UNIVERSITY OF HAWAII IN MANOA
Using future projections from the latest generation of Earth System Models, a recent study published in Scientific advance found that most of the world’s oceans are slowly losing their memory year by year due to global warming.
Compared with the rapid weather fluctuations of the atmosphere, the slowly changing ocean exhibits strong persistence, or “memory”, which means tomorrow’s ocean temperatures could look like today, with only small changes. Therefore, ocean memory is often used to predict ocean conditions.
Oceanic memory decline is thought to be a general response across climate models to anthropogenic warming. As greenhouse gas concentrations continue to rise, such memory impairments will become increasingly apparent.
“We discovered this by examining the similarity of ocean surface temperatures from year to year as a simple metric for ocean memory,” said the statement. Hui Shi, lead author and researcher at the Farallon Institute in Petaluma, California. “It’s almost as if the ocean is developing amnesia.”
Oceanic memory was found to be related to the thickness of the ocean’s top layer, known as the mixed layer. The deeper composite layers have a greater heat content, creating more thermal inertia that is transferred to the memory. However, the mixed layer over most oceans will become shallower in response to continued anthropogenic warming, leading to ocean memory decline.
“Other processes, such as changes in ocean currents and changes in energy exchange between the atmosphere and oceans, also contribute to changes in ocean memory, but the coverage of mixed layer depth and leading to memory impairment occurring in all regions of the globe, said Robert Jnglin Wills, a research scientist at the University of Washington in Seattle, Washington, and a co-author of the study. , said.
Along with the decline in ocean memory, a thinning of the mixed layer was also found to increase random fluctuations in sea surface temperatures. As a result, although the ocean will not become more variable from year to year in the future, most of the signals useful for prediction will diminish.
“Decreased ocean memory coupled with increased stochastic volatility suggests intrinsic changes in the system and new challenges in prediction under warming,” said Fei-Fei Jinone atmospheric science professor at the University of Hawai’i at Mānoa School of Ocean and Earth Science and Technologyand co-author of the study.
Ocean amnesia not only affects the predictions of physical variables, but can also affect how we manage sensitive marine ecosystems.
“Decreased memory means less time to make predictions. This could hamper our ability to predict and prepare for ocean changes including marine heatwaves, which are known to cause dramatic and abrupt changes in ecosystems. oceans around the world,” said Michael Jacox, research scientist at NOAA’s Southwest Fisheries Science Center. Monterey, California, and co-author of the study.
In fisheries management, biological parameters used to assess stocks are estimated assuming a stable environment has been demonstrated in the recent past. Reduced ocean memory could render that estimate inaccurate and require new approaches to ecosystem-based fisheries management to include real-time ocean monitoring and other efforts. The decline in ocean memory can also have effects on populations of biological resources. Depending on whether species have adapted to more persistent or variable environmental conditions, future changes in their populations may be better estimated and predicted by looking at amnesia. in the ocean.
Besides ocean prediction, forecasting land-based effects on temperature, precipitation as well as extreme events can also be affected by oceanic memory deterioration due to their dependence on oceans. the stability of sea surface temperature as a predictable source. As the ocean’s memory continues to decline, researchers will likely have a hard time finding alternative predictors to ingenious predictions.
The study is a collaboration between scientists at:
● Farallon Institute
● University of Hawaii at Manoa
University of Washington
● NOAA Southwest Fisheries Science Center
● NOAA Physical Science Laboratory
University of Arizona
● NOAA’s Pacific Islands Fisheries Science Center
JOURNEYS
Scientific advance
DOI
RESEARCH METHODS
Data analysis / statistics
RESEARCH SUBJECTS
Do not apply
ARTICLE TITLE
Global ocean memory decline in the 21st century
ARTICLE PUBLICATION DATE
May 6, 2022
REPORT REPORT
Many authors claim that they have no interest in competing
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