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Dataset Overview | National Centers for Environmental Information (NCEI)

AVHRR Pathfinder version 5.0 and 5.1 4km global sea surface temperature (SST) 5-day harmonic climatologies for 1982-2008 (NCEI Accession 0071182)

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This dataset contains a global, 4km 5-day sea surface temperature climatology derived from harmonic analysis of the AVHRR Pathfinder Version 5.0 and 5.1 sea surface temperature time series data for 1982-2008. The climatology is available as 73 separate files, each representing a 'pentad,' or 5-day period, in a climatological year. The files are in netCDF-4 and fully comply with the GHRSST Data Specification 2.0 for Level 4 products. In addition to climatological sea surface temperature, each file contains standard deviation, sea ice concentration, sea ice concentration error, and land mask information.

This dataset also includes a 'classic,' or mean, 5-day sea surface temperature climatology derived from the same Pathfinder time series data. This climatology was used to gap-fill the harmonic climatology, and provided the standard deviation information. It is available as 73 separate files in Hierarchical Data Format Version 4 (HDF4).

In some ice-dominated high-latitude areas, the harmonic climatology is poorly constrained due to uneven distribution throughout the year of the valid measurements. For example, at 67.5S, 73W near the Antarctic coast, temperatures estimated in the harmonic climatology reach almost 40C. In these regions, the classic, averaged climatological values may be more reliable.

Associated daily and monthly harmonic climatologies are archived at NCEI under accessions 0071181 and 0075098, respectively.
  • Cite as: Casey, Kenneth S.; Kearns, Edward J.; Halliwell, Vicki; Evans, Robert (2011). AVHRR Pathfinder version 5.0 and 5.1 4km global sea surface temperature (SST) 5-day harmonic climatologies for 1982-2008 (NCEI Accession 0071182). [indicate subset used]. NOAA National Centers for Environmental Information. Dataset. https://www.ncei.noaa.gov/archive/accession/0071182. Accessed [date].
  • Please refer to Credit tab for full citation information.
gov.noaa.nodc:0071182
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  • HTTPS (download)
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  • FTP (download)
    These data are available through the File Transfer Protocol (FTP). FTP is no longer supported by most internet browsers. You may copy and paste the FTP link to the data into an FTP client (e.g., FileZilla or WinSCP).
Distribution Formats
  • netCDF (Version: netCDF-4 classic model)
    • File Specification: GDS-2.0, CF-1.5, Unidata Dataset Discovery v1.0
  • HDF (Version: 20080214)
    • File Specification: NCSA Hierarchical Data Format (HDF 4), Scientific Data Set (HDF-SDS)
Ordering Instructions Contact NCEI for other distribution options and instructions.
Distributor NOAA National Centers for Environmental Information
+1-301-713-3277
NCEI.Info@noaa.gov
Dataset Point of Contact NOAA National Centers for Environmental Information
ncei.info@noaa.gov
Time Period 1982-01-01 to 2008-12-31
Spatial Bounding Box Coordinates
West: -180
East: 180
South: -90
North: 90
Spatial Coverage Map
General Documentation
Associated Resources
  • AVHRR Pathfinder version 5.0 and 5.1 global 4km sea surface temperature (SST) daily, 5-day, and monthly harmonic climatologies for 1982-2008
    • NCEI Collection
      Navigate directly to the URL for data access and direct download.
  • NASA/Jet Propulsion Laboratory Physical Oceanography Distributed Active Archive Center (DAAC)
  • NOAA Climate Data Record Program
  • The Past, Present, and Future of the AVHRR Pathfinder SST Program. In Barale, Vittorio, Gower, J.F.R., Alberotanza, L. (Eds.), Oceanography from Space: Revisited
  • Casey, Kenneth S.; Kearns, Edward J.; Halliwell, Vicki; Evans, Robert (2004). AVHRR Pathfinder version 5.0, interim version 5.0, and version 5.1 global 4km sea surface temperature (SST) data for 1981-2009. NOAA National Centers for Environmental Information. Dataset. https://www.ncei.noaa.gov/archive/accession/AVHRR_Pathfinder-NODC-v5.0_v5.1.
  • Casey, Kenneth S.; Kearns, Edward J.; Halliwell, Vicki; Evans, Robert (2011). AVHRR Pathfinder version 5.0 and 5.1 global 4km sea surface temperature (SST) daily harmonic climatologies for 1982-2008 (NCEI Accession 0071181). NOAA National Centers for Environmental Information. Dataset. https://www.ncei.noaa.gov/archive/accession/0071181.
  • Casey, Kenneth S.; Kearns, Edward J.; Halliwell, Vicki; Evans, Robert (2011). AVHRR Pathfinder version 5.0 and 5.1 4km global sea surface temperature (SST) monthly harmonic climatologies for 1982-2008 (NCEI Accession 0075098). NOAA National Centers for Environmental Information. Dataset. https://www.ncei.noaa.gov/archive/accession/0075098.
  • Casey, Kenneth S.; Kearns, Edward J.; Halliwell, Vicki; Evans, Robert (2013). AVHRR Pathfinder version 5.0 global 4km sea surface temperature (SST) cloud-screened monthly climatologies for 1985-2006 (NCEI Accession 0110657). NOAA National Centers for Environmental Information. Dataset. https://www.ncei.noaa.gov/archive/accession/0110657.
  • Casey, Kenneth S.; Kearns, Edward J.; Halliwell, Vicki; Evans, Robert (2004). AVHRR Pathfinder version 5.0 global 4km sea surface temperature (SST) climatologies for 1985-2001. NOAA National Centers for Environmental Information. Dataset. https://www.ncei.noaa.gov/archive/accession/AVHRR_Pathfinder-NODC-v5.0-climatologies.
  • NOAA Polar Orbiter Data User's Guide
  • Parent ID (indicates this dataset is related to other data):
    • gov.noaa.nodc:AVHRR_Pathfinder-NODC-v5.0_v5.1-climatologies
Publication Dates
  • publication: 2011-06-29
  • revision: 2022-01-11
Data Presentation Form Digital table - digital representation of facts or figures systematically displayed, especially in columns
Dataset Progress Status Complete - production of the data has been completed
Historical archive - data has been stored in an offline storage facility
Data Update Frequency As needed
Supplemental Information
The procedure used to generate this 5-day harmonic climatology can be broken down into two primary components:

1. Harmonic analysis of time series data

The harmonic climatology is created by fitting to a time series of SST data at each pixel a cosine function containing both annual and semi-annual components:

SST = A * cos(2pi*t + B) + C * cos(4pi*t + D) + E

The constants A and B correspond to the annual amplitude and annual phase, respectively. The constants C and D correspond to the semi-annual amplitude and phase. The constant E is the long term mean at that pixel.

The input time series consists of pentad (5-day) averages of best-quality data (quality flag 7) only for 1982-2008. These data are archived by NCEI in separate yearly accessions.

To create a gap-free data set for analysis, median spatial fill routines are applied to each 5-day global SST average in the time series. Using a curve-fitting tool in Matlab (lsqcurvefit.m), the cosine function is fit to the SST time series and the five harmonic constants are calculated. Note: If fewer than 100 good observations are available for a given pixel, the amplitudes (A and C) are set to zero, phases (B and D) set to one, and the long term mean (E) is set to the mean at that pixel.

2. Application of harmonic parameters

The five harmonic constants can then be plugged into the cosine function to solve for sea surface temperature at any temporal resolution. In this case, the constants are applied at a 5-day resolution to calculate sea surface temperature for 73 pentads in a climatological year. For pixels missing SST values, where the harmonic analysis failed to converge to a solution, median spatial fill routines are applied. Any remaining pixels with missing values after median filling are filled using SST values from the classic climatology.

File-naming convention for 5day harmonic climatology files:
[0000][MMDD][HHMMSS]-NODC-L4_GHRSST-SSTskin-AVHRR_Pathfinder-PFV5.0_5day_Climatology_1982_2008_DayNightCombined-v02.0-fv[##.#].nc

0000 - representative year of analysis (climatological year)
MMDD - representative month and day of analysis, e.g. 0630 for June 30 of the climatological year
HHMMSS - representative time (6-digit hour, minute and second) of analysis.
##.# - file version, e.g. 01.0
Purpose To provide daily day-night combined climatologies of SST with high accuracy and high spatial resolution.
Use Limitations
  • accessLevel: Public
  • Distribution liability: NOAA and NCEI make no warranty, expressed or implied, regarding these data, nor does the fact of distribution constitute such a warranty. NOAA and NCEI cannot assume liability for any damages caused by any errors or omissions in these data. If appropriate, NCEI can only certify that the data it distributes are an authentic copy of the records that were accepted for inclusion in the NCEI archives.
Dataset Citation
  • Cite as: Casey, Kenneth S.; Kearns, Edward J.; Halliwell, Vicki; Evans, Robert (2011). AVHRR Pathfinder version 5.0 and 5.1 4km global sea surface temperature (SST) 5-day harmonic climatologies for 1982-2008 (NCEI Accession 0071182). [indicate subset used]. NOAA National Centers for Environmental Information. Dataset. https://www.ncei.noaa.gov/archive/accession/0071182. Accessed [date].
  • Please also cite: Casey, K.S., T.B. Brandon, P. Cornillon, and R. Evans (2010). "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. https://doi.org/10.1007/978-90-481-8681-5_16
Cited Authors
Contributors
Resource Providers
Publishers
Theme keywords NODC DATA TYPES THESAURUS NODC OBSERVATION TYPES THESAURUS WMO_CategoryCode
  • climatology
  • satelliteObservation
GHRSST Project Science Keywords
  • EARTH SCIENCE > Oceans > Ocean Temperature > Sea Surface Temperature > AVHRR
  • EARTH SCIENCE > Oceans > Ocean Temperature > Sea Surface Temperature > AVHRR > 4km Pathfinder
Global Change Master Directory (GCMD) Science Keywords
Data Center keywords NODC COLLECTING INSTITUTION NAMES THESAURUS NODC SUBMITTING INSTITUTION NAMES THESAURUS Global Change Master Directory (GCMD) Data Center Keywords
Platform keywords NODC PLATFORM NAMES THESAURUS Global Change Master Directory (GCMD) Platform Keywords ICES/SeaDataNet Ship Codes
Instrument keywords NODC INSTRUMENT TYPES THESAURUS Global Change Master Directory (GCMD) Instrument Keywords
Place keywords NODC SEA AREA NAMES THESAURUS Global Change Master Directory (GCMD) Location Keywords
Project keywords NODC PROJECT NAMES THESAURUS Global Change Master Directory (GCMD) Project Keywords
Keywords NCEI ACCESSION NUMBER
Use Constraints
  • Cite as: Casey, Kenneth S.; Kearns, Edward J.; Halliwell, Vicki; Evans, Robert (2011). AVHRR Pathfinder version 5.0 and 5.1 4km global sea surface temperature (SST) 5-day harmonic climatologies for 1982-2008 (NCEI Accession 0071182). [indicate subset used]. NOAA National Centers for Environmental Information. Dataset. https://www.ncei.noaa.gov/archive/accession/0071182. Accessed [date].
  • Please also cite: Casey, K.S., T.B. Brandon, P. Cornillon, and R. Evans (2010). "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. https://doi.org/10.1007/978-90-481-8681-5_16
Access Constraints
  • Use liability: NOAA and NCEI cannot provide any warranty as to the accuracy, reliability, or completeness of furnished data. Users assume responsibility to determine the usability of these data. The user is responsible for the results of any application of this data for other than its intended purpose.
Fees
  • In most cases, electronic downloads of the data are free. However, fees may apply for custom orders, data certifications, copies of analog materials, and data distribution on physical media.
Lineage information for: dataset
Processing Steps
  • 2011-06-29T01:04:45Z - NCEI Accession 0071182 v1.1 was published.
  • 2022-01-11T21:16:08Z - NCEI Accession 0071182 was revised and v1.2 was published.
    Rationale: Additional metadata files were received or created for this dataset. These updates were copied into the about/ directory of this accession. These updates may provide additional files or replace obsolete files. This version contains the most complete and up-to-date representation of this archival information package. All of the files received prior to this update are available in the preceding version of this accession.
Output Datasets
Lineage information for: repository
Processing Steps
  • 2015-04-22T00:00:00 - NOAA created the National Centers for Environmental Information (NCEI) by merging NOAA's National Climatic Data Center (NCDC), National Geophysical Data Center (NGDC), and National Oceanographic Data Center (NODC), including the National Coastal Data Development Center (NCDDC), per the Consolidated and Further Continuing Appropriations Act, 2015, Public Law 113-235. NCEI launched publicly on April 22, 2015.
Acquisition Information (collection)
Instrument
  • AVHRR-2
  • AVHRR-3
Platform
  • NOAA-11
  • NOAA-14
  • NOAA-16
  • NOAA-17
  • NOAA-18
  • NOAA-7
  • NOAA-9
Last Modified: 2023-11-15T16:15:08Z
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