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P.J. Minnett
is anticipated that these instruments will continue the SST time series into the next
decade, perhaps longer for VIIRS, and thus will require as extensive validation as
their heritage instruments if they are to contribute to the SST CDR.
14.7 Conclusions
While there have been significant improvements in the demonstrated accuracies
of SSTs derived from infrared radiometers on satellites in recent years, the most
stringent requirements have not yet been met. These improvements have resulted
from better atmospheric correction algorithms, and more accurate cloud and aerosol
screening. They have also benefited from improved validation methods including
the increasingly more widespread use of ship-bard radiometers. The usual approach
is to attribute all of the uncertainties derived from the validation exercise to the satellite retrieval, despite there being additional sources of error. Thus we are still in the
position of believing that the satellite SST retrievals are more accurate than demonstrated, but are not able to quantify with confidence the true accuracies. Innovative
analysis approaches (e.g. O’Carroll et al., 2008) indicate a possible way forwards,
and improved understanding of the physics controlling the skin layer and diurnal
heating will lead to better corrections for these effects (e.g. Donlon et al., 2002;
Gentemann et al., 2009a).
An important aspect of recent developments in this area is the increasing coordination between researchers in the field, and the GHRSST project (formerly the
GODAE High Resolution SST Pilot Project; now the Group for High Resolution
SST; Donlon et al., 2007) and the national components (e.g. Gentemann et al.,
2009b) have played a significant role in this. Also the establishment of a methodology to cooperatively refer radiometer calibration to a NIST radiometric standard
(Rice et al., 2004; Barton et al., 2004) has also laid the foundation of deriving a
Climate Data Record for SST.
Acknowledgements The support of NASA over many years is gratefully acknowledged as it
has facilitated much of the work that is included here. Discussions with many colleagues have
helped clarify the issues involved in the physics of the measurements and in the approaches to SST
validation.
References
Aguirre M, Berruti B, Bezy J-L, Drinkwater M, Heliere F, Ulf Klein, Mavrocordatos C, Silvestrin
P, Greco B, Benveniste J (2007) Sentinel-3. The ocean and medium-resolution land mission for
GMES operational services. ESA Bull 131:24–29
Barton IJ, Minnett PJ, Donlon CJ, Hook SJ, Jessup AT, Maillet KA, Nightingale TJ (2004)
The Miami2001 infrared radiometer calibration and inter-comparison: 2. Ship comparisons.
J Atmos Ocean Tech 21:268–283
Branch R, Jessup AT, Minnett PJ, Key EL (2008) Comparisons of shipboard infrared sea surface skin temperature measurements from the CIRIMS and the M-AERI. J Atmos Ocean Tech
25:589–606
P.J. Minnett
is anticipated that these instruments will continue the SST time series into the next
decade, perhaps longer for VIIRS, and thus will require as extensive validation as
their heritage instruments if they are to contribute to the SST CDR.
14.7 Conclusions
While there have been significant improvements in the demonstrated accuracies
of SSTs derived from infrared radiometers on satellites in recent years, the most
stringent requirements have not yet been met. These improvements have resulted
from better atmospheric correction algorithms, and more accurate cloud and aerosol
screening. They have also benefited from improved validation methods including
the increasingly more widespread use of ship-bard radiometers. The usual approach
is to attribute all of the uncertainties derived from the validation exercise to the satellite retrieval, despite there being additional sources of error. Thus we are still in the
position of believing that the satellite SST retrievals are more accurate than demonstrated, but are not able to quantify with confidence the true accuracies. Innovative
analysis approaches (e.g. O’Carroll et al., 2008) indicate a possible way forwards,
and improved understanding of the physics controlling the skin layer and diurnal
heating will lead to better corrections for these effects (e.g. Donlon et al., 2002;
Gentemann et al., 2009a).
An important aspect of recent developments in this area is the increasing coordination between researchers in the field, and the GHRSST project (formerly the
GODAE High Resolution SST Pilot Project; now the Group for High Resolution
SST; Donlon et al., 2007) and the national components (e.g. Gentemann et al.,
2009b) have played a significant role in this. Also the establishment of a methodology to cooperatively refer radiometer calibration to a NIST radiometric standard
(Rice et al., 2004; Barton et al., 2004) has also laid the foundation of deriving a
Climate Data Record for SST.
Acknowledgements The support of NASA over many years is gratefully acknowledged as it
has facilitated much of the work that is included here. Discussions with many colleagues have
helped clarify the issues involved in the physics of the measurements and in the approaches to SST
validation.
References
Aguirre M, Berruti B, Bezy J-L, Drinkwater M, Heliere F, Ulf Klein, Mavrocordatos C, Silvestrin
P, Greco B, Benveniste J (2007) Sentinel-3. The ocean and medium-resolution land mission for
GMES operational services. ESA Bull 131:24–29
Barton IJ, Minnett PJ, Donlon CJ, Hook SJ, Jessup AT, Maillet KA, Nightingale TJ (2004)
The Miami2001 infrared radiometer calibration and inter-comparison: 2. Ship comparisons.
J Atmos Ocean Tech 21:268–283
Branch R, Jessup AT, Minnett PJ, Key EL (2008) Comparisons of shipboard infrared sea surface skin temperature measurements from the CIRIMS and the M-AERI. J Atmos Ocean Tech
25:589–606