Image caption
Global map showing the highest category of marine heatwave an area of the ocean experienced in 2022, based on analysis of NOAA ocean temperature measurements (OISST). A marine heat wave is detected when surface temperatures are above the 90th percentile for five or more consecutive days. When the largest temperature anomaly (anomaly means "difference from average") during the event is less than double the 90th percentile for the seasonal anomaly, the heat wave is classified as moderate. When the temperature value is more than double, triple, or quadruple the 90th percentile for the seasonal anomaly, the MHW is categorized as strong, severe, or extreme, respectively. NOAA Climate.gov map, based on analysis and data from Robert Schlegel.