Daily 5km Satellite Coral Bleaching Heat Stress Monitoring
(Version 3, released on 4 May 2017)

Click on buttons below image to change parameter; click on image to view larger, tiled images.

Current Regional Images
Alert Area (7-day max):  45 | Global | East | West | Pac | Ind | S.Atl | Coral Triangle [big] | Caribbean [big] | Florida | Hawaii | GBR
Hotspot:  45 | Global | East | West | Pac | Ind | S.Atl | Coral Triangle [big] | Caribbean [big] | Florida | Hawaii | GBR
DHW:  45 | Global | East | West | Pac | Ind | S.Atl | Coral Triangle [big] | Caribbean [big] | Florida | Hawaii | GBR
SST:  45 | Global | East | West | Pac | Ind | S.Atl | Coral Triangle [big] | Caribbean [big] | Florida | Hawaii | GBR
SST Anomaly:  45 | Global | East | West | Pac | Ind | S.Atl | Coral Triangle [big] | Caribbean [big] | Florida | Hawaii | GBR
SST Trend (over 7 days):  45 | Global | East | West | Pac | Ind | S.Atl | Coral Triangle [big] | Caribbean [big] | Florida | Hawaii | GBR
   
4-Month Outlook (60%) 45 | Global | East | West | Pac | Ind | S.Atl | Coral Triangle [big] | Caribbean [big] | Florida | Hawaii | GBR


Most Recent 30-day Animations
Alert Area (7-day max):  45ns | Global | East | West | Pac | Ind | S.Atl | Coral Triangle | Caribbean | Florida | Hawaii | GBR
Hotspot:  45ns | Global | East | West | Pac | Ind | S.Atl | Coral Triangle | Caribbean | Florida | Hawaii | GBR
DHW:  45ns | Global | East | West | Pac | Ind | S.Atl | Coral Triangle | Caribbean | Florida | Hawaii | GBR
SST:  45ns | Global | East | West | Pac | Ind | S.Atl | Coral Triangle | Caribbean | Florida | Hawaii | GBR
SST Anomaly:  45ns | Global | East | West | Pac | Ind | S.Atl | Coral Triangle | Caribbean | Florida | Hawaii | GBR
SST Trend (over 7 days):  45ns | Global | East | West | Pac | Ind | S.Atl | Coral Triangle | Caribbean | Florida | Hawaii | GBR

Most Recent 90-day Animations
Alert Area (7-day max):  45ns | Global | East | West | Pac | Ind | S.Atl | Coral Triangle | Caribbean | Florida | Hawaii | GBR
Hotspot:  45ns | Global | East | West | Pac | Ind | S.Atl | Coral Triangle | Caribbean | Florida | Hawaii | GBR
DHW:  45ns | Global | East | West | Pac | Ind | S.Atl | Coral Triangle | Caribbean | Florida | Hawaii | GBR
SST:  45ns | Global | East | West | Pac | Ind | S.Atl | Coral Triangle | Caribbean | Florida | Hawaii | GBR
SST Anomaly:  45ns | Global | East | West | Pac | Ind | S.Atl | Coral Triangle | Caribbean | Florida | Hawaii | GBR
SST Trend (over 7 days):  45ns | Global | East | West | Pac | Ind | S.Atl | Coral Triangle | Caribbean | Florida | Hawaii | GBR


Archived Data and Images
(1 January 2018 - present)

Global and Regional Images:
60x40-degree tiled images (small, 720x540) (see description of tiles)
60x40-degree tiled images (large, 2160x1620) (see description of tiles)
Data Access via FTP Server:
NetCDF4 Data+   BAA* (7-d max) | BAA (single-day) | HotSpot | DHW | SSTA* | SST | SST Trend (7-day)
Images (pixels)   BAA* (7-d max) | BAA (single-day) | HotSpot | DHW | SSTA* | SST | SST Trend (7-day)
Images (browse)   BAA* (7-d max) | BAA (single-day) | HotSpot | DHW | SSTA* | SST | SST Trend (7-day)

+ CDAT software for viewing CRW NetCDF data files.
* BAA: Bleaching Alert Area; SSTA: SST Anomaly.


  


Archived Data and Images
(1985 - 2017)

CRW Daily Global 5km Product Suite Version 3.1 (see Special Notice below for details)



Climatology**: NetCDF4 file   |   Pixel Images   |     (CDAT software for viewing CRW NetCDF data files)
** Contains 12 monthly mean SST climatologies for deriving the SST Anomaly product, and the Maximum Monthly Mean (MMM) SST Climatology for deriving NOAA CRW's coral bleaching heat stress products.




 
Special Notice
NOAA Coral Reef Watch just released Phase I of its version 3.1 (v3.1) daily global 5km (0.05-degree) satellite coral bleaching heat stress monitoring product suite: a historical dataset for 1985-2017. In addition to a substantial number of users having requested that CRW produce a historical 5km satellite dataset, some errors were identified in the near real-time source SST data for CRW's Version 3.0 (v3.0) products (presented on this webpage) for some coral reef regions at various times during 2013-2016, and a replacement dataset for that time period was needed. To address these needs, CRW developed CoralTemp v1.0, and from that dataset derived the newly-released v3.1 coral bleaching heat stress monitoring product suite. Phase I of the v3.1 product suite, released on April 11, 2018, is historical only, covering 1985-2017. Phase II (yet to be implemented) will provide an up-to-date data stream, also derived from CoralTemp v1.0, covering January 1, 2018 to the present. Once Phase II is complete, v3.1 of the heat stress product suite will span 1985 to the present and will replace this v3.0 suite completely. In the interim, users can access this v3.0 product suite, from January 1, 2018 to the present, for continuation of the v3.1 historical products. Note that the v3.1 suite applies the same algorithm and climatology as v3.0.

 

Product Suite Description

The NOAA Coral Reef Watch (CRW) experimental daily global 5km (0.05-degree) satellite coral bleaching heat stress monitoring product suite presented here is the third version (Version 3 or v3.0). It provides service at or near reef-scales, allowing direct monitoring of 95% of global coral reefs and significantly reducing data gaps caused by cloud cover. This 5km suite, which now comprises the core of CRW's next-generation Decision Support System (DSS) for coral bleaching management, is based on the NOAA/NESDIS operational daily global 5km geostationary-polar-orbiting (Geo-Polar) Blended Night-only SST Analysis.


A significantly improved climatology was introduced in the v3.0 products. It was derived from a combination of NOAA/NESDIS' 2002-2012 reprocessed daily global 5km Geo-Polar Blended Night-only SST Analysis and the 1985-2002 daily global 5km nighttime SST reanalysis, produced by the United Kingdom Met Office, on the Operational SST and Sea Ice Analysis (OSTIA) system. On September 21, 2015, NESDIS' operational daily 5km Blended Night-only SST that CRW's 5km coral bleaching heat stress monitoring product suite is based on switched to using the near real-time OSTIA as the bias correction. Hence, the 2002-2012 reprocessed 5km Geo-Polar Blended Night-only SST that became available in October 2016, extended with the 1985-2002 portion of the 5km OSTIA nighttime SST reanalysis, is the best historical 1985-2012 global nighttime SST dataset for deriving a climatology that is internally consistent and compatible with CRW's near real-time 5km satellite coral bleaching heat stress monitoring products. Although the reprocessed 5km Geo-Polar Blended SST dataset is available to the end of 2016, to be consistent with the time period (1985-2012) of the climatology used in CRW's Version 2 (v2.0) 5km product suite, the v3.0 climatology is based on the same time period. It was then re-centered to the center of the baseline time period of 1985-1990 plus 1993, using the method described in Heron et al. (2015) and Liu et al. (2014), and was based on CRW's monitoring algorithm (also described in these articles). More recent years may be incorporated in the climatology for future versions of CRW's 5 km products, but potential impacts on the products require further evaluation first.

Note that the climatology used for CRW's v2.0 5km products was produced using night-only values for the 28-year period, 1985-2012, from the 4km Advanced Very High Resolution Radiometer (AVHRR) Pathfinder Version 5.2 SST (PFV5.2) dataset, an official NOAA climate data record. At the time the v2.0 product suite was developed, PFV5.2 was the highest quality historical daily global SST available, with a spatial resolution (4km) close to the desired 5km resolution. However, the gappy daily PSFV.2 SST introduced warm bias in the resulting climatology, causing an underestimation of coral bleaching heat stress in many reef regions worldwide. (Evolution of CRW's next-generation daily global 5km product suites, including a more detailed description of the v2.0 suite, can be found here.)


Current CRW 5km products include sea surface temperature (SST), SST Anomaly, Coral Bleaching HotSpot, Degree Heating Week (DHW), a 7-day maximum Bleaching Alert Area, and a 7-day SST Trend. CRW also has a 5km Regional Virtual Stations/Bleaching Heat Stress Gauges product and a free, automated 5km Bleaching Alert Email System that are based on this product suite.

SST variability is often considerably higher at the much finer 5km spatial and daily temporal resolutions, when compared with CRW's heritage operational twice-weekly 50km (0.5-degree) monitoring product suite. Due to resulting day-to-day fluctuations between stress levels in highly-variable locations, the single-day 5km Bleaching Alert Area product does not consistently and adequately identify potentially harmful heat stress levels, especially with regard to the impact of accumulated heat stress. Rather than requiring users to examine the single-day 5km Bleaching Alert Area product over several days, a 7-day maximum Bleaching Alert Area composite product, updated daily, was introduced in the v2.0 product suite and is maintained here in v3.0. This 7-day composite product shows the maximum stress level that a satellite pixel has experienced during the most recent seven (7) consecutive days. Data and images are dated on the last day of the 7-day period. Additionally, the 5km 7-day maximum Bleaching Alert Area composite product is compatible with CRW's operational 50km twice-weekly Bleaching Alert Area product. (The 50km Bleaching Alert Area product is actually based on a half-week (3 or 4 days) composite of 50km SSTs, but with much less SST variability due to its much coarser spatial resolution.)

The daily 5km 7-day SST Trend provides information on the pace and direction of the SST variation and thus coral bleaching heat stress, if present, over the past seven days. Seven daily global SSTs are included in the calculation. Pixels colored in green have insignificant trends, due either to small SST trends (within the range -0.2 to 0.2 °C) or trends that failed the two-tailed Student's-t test for the 20% significance level with five degrees of freedom.

All other v3.0 5km products presented here are single-day products, updated daily. The latest products will be for the date 1-2 days prior to the current date, however, as data are processed in the early afternoon, U.S. Eastern Time, using data from the previous day. For example, data processed on a Wednesday afternoon will include all observations made on Tuesday (independent of time zone) and will carry Tuesday's date.


For additional technical details about the 5-km product suite, see Liu et al. 2014.


This v3.0 suite was released on May 4, 2017, along with a new version of CRW's 5km Regional Virtual Stations/Bleaching Heat Stress Gauges product. V2.0 of the 5km product suite (that v3.0 replaces) was released on May 5, 2014, and Version 1 (v1.0) was released on July 5, 2012 (based on NESDIS' operational daily global 5km Geo-Polar Blended Day-Night SST Analysis and an earlier version of the climatology derived from the PFV5.2).

CRW's first-generation (heritage) product suite -- the aforementioned operational twice-weekly 50km (0.5-degree) monitoring product suite -- has provided 20+ years of successful satellite-based monitoring of coral reef ecosystem environmental conditions to global reef communities since 1997. CRW will continue to produce the 50km products until the 5km suite becomes operational. There are some differences between the two product suites in certain areas of the globe, and user discretion is advised. We have found the 5km product suite is more accurate due to the improved data quality, density, spatial and temporal resolutions, and climatology. Improvements of the 5km products over the heritage 50km products are due to CRW's use of a next-generation, higher quality SST analysis; a next-generation SST algorithm, based on multiple satellites/sensors; and an improved climatology.


Development of this next-generation 5km product suite was accomplished through a collaboration of NOAA Coral Reef Watch, the University of South Florida, NASA-Ames, the UNEP World Conservation Monitoring Centre, and the Cooperative Institute for Research in Environmental Science, with funding support from the NASA Biodiversity and Ecological Forecasting program, the NOAA Coral Reef Conservation Program, and the NOAA/NESDIS Ocean Remote Sensing Program. Production of the Version 3 suite was made possible through funding from the NOAA Coral Reef Conservation Program. The 5km product suite, which was featured in the NASA Applied Sciences Program's 2013 Annual Report, will undergo continuous improvements.

 



CRW Operational Twice-weekly 50km Product Suite