NOAA Coral Reef Watch (CRW) has been applying satellite remote sensing to monitor coral reef environments for more than a decade. CRW’s operational satellite sea surface temperature (SST)-based data products monitor global current coral reef environmental conditions to quickly identify areas at risk of thermally-induced mass coral bleaching. Mass coral bleaching events have been well correlated with thermal stress. In the event of severe thermal stress, disease and mortality may follow. Severe bleaching events have dramatic long-term ecological and social impacts. Continuous monitoring of bleaching-level thermal stress at the global scale provides coral reef managers, researchers and stakeholders with critical information to understand, predict, and monitor the development of mass coral bleaching. Taking advantage of continual improvement in NESDIS’ operational satellite SST products, CRW is now developing a next-generation near-real-time satellite decision support system. April 2013 NOAA Operational Satellite SST for Monitoring Coral Bleaching Thermal Stress: Coral Reef Watch’s Satellite Decision Support System for Coral Reef Managers Gang Liu, C. Mark Eakin, Jacqueline L. Rauenzahn, Scott F. Heron, Alan E. Strong, William Skirving, Jianke Li, Tim Burgess, Krystal Repoff, Kelly Howell, John Sapper NOAA Coral Reef Watch, E/RA3, NCWCP, 5830 University Research Court, College Park, MD USA The only satellite-based system available for U.S. and global coral reef management Early Warning System for Mass Coral Bleaching Events (Current system: 50-km, twice-weekly; Next-generation system: 5-km, daily) Bleaching Alert Area Degree Heating Weeks Sea Surface Temperature (SST) Coral Bleaching HotSpots SST Anomaly SST Trends (Map from ReefBase) (35S-35N) - Coral reefs thrive in global tropical regions: >18°C (35S-35N) -Cover less than 1% of the Earth’s surface -Provide habitat for 25% of all known marine species -Support approximately 500 million people -Require satellite remote sensing for global coverage, reaching remote areas, synoptic views of large areas, and real-time and/or near-real-time monitoring > 18ºC CRW Satellite Virtual Stations Annual Composites (Bleaching Alert Area) Increasing Bleaching Thermal Stress WorldPacificCaribbean % Reefs with Bleaching Stress Year 80 Bleaching Thermal Stress Based on Historical Pathfinder SST Data SST Time Week-0Week-12 SST Bleaching threshold (MMMSST+1ºC) Maximum of the Monthly Mean SST Climatology (MMMSST) bcad Hotspot Degree Heating Weeks CRW Satellite Bleaching Thermal Stress Monitoring Algorithms Stress Level Definition Potential Bleaching Intensity No Stress HotSpot ≤ 0No Bleaching Bleaching Watch 0 <HotSpot < 1 Bleaching Warning 1 ≤HotSpot and 0 < DHW < 4 Possible Bleaching Bleaching Alert Level 1 1 ≤HotSpot and 4 ≤ DHW < 8 Bleaching Likely Bleaching Alert Level 2 1 ≤HotSpot and 8 ≤ DHW Mortality Likely Bleaching Alert Area Degree Heating Weeks  ( HotSpot value  duration ) 12 weeks  1°C HotSpots : Instantaneous thermal stress Cumulative measure of thermal stress intensity and duration during the most-recent 12-week period ≥ 4 DHWs  Coral bleaching is expected ≥ 8 DHWs  Widespread bleaching and mortality are expected Coral Reef Watch: a NOAA/NESDIS program, funded predominantly by the NOAA Coral Reef Conservation Program (CRCP), integrates scientists from the Center for Satellite Applications and the Research (STAR) and Office of Satellite and Product Operations (OSPO).