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OAS accession Detail for 0197564
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| accessions_id: | 0197564 | archive |
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| Title: | The Coral Reef Temperature Anomaly Database (CoRTAD) Version 6 - Global, 4 km Weekly-Averaged SST time series, with gaps due to clouds, for 1982 to 2018 (NCEI Accession 0197564) |
| Abstract: | This dataset contains the Weekly-Averaged SST time series, with gaps due to clouds, from the Coral Reef Temperature Anomaly Database (CoRTAD) Version 6. CoRTAD Version 6 is a global, 4 km, sea surface temperature (SST) and related thermal stress metrics dataset for 1982-01-02 to 2018-12-28. The CoRTAD contains weekly-averaged SSTs, SST anomaly (SSTA, weekly SST minus weekly climatological SST), thermal stress anomaly (TSA, weekly SST minus the maximum weekly climatological SST), SSTA Degree Heating Week (SSTA_DHW, sum of previous 12 weeks when SSTA is greater than or equal to 1 degree C), SSTA Frequency (number of times over previous 52 weeks that SSTA is greater than or equal to 1 degree C), TSA DHW (TSA_DHW, also known as a Degree Heating Week, sum of previous 12 weeks when TSA is greater than or equal to 1 degree C), and TSA Frequency (number of times over previous 52 weeks that TSA is greater than or equal to 1 degree C). In addition, the CoRTAD includes ancillary sea ice concentration and marine wind speed data. These data are the sixth in the series of CoRTAD datasets originally created in association with Elizabeth Selig (Director, Marine Science, Conservation International) and John Bruno (University of North Carolina; UNC - Chapel Hill). This dataset is based on the Pathfinder V5.3 dataset, and is created with support from the NOAA Coral Reef Conservation Program. |
| Date received: | 20190731 |
| Start date: | 19820102 |
| End date: | 20181228 |
| Seanames: | World-Wide Distribution |
| West boundary: | -180 |
| East boundary: | 180 |
| North boundary: | 90 |
| South boundary: | -90 |
| Observation types: | physical, satellite data |
| Instrument types: | AVHRR-2, AVHRR-3 |
| Datatypes: | ICE - COVERAGE, SEA SURFACE TEMPERATURE, WATER TEMPERATURE, WIND SPEED |
| Submitter: | Casey, Dr. Kenneth S. |
| Submitting institution: | US DOC; NOAA; NESDIS; National Centers for Environmental Information |
| Collecting institutions: | US DOC; NOAA; NESDIS; National Centers for Environmental Information |
| Contributing projects: | COASTAL, CORAL REEF STUDIES, CoRIS |
| Platforms: | NOAA-11 (3101), NOAA-14 (3277), NOAA-16 (33J9), NOAA-17 (33ZS), NOAA-18 (33WM), NOAA-19 (33Y9), NOAA-7 (33V2), NOAA-9 (33OO) |
| Number of observations: | |
| Supplementary information: | [Text below adapted from: Selig, E.R., K.S. Casey, and J.F. Bruno (2010). New insights into global patterns of ocean temperature anomalies: implications for coral reef health and management, Global Ecology and Biogeography, https://doi.org/10.1111/j.1466-8238.2009.00522.x. Hereafter referred to as "SCB2010".] The CoRTAD version 6 was developed using 1982-2018 data from the Pathfinder Version 5.3 collection (Saha et al., 2018) produced by the National Oceanic and Atmospheric Administration's (NOAA) National Centers for Environmental Information (NCEI). These sea surface temperature data are derived from the Advanced Very High Resolution Radiometer (AVHRR) sensor and are processed to a resolution of approximately 4.6 km at the equator. These data have the highest resolution covering the longest time period of any satellite-based ocean temperature dataset. Daytime and nighttime data were averaged weekly using data with a quality flag of 4 or better. This level is a commonly accepted cutoff for "good" data (Kilpatrick et al., 2001, Casey and Cornillon, 1999). Previous versions of CoRTAD (versions 1-3) also incorporated pixels up to 5 degrees warmer than a course resolution reference SST based on the Reynolds Optimum Interpolation Sea Surface Temperature (Weekly, 1-degree OISST version 2.0). Since Pathfinder Version 5.3 already uses a finer resolution reference field (25 km Daily OISST) this additional step was not incorporated here in CoRTAD (for later Versions 4-6) (Casey et al., 2012). These processes resulted in a weekly SST dataset that is roughly 80% gap free. To create a gap-free dataset for analysis, 3 x 3 pixel median spatial fill was used. A temporal fill was then performed using the nonlinear least squares data fitting (Levenberg-Marquardt algorithm) in SLATEC Common Mathematical Library (in public domain) to fill the remaining gaps. This conservative approach was chosen because it provided interpolated SSTs that are bounded by the nearest available values in time. It also used data from only a very limited spatial domain, which is an important consideration given the variability of coral reef environments. Using these gap-filled data, we then created site-specific climatologies for each reef grid cell to describe long-term temperature patterns over the 35-year dataset. The climatology was generated using a harmonic analysis procedure that fits annual and semi-annual signals to the time series of weekly SSTs at each grid cell: climSST(t) = A*cos(2pi*t + B) + C*cos(4pi*t + D) + E (1), where t is time, A and B are coefficients representing the annual amplitude and phase, C and D are the semi-annual amplitude and phase, and E is the long-term temperature mean. Others have used similar approaches for generating climatologies because they are more robust than simple averaging techniques, which can be more susceptible to data gaps from periods of cloudiness (Podesta et al., 1991, Mesias et al., 2007). Please note in CoRTAD Versions 4 to 6, a gap exists in the Pathfinder 5.3 dataset from 1994 day 275 to 1995 day 17 since Level 1B GAC data from NOAA-9 is not available from the NOAA archives. For these 3.5 months SST has been interpolated from Pathfinder 5.0 and 0.17K is subtracted to transform the data to the skin temperature basis of Pathfinder Version 5.3. Similar to Version 5, CoRTAD version 6 data are not stored in separate geographic tiles as was the case for version 4 and its predecessors. Instead, each data file contains the entire global coverage for a related grouping of CoRTAD parameters. Following are the version changes at glance: Version 6, 1982-01-02 - 2018-12-28, Global 4320x8640x1930 netCDF-4.2.1.1 Version 5, 1982-01-02 - 2012-12-28, Global 4320x8640x1617 netCDF-4.1.2 Version 4, 1981-10-31 - 2010-12-31, Global 4320x8640, Tile 540x540, netCDF-4 Classic Version 3, 1982-01-01 - 2009-12-31, Global 4096x8192, Tile 512x512, HDF5 Version 2, 1982-01-01 - 2008-12-31, Global 4096x8192, Tile 512x512, HDF5 Version 1, 1985-01-01 - 2005-12-31, Global 4096x8192, Tile 512x512, HDF4 NCEI Accession Numbers: v5 0126774; v4 0087989; v3 0068999; v2 0054501; v1 0044419 |
| Availability date: | |
| Metadata version: | 2 |
| Keydate: | 2019-08-15 17:50:05+00 |
| Editdate: | 2023-10-06 17:06:35+00 |