the cdr from sst cci · sst cci phase-ii esa climate change initiative phase-ii sea surface...
TRANSCRIPT
![Page 1: The CDR from SST CCI · SST CCI Phase-II ESA Climate Change Initiative Phase-II Sea Surface Temperature (SST) The CDR from SST CCI Chris Merchant ... trust in the quality • 1981](https://reader035.vdocument.in/reader035/viewer/2022071117/60077fca7e7b636832358f2e/html5/thumbnails/1.jpg)
SST CCI Phase-II
ESA Climate Change Initiative Phase-II
Sea Surface Temperature (SST)
www.esa-sst-cci.org
The CDR from SST CCI Chris Merchant University of Reading
![Page 2: The CDR from SST CCI · SST CCI Phase-II ESA Climate Change Initiative Phase-II Sea Surface Temperature (SST) The CDR from SST CCI Chris Merchant ... trust in the quality • 1981](https://reader035.vdocument.in/reader035/viewer/2022071117/60077fca7e7b636832358f2e/html5/thumbnails/2.jpg)
SST CCI Phase-II
R&D Passive Microwave Sensors
35 year uncertainty-quantified SST CDR Integrated, consistent L2, L3 & L4
![Page 3: The CDR from SST CCI · SST CCI Phase-II ESA Climate Change Initiative Phase-II Sea Surface Temperature (SST) The CDR from SST CCI Chris Merchant ... trust in the quality • 1981](https://reader035.vdocument.in/reader035/viewer/2022071117/60077fca7e7b636832358f2e/html5/thumbnails/3.jpg)
SST CCI Phase-II
New EO science in SST CCI Phase 2 § Known techniques cannot deliver SST CDR
requirements § New EO science required to
• Harmonise and stabilise AVHRRs/ATSR1 pre-1996 – Mutual bias correction across constellation – Instrument calibration modelling (essential work at L1b)
• Link AATSR to SLSTR via AVHRR-A/IASI • Achieve IR SST targets for noise and bias
– Smooth-atmosphere retrieval to reduce noise – Retrieval and cloud detection in presence of stratospheric aerosol
§ Fundamental work on new MW subskin-SST • in context of IR-dominated CDR
![Page 4: The CDR from SST CCI · SST CCI Phase-II ESA Climate Change Initiative Phase-II Sea Surface Temperature (SST) The CDR from SST CCI Chris Merchant ... trust in the quality • 1981](https://reader035.vdocument.in/reader035/viewer/2022071117/60077fca7e7b636832358f2e/html5/thumbnails/4.jpg)
SST CCI Phase-II
Passive Microwave SST § Can PMW SST be used to
enhance the SST CDR? • Enhanced frequency of
observation (at lower resolution) in cloudy areas
• Could damage observational stability of CDR relative to IR-only
§ Optimal estimation for AMSR-2 SST developed
• Information content analysis completed, to prioritise channels
• Significant BT-related and wind-stress related biases
Page 4 21 September 2015 PM5 - Met Office
6.9V Brightness Temperature / K
Est
imat
ed O
bs –
Sim
Bia
s / K
![Page 5: The CDR from SST CCI · SST CCI Phase-II ESA Climate Change Initiative Phase-II Sea Surface Temperature (SST) The CDR from SST CCI Chris Merchant ... trust in the quality • 1981](https://reader035.vdocument.in/reader035/viewer/2022071117/60077fca7e7b636832358f2e/html5/thumbnails/5.jpg)
SST CCI Phase-II
Initial PMW SST validation results
21 July 2015 GHRSST XVI Page 5
JAXA RSS CCI Matching Good Buoys 305 161 305 161 305 161 Mean Error / K 0.03 -0.04 -0.14 Robust SD / K 0.40 0.38 0.38
SS
T AM
SR –
SS
T in
situ
/ K
NWP wind speed / m/s
Wind-stress dependence of emissivity around 7 GHz is not well understood
![Page 6: The CDR from SST CCI · SST CCI Phase-II ESA Climate Change Initiative Phase-II Sea Surface Temperature (SST) The CDR from SST CCI Chris Merchant ... trust in the quality • 1981](https://reader035.vdocument.in/reader035/viewer/2022071117/60077fca7e7b636832358f2e/html5/thumbnails/6.jpg)
SST CCI Phase-II
Less noisy IR SST § For climate record, priority is to
• minimise biases • maximise sensitivity to true SST
(minimise prior influence)
§ Users also like data that isn’t noisy
• but obvious low-noise retrieval increase bias and prior influence
§ Experimental reprocessing introduced “smooth-atmosphere” retrievals
• the SST fields are not merely smoothed, even if it looks like it
• bias and sensitivity are unchanged
Page 6 21 September 2015 PM5 - Met Office
Low bias, normal noise
Low bias, low noise
![Page 7: The CDR from SST CCI · SST CCI Phase-II ESA Climate Change Initiative Phase-II Sea Surface Temperature (SST) The CDR from SST CCI Chris Merchant ... trust in the quality • 1981](https://reader035.vdocument.in/reader035/viewer/2022071117/60077fca7e7b636832358f2e/html5/thumbnails/7.jpg)
SST CCI Phase-II
Stratospheric aerosol events
7
0 0.3 Infra-red optical depth, Pinatubo aerosol
Causes bias in IR SST Good solution exists for ATSR: “aerosol robust” retrieval coeffs
El Chichon (1982) Pinatubo (1991)
![Page 8: The CDR from SST CCI · SST CCI Phase-II ESA Climate Change Initiative Phase-II Sea Surface Temperature (SST) The CDR from SST CCI Chris Merchant ... trust in the quality • 1981](https://reader035.vdocument.in/reader035/viewer/2022071117/60077fca7e7b636832358f2e/html5/thumbnails/8.jpg)
SST CCI Phase-II
El Chichon and AVHRRs § Tougher to get a good solution for
AVHRRs • Single view => good knowledge
of spectral impact more crucial • Fundamentally not enough
information in 2 or 3 channels => prior IR AOD
§ Derived using HIRS data a prior IR AOD for El Chichon event
§ Will use this in extension to the optimal estimation scheme presently used
§ Crucial step in extending CDR back to 1981
Page 8 21 September 2015 PM5 - Met Office
![Page 9: The CDR from SST CCI · SST CCI Phase-II ESA Climate Change Initiative Phase-II Sea Surface Temperature (SST) The CDR from SST CCI Chris Merchant ... trust in the quality • 1981](https://reader035.vdocument.in/reader035/viewer/2022071117/60077fca7e7b636832358f2e/html5/thumbnails/9.jpg)
FromMerchantetal.,2013communitypaperandroadmap:h"p://www.geosci-instrum-method-data-syst.net/2/305/2013/gi-2-305-2013.html
H2020 project EUSTACE Aim: to understand, parameterise and exploit relationships between satellite (skin) and meteorological air temperature, for global historical analysis
• SST CCI data will be exploited for air temperature analysis
• Key benefit: uncertainty information
EUSTACEhasreceivedfundingfromtheEuropeanUnionHorizon2020Research
andInnovaJonprogramme,underGrantAgreementnumber640171
![Page 10: The CDR from SST CCI · SST CCI Phase-II ESA Climate Change Initiative Phase-II Sea Surface Temperature (SST) The CDR from SST CCI Chris Merchant ... trust in the quality • 1981](https://reader035.vdocument.in/reader035/viewer/2022071117/60077fca7e7b636832358f2e/html5/thumbnails/10.jpg)
HadISST2.2 switch to SST CCI • Key benefit of SST CCI: improved AVHRR products • HadISST1 paper ~3000 citations
HadISST.2.1.0.0 ERSSTv3b Kaplan COBE HadISST1
![Page 11: The CDR from SST CCI · SST CCI Phase-II ESA Climate Change Initiative Phase-II Sea Surface Temperature (SST) The CDR from SST CCI Chris Merchant ... trust in the quality • 1981](https://reader035.vdocument.in/reader035/viewer/2022071117/60077fca7e7b636832358f2e/html5/thumbnails/11.jpg)
SST CCI Phase-II
Conclusions
§ Building an integrated “operations-ready” system (presented on Day 1)
§ Many innovations to improve the scientific quality of the CDR in progress, and to deal with challenges of early sensors
§ Key to wider user adoption and application will be combination of • reputation -- trust in the quality • 1981 to recent • ongoing extension of CDR in time
Page 11 21 September 2015 PM5 - Met Office