Sea surface temperature from AVHRR

The SST observations off the coast of California. Warm areas are shown to be red and colder areas are in blue. The blue colored filaments near the coast indicate cold water being pulled out from the bottom. Copyright: UHH/CEN/AJB

Topics

Access

UNRESTRICTED:

Version 5.0: Get data (hdf) via anonymous ftp at PODAAC
Version 5.2: Get data (netCDF) via anonymous ftp from NODC

RESTRICTED: This link to the data set is only available for a restricted user group. The data set is only accessible in CEN/MPI net or accessible from external nets with a customer account. Please contact ICDC if you would like to access this data from outside the network.

Data access via file system: /data/icdc/ocean/pathfinder_sst_v5.2

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Description

This is data of a new re-analysis of the AVHRR data archive, developed within the "AVHRR Pathfinder Version 5 SST Project (Pathfinder V5)" at Rosenstiel School of Marine and Atmospheric Science (RSMAS), University of Miami, Fl, NOAA National Oceanographic Data Center (NODC), and NASA Physical Oceanography Distributed Active Archive Center (PO.DAAC). A new version of the Pathfinder Algorithm is used, that allows, among others, the retrieval of twice-daily global SST maps. Important improvements are the more accurate landmask, a finer spatial resolution (4 km instead of 9 km) and the inclusion of sea ice information. Additionally, data quality flags have been improved, e.g. with regard to the aerosol influence.

Trends in sea surface temperatures from 1985-2009 derived from AVHRR Pathfinder v.5 data sets. The trends are shown in percent for the selected regions (in boxes of approx. 10 x 20 degrees). Generally, a (positive) warming trend of the ocean can be seen.

This is version 5.2! The official name of this data set is "AVHRR Pathfinder Version 5.2 L3-Collated (L3C) sea surface temperature".

Important: For cloudy areas no SST values can be retrieved; here particularly the data set with daily resolution contains numerous gaps. Still it is the daily data we are offering here - separately for day and night overpasses. Monthly average SST data will be generated and provided later.

Last update of data set at ICDC: July 29, 2014.

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Parameters

Parameters of the SST data set
Name	Unit / Comment
SST	°C (sea surface temperature)
dt_analysis	°C (Difference to SST of previous day)
Wind speed	m/s (NCEP/DOE AMIP-II Reanalysis)
Sea ice fraction	0 ... 1 (entweder OSI-SAF or L4 GHRSST DailyOI SST product)
ADI	none (Indicator for atmospheric optical depth)
quality level	none (GDS2 conform flags, 0 (missing data) ... 5 (best quality))
pf quality level	none (original Pathfinder quality flags)
Level 2 data flag	none (Bit-Flag about surface type distribution)

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Coverage, spatial and temporal resolution

Period and temporal resolution:

01-11-1981 to 31-12-2012
Daily, separately for day and night overpasses

Coverage and spatial resolution:

Global
Spatial resolution: 4 km x 4 km, cartesian grid
Geographic latitude: -90.0°N to 90.0°N
Geographic longitude: -180°E to 180.0°E
Dimension: 4320 rows x 8640 columns
Altitude: 0.0 m

Format:

NetCDF

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Data quality

In contrast to version 5.0 of this data set the new version 5.2 does not include an estimate of the standard deviation of the SST for each grid cell. Only the quality flags and the difference to the sst of the previous day give a measure of the quality. It is planned that in Version 6.0 this caveat will be removed.

More information is given on the corresponding website at NODC , at the GHRSST Project Office website, in Kilpatrick et al. (2001) and in Casey et al. (see references).

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Contact

Kenneth S. Casey, NODC Satellite Oceanography Group
email: Kenneth.Casey (at) noaa.gov

GHRSST Project Office
email: ghrsst-po (at) nceao.ac.uk

Stefan Kern
ICDC / CEN / University of Hamburg
E-Mail: stefan.kern"AT"uni-hamburg.de

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References

Literature:

Kilpatrick, K. A., Podestá, G. P., and Evans, R. (2001), Overview of the NOAA/NASA advanced very high resolution radiometer Pathfinder algorithm for sea surface temperature and associated matchup database, J. Geophys. Res., 106( C5), 9179– 9197, doi:10.1029/1999JC000065. https://doi.org/10.1029/1999JC000065
Casey, K.S., T.B. Brandon, P. Cornillon, and R. Evans: The Past, Present and Future of the AVHRR Pathfinder SST Program, in Oceanography from Space: Revisited, eds. V. Barale, J.F.R. Gower, and L. Alberotanza, Springer, 2010. DOI: 10.1007/978-90-481-8681-5_16. https://doi.org/10.1007/978-90-481-8681-5_16

Websites:

NODC - Information about the data, a User Guide, tools, and data quality, avhrr-pathfinder-sst, NOAA, https://www.ncei.noaa.gov/products/avhrr-pathfinder-sst
GHRSST Project Office, http://www.ghrsst.org/
PODAAC - General informationen to this data set, https://podaac.jpl.nasa.gov/

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Data citation, License, and Acknowledgments

Please cite the data as follows:

Version 5.2:

Casey, Kenneth S.; Evans, Robert H.; Baringer, Warner; Kilpatrick, Katherine A.; Podestá, Guillermo P.; Walsh, Susan; Williams, Elizabeth; Brandon, Tess B.; Byrne, Deirdre A.; Foti, Gregg; Li, Yuanjie; Phillips, Sheri A.; Zhang, Dexin; Zhang, Yongsheng (2011). AVHRR Pathfinder version 5.2 level 3 collated (L3C) global 4km sea surface temperature for 1981-2012. [indicate subset used]. NOAA National Centers for Environmental Information. Dataset. https://doi.org/10.7289/v5wd3xhb. Accessed [date].

Version 5.0:

NODC and Rosenstiel School of Marine and Atmospheric Science. 2003. AVHRR Pathfinder Level 3 Monthly Nighttime SST Version 5. Ver. 5. PO.DAAC, CA, USA. Dataset accessed [YYYY-MM-DD] at https://doi.org/10.5067/PATHF-MON50
Distributed in netCDF format by the Integrated Climate Data Center (ICDC), CEN, University of Hamburg, Hamburg, Germany.

and with the following acknowledgments:

Thanks to ICDC, CEN, University of Hamburg for data support.

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