Time between Severe Heat Stress Events (NOAA, 2019)

This dataset shows the frequency and intensity of heat stress events. Heat stress events can be detected using sea surface temperature (SST), which is the water temperature close to the ocean's surface. A heat stress event occurs when the SST near coral reefs exceeds the historical baseline for that area. This dataset describes the average period between severe heat stress events, where the Daily Heating Week (DHW) value was greater than or equal to 8, from 1985-2018 at a 5 kilometer (km) resolution. Shows 0.0 if no such events occurred.

Stress events are defined by applying Coral Reef Watch's Degree Heating Week (DHW) methodology [https://coralreefwatch.noaa.gov/satellite/education/tutorial/crw24_dhw_product.php] at coral reef-containing and adjacent satellite pixel locations worldwide. The DHW attempts to capture both the level of abnormal heating and its duration: 1 DHW is equivalent to 1 week of SST 1°C above the expected summertime maximum at a given location. The three thresholds for heat stress in this dataset correspond to occurrence (DHW>0), significant coral bleaching (DHW≥4), and widespread bleaching and significant mortality (DHW≥8).

SST and its fluctuations are critical to ecosystem dynamics and health, as many marine organisms can thrive only within certain temperature ranges. In particular, research indicates that a coral reef’s “thermal history” is among the most important factors influencing its ability to withstand heat stress events. Accordingly, with support from the National Oceanic and Atmospheric Administration (NOAA) Coral Reef Conservation Program, Coral Reef Watch (CRW) [https://coralreef.noaa.gov/] developed a variety of thermal history metrics for coral reef management, initially released in July 2014. The metrics were derived from CRW's Version 3.1 CoralTemp daily global 5 km (1/20°) satellite SST data product [https://coralreefwatch.noaa.gov/product/5km/index_5km_sst.php], for the period 1985-2018.

Coral reef sites that have experienced fewer heat stress events may have natural protection from exposure to conditions conducive to bleaching (e.g., strong mixing, upwelling). However, corals at those sites may also be more sensitive to heat stress, resulting in higher impacts if a stress event does occur. Alternatively, sites that have been regularly exposed to heat stress can have a reduced sensitivity, and therefore lower impact from the stress.

Coral reefs are among the most biologically rich and productive ecosystems on earth and provide valuable ecosystem benefits to millions of people in coastal areas. They are, however, widely threatened by both local threats (such as overfishing, pollution, and direct physical damage) and the global threats of ocean warming and acidification. These have already caused widespread damage to most of the world’s coral reefs, resulting in reduced areas of living coral, increased algal cover, diminished species diversity, and lower fish abundance, as well as degraded economic and social benefits to many coastal communities.

Source: National Oceanic and Atmospheric Administration (NOAA)

Data and Resources

This dataset has no data

Additional Info

Field	Value
Source	https://app.mapx.org/static.html?views=MX-AZ13M-E8316-ZOKUW&zoomToViews=true#JAAc6
Author	UNEP/GRID-Geneva
Maintainer	UNEP/GRID-Geneva
Last Updated	December 7, 2022, 08:17 (UTC)
Created	December 7, 2022, 08:17 (UTC)
GUID	MX-AZ13M-E8316-ZOKUW
Issued	2022-03-10 16:56:16
Language	EN
Modified	2022-04-28 15:22:02
Publisher email	info@mapx.org
Publisher name	UNEP/GRID-Geneva
Theme	Web Map
data_type	geospatial
keywords_m49	WLD
projects_description	This project was set up in the frame of the implementation of the Cartagena Convention Secretariat’s 2020/2021 work plan and budget approved by the Sixteenth Meeting of the Contracting Parties to the Convention for the Protection and Development of the Marine Environment of the Wider Caribbean Region held from July 28-30, 2021
projects_id	MX-L2W-HWZ-RIC-LM1-Y0V
projects_title	Caribbean Sea and Wider Caribbean Region
range_end_at_year	2022
range_start_at_year	1985
source_abstract	This dataset shows the frequency and intensity of heat stress events. Heat stress events can be detected using sea surface temperature (SST), which is the water temperature close to the ocean's surface. A heat stress event occurs when the SST near coral reefs exceeds the historical baseline for that area. This dataset describes the average period between severe heat stress events, where the Daily Heating Week (DHW) value was greater than or equal to 8, from 1985-2018 at a 5 kilometer (km) resolution. Shows 0.0 if no such events occurred. Stress events are defined by applying Coral Reef Watch's Degree Heating Week (DHW) methodology [https://coralreefwatch.noaa.gov/satellite/education/tutorial/crw24_dhw_product.php] at coral reef-containing and adjacent satellite pixel locations worldwide. The DHW attempts to capture both the level of abnormal heating and its duration: 1 DHW is equivalent to 1 week of SST 1°C above the expected summertime maximum at a given location. The three thresholds for heat stress in this dataset correspond to occurrence (DHW>0), significant coral bleaching (DHW≥4), and widespread bleaching and significant mortality (DHW≥8). SST and its fluctuations are critical to ecosystem dynamics and health, as many marine organisms can thrive only within certain temperature ranges. In particular, research indicates that a coral reef’s “thermal history” is among the most important factors influencing its ability to withstand heat stress events. Accordingly, with support from the National Oceanic and Atmospheric Administration (NOAA) Coral Reef Conservation Program, Coral Reef Watch (CRW) [https://coralreef.noaa.gov/] developed a variety of thermal history metrics for coral reef management, initially released in July 2014. The metrics were derived from CRW's Version 3.1 CoralTemp daily global 5 km (1/20°) satellite SST data product [https://coralreefwatch.noaa.gov/product/5km/index_5km_sst.php], for the period 1985-2018. Coral reef sites that have experienced fewer heat stress events may have natural protection from exposure to conditions conducive to bleaching (e.g., strong mixing, upwelling). However, corals at those sites may also be more sensitive to heat stress, resulting in higher impacts if a stress event does occur. Alternatively, sites that have been regularly exposed to heat stress can have a reduced sensitivity, and therefore lower impact from the stress. Coral reefs are among the most biologically rich and productive ecosystems on earth and provide valuable ecosystem benefits to millions of people in coastal areas. They are, however, widely threatened by both local threats (such as overfishing, pollution, and direct physical damage) and the global threats of ocean warming and acidification. These have already caused widespread damage to most of the world’s coral reefs, resulting in reduced areas of living coral, increased algal cover, diminished species diversity, and lower fish abundance, as well as degraded economic and social benefits to many coastal communities. Source: National Oceanic and Atmospheric Administration (NOAA)
source_title	Time between Severe Heat Stress Events (NOAA, 2019)
spatial	WLD