Quote:Heat waves are hitting the deep ocean floor, with potentially catastrophic results
Heat waves are reaching the bottoms of Earth's oceans, and that could be a big problem for the creatures that live there.
Heatwaves bleach coral reefs and if protracted will kill the coral, but critters live on/near the bottom of the seas too!
Quote:It's long been known that spikes in surface water temperature can devastate an ocean's ecosystem. For example, from 2013 to 2016, the surface waters of the Pacific Ocean along the North American coastline warmed up in a phenomenon dubbed "the blob," which led to the deaths of 1 million seabirds because their main meal source (fish) had been severely impacted.
But something similar is percolating in deeper waters. . . .
"We're seeing [bottom] marine heat waves happening around Australia and in places like the Mediterranean and Tasmanian seas. This is not something that's unique to North America."
The ocean has absorbed approximately 90% of the excess heat from global warming. This has led to an increase of about 1.8 degrees Fahrenheit (1 degree Celsius) over the past 100 years, according to NASA. . . .scientists had no clear picture of how the ocean depths responded when surface temperatures spiked.
To understand how atmospheric temperature changes were affecting the ocean bottom, scientists used existing measurements to simulate atmospheric conditions and ocean currents to "fill in the blanks" for difficult-to-access seafloor ecosystems. These ecosystems are often populated by lobsters, scallops, flounder, cod, and other commercially fished creatures, according to the statement.
Still don’t have a good idea of how the deep heats up.
https://www.livescience.com/heat-waves-are-hitting-the-deep-ocean-floor-with-pot...Paper article is based on:
https://www.nature.com/articles/s41467-023-36567-0 Quote:Abstract
Recently, there has been substantial effort to understand the fundamental characteristics of warm ocean temperature extremes—known as marine heatwaves (MHWs). However, MHW research has primarily focused on the surface signature of these events. While surface MHWs (SMHW) can have dramatic impacts on marine ecosystems, extreme warming along the seafloor can also have significant biological outcomes. In this study, we use a high-resolution (~8 km) ocean reanalysis to broadly assess bottom marine heatwaves (BMHW) along the continental shelves of North America. We find that BMHW intensity and duration varies strongly with bottom depth, with typical intensities ranging from ~0.5 °C–3 °C. Further, BMHWs can be more intense and persist longer than SMHWs. While BMHWs and SMHWs often co-occur, BMHWs can also exist without a SMHW. Deeper regions in which the mixed layer does not typically reach the seafloor exhibit less synchronicity between BMHWs and SMHWs.