met.no / DMI).
Sample analysis for 24 Jan 2006
www.ncof.gov.uk
Daily SST
Basic Architecture
Quality Control-Background check -Diurnal warming flagging
Satellite Bias Estimation-Find match-ups -O.I. estimate.
O.I. Analysis-Using 2 background error scales-Spatially varying backgrd. errors
Data Sources
Anomaly Persistence Forecast
With relaxation to climatology
www.ncof.gov.uk
OSTIA : Source DataSensor (Platform)
Type Resolution Data Source Coverage Subsa-mpling
AMSR-E(Aqua)
Microwave ~25km(swath)
Remote Sensing Systems (ssmi.com). L2P Format.
Global(~1 million/day)
22
TMI (TRMM) Microwave ~25km(swath)
Remote Sensing Systems (ssmi.com). L2P Format.
Tropics(~0.5 million/day)
None
AATSR (EnviSAT)
Infra-red ~1km (swath) Medspiration RDAC, L2P Format
Global(~2 million/day)
33
AVHRR -LAC(NOAA 17 & 18)
Infra-red ~1/10°(Grid)
Medspiration RDAC, L2P Format (NAR) &NAVOCEANO-JPL
North Atlantic (grid)(~0.5 million/day)
33
AVHRR -GAC(NOAA 17 & 18)
Infra-red ~1km(Swath)
NAVOCEANO-JPL (~2 million/day) None
SEVIRI (MSG1) Infra-red 0.1° (Gridded) Medspiration RDAC, L2P Format
Atlantic sector(~2 million/day)
None
In-Situ Ships, drifting and moored buoys.
In-situ Met Office MetDB (GTS)
Global(~25,000 /day)
None
Sea Ice SSMI, Gridded 10km, Gridded.
OSI-SAF (Met.no) Global. None.
www.ncof.gov.uk
Bias correction : The Importance of AATSR
AMSR-E Observations for 14 Dec. ‘05
Reference observations (With AATSR) Reference observations (No AATSR)
www.ncof.gov.uk
Bias correction : The Importance of AATSR
Match ups (<25km)More match ups especially in data-sparse areas
Analysed AMSRE bias for 14 Dec.
Large impact from additional match ups
www.ncof.gov.uk
AATSR bias correction & SSES.
• AATSR bias specification has a significant impact on OSTIA. • A short reanalysis showed that the AATSR SSES bias was
too large. • We appreciate the rapid response of Medspiration in
changing the SSES bias (from 0.33 to 0.19).– But the change was not directly communicated to us…
Difference (K) between operational OSTIA and a run with AATSR bias=0.0
www.ncof.gov.uk
Products
• Browsable SSTs and Anomalies
http://ghrsst-pp.metoffice.com/data/private/sst_monitor/ http://lovejoy.nerc-essc.ac.uk:8080/ncWMS/godiva2.html
www.ncof.gov.uk
Products, Users and Applications
• Seasonal forecasting.– E.g. Winter forecast.
• Climate monitoring, inc. ENSO.• Aviation Forecasting Centre• Research
– E.g. High resolution SSTs for monsoon modelling (U. Reading)
• Intercomparison / validation– NASA Short-term Prediction Research and
Transition Centre (SPoRT)• Data supplied in GHRSST L4 format via
website :– http://ghrsst-pp.metoffice.com/pages/latest_an
alysis/ostia.html
– ftp details available on request.• NWP boundary condition.
– Beginning extensive trials with NWP suite.• Will participate in GHRSST GEO Action : DA-
06-03 to use ensemble techniques to improve SST uncertainty estimation.
NASA Sport Web Page.
www.ncof.gov.uk
Maintenance 1015 - 1215Z
Maintenance 1715 - 1815Z
opmarine opepsopnoncritopssfmmsopssfmoptempopmesop00:00
01:00
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QN00 0030 - 0050Z
QV00 0140 - 0210Z
QW000350 - 0425Z
QD00 0230 - 0305Z
QO000500 - 0600Z
QQ000615 - 0710Z
QL00 0735 - 0750Z
QE000930 - 0950Z
QD06 0830 - 0905Z
QW121550 - 1625Z
QD12 1430 - 1505Z
QD18 2030 - 2105Z
QU180030 -0115Z
QG000240 - 0350Z
QY000125 - 0230Z(from QG18)
QU000630 -0715Z
QG060840 - 0925Z
QY060725 - 0830Z(from QG00)
QU061225 -1315Z
QG121440 - 1550Z
QY121325 - 1430Z(from QG06)
QU121830 -1955Z
QG182040 - 2125Z
QY181925 - 2030Z(from QG12)
QA000310 - 0400Z(from QG18)
Q400 0240 - 0300Z
Q4030420 - 0520Z(from QY00)
Q406 0840- 0900Z
Q4090915 - 1015Z(from QY06)
QA06 1235 - 1310Z(from QG18)
QA121515 - 1605Z(from QG06)
Q412 1440 - 1500Z
Q4151615 - 1715Z(from QY12)
QA18 2110 - 2130Z(from QG06)
Q418 2040 - 2100Z
QJ18 2305 - 2350Z(from QG12)
Q4212150 - 2255Z(from QY18)
QM21 0120 - 0135Z(from QG18)
QM00 0215 - 0245Z(from QG18)
QC00 0650 - 0700Z(from QG18)
QM03 0720 - 0735Z(from QG00)
QM06 0815 - 0845Z(from QG00)
QC06 1225 - 1245Z(from QG18)
QM09 1320 - 1335Z(from QG06)
QM12 1415 - 1445Z(from QG06)
QC12 1905 - 1915Z(from QG06)
QM15 1930 - 1945Z(from QG12)
QM18 2015 - 2045Z(from QG12)
QC18 2305 - 2320Z(from QG06)
QH090010Z - 0030Z
QH120110 - 0310Z
QH180710 - 0850Z
QH210910 - 0930Z
QH001310 - 1540Z
QH031610 - 1700Z
QH061910 - 2120Z
EG000350 - 0650Z(from QG00)
EG121550 - 1850Z(from QG12)
EY060825 -1305Z(from EG00 &
QY06)
EY182025 -0105Z(from EG21 &
QY18)
Prelim Global SSFM0325 - 0330Z
Global SSFM0410 - 0430Z
NAE SSFM0240 - 0310Z
Middle East SSFM0345 - 0350Z
Falklands SSFM1235 - 1245Z
NAE SSFM1440 - 1510Z
Middle East SSFM1550 - 1555Z
Global SSFM1610 - 1630Z
Prelim Global SSFM2125 - 2130Z
NAE SSFM2040 - 2110Z
Falklands SSFM2310 - 2320Z
Prelim Global SSFM0925 - 0930Z
NAE SSFM0840 - 0910Z
Prelim Global SSFM1525 - 1530Z
HALL1 (sx8) OPERATIONAL NWP SUITE SCHEDULE - 12 October 2006
Scott Irvine, 12 Oct 2006
Legend:Q4: UK 4km;T+3 & T+36QA: Southern AsiaT+9 & T+48QJ: AfricaT+48
Legend:QM: UK MesoscaleT+4 & T+48QC: FalklandsCAMMT+9 & T+48Q6: OSTIA SST
Legend:QH: Non Critical
Legend:QU: Global Update;T+9QG: GlobalT+48 & T+144QY: North Atlantic &EuropeanT+48
Legend:QD: NAE MarineSuiteQW: Global MarineSuiteQN & QV: FOAMQQ, QL & QE: Shelf-Seas Suite
QH150410 - 0430Z
fpss fpssfpfc fpfcfpfcfpfc fpfc
OPC
Fallback 0230
Fallback 0220
Fallback 0915
Fallback 0820
Fallback 2020
Fallback 2130
Fallback 1420
Fallback 1530
Fallback 0330
Fallback 0830
Fallback 1430
Fallback 2030
Legend:EG: GlobalEnsembleQY: NAEEnsemble
QZ180030 -0115Z
QZ000630 -0715Z
QZ061225 -1315Z
QZ121820 -1915Z
QJ06 1315 - 1335Z(recon from QG06)
QJ12 1820 - 1840Z(from QG12)
EY182025 -0105Z(from EG21 &
QY18)
Innovation to Operation…
• The transition to an operational system has many advantages
– Operators monitor the system 7 days a week.• Robust system.
– Machine resources are dedicated to the system (06000640 UTC).
– All procedures are clearly defined.– Allows rapid response to incidents.– Forces ‘Good Practise’, such as version control etc.
• But places requirements on the whole system:– All changes must be justified and documented.
• Any changes to data supply should be made a long time in advance if possible.
• Need stability in data delivery.– Not all operators have in-depth knowledge of the
system.• There should be simple ‘how-to’ procedures for likely
failure modes.– Processing MUST finish within the allocated time
period.
www.ncof.gov.uk
Sea Ice Reanalysis
• Currently performing a sea ice reanalysis for the SSMI era (1987-2005)– Hope to extend to SMMR (1979-1987).– Using processing system developed for the EUMETSAT
OSI-SAF.– Aim to quantify errors to provide a climate-quality
product.
Near 90 GHzNear 90 GHz
BootstrapBootstrap
NASA/TeamNASA/Team
Courtesy of Søren AndersenCourtesy of Søren Andersen
www.ncof.gov.uk
SST Reanalysis Plans
• SST Reanalysis back to 1981 using available satellite data and in situ obs.– Aim to produce a homogenous 25+ year SST data set for
seasonal forecasting by end of 2008. – Initially focus on Pathfinder (AVHRR) and (A)ATSR, by
end of 2007. – Intercomparison with other GHRSST (re-)analyses.– Requires access to (A)ATSR data for effective bias
correction.• Ideally L2P format.
– Open to collaboration• Error covariances, ensemble techniques, D.V. (ocean colour?),
aerosols (ocean colour)…
www.ncof.gov.uk
Priorities / Requests.
• Please maintain a continuous L2P data stream– Currently plan OSTIA to be the primary GMES Marine Core Services
L4 SST output. (Operational backup from France).– Recommend the L2P format as it facilitates the transition to new data
sources e.g. MetOp.
• Maintain AATSR Sentinel III– The presence of a high quality satellite SST data source is crucial to
our bias correction strategy.– Bias correction scheme will be compromised without AATSR.
• Ensure (A)ATSR is available (in L2P) for reanalysis efforts.• Please communicate changes to the system to users in an
operational manner (timely and accurate).
www.ncof.gov.uk
Conclusions
• We are treating Medspiration as an operational service– Using the service on a daily basis. – Have been some hiccups that should be ironed out .
• Short interruptions to the service have occurred.
• OSTIA’s strength is that is uses many complementary data sources.– Not totally reliant on a single data source – but accuracy
significantly enhanced by AATSR.
• Sea ice reanalysis will be available for use.