Flat projection rectangular (Atlantic-centered), with grid lines showing Sea Surface Salinity measurements by Aquarius spacecraft between September 2011 & September 2014. Credit: NASA Scientific Visualization Studio
In collaboration with Princeton University scientists, a new study by scientists from the University of Miami's Rosenstiel School of Marine and Atmospheric Science has shown that global warming is being slowed down by increased ocean heat uptake.
A warming climate causes the global water cycle to become more intense. This means that wet areas are becoming wetter, and dry areas are becoming drier. Researchers found that ocean salinity also increased with the intensification of the climate. An increase in ocean salinity in salty areas, such as subtropical oceans leads to denser ocean water and greater heat uptake into the deep ocean. An increase in ocean heat uptake would decrease the rate at which the surface is warming.
Maofeng Liu is a postdoctoral researcher at UM Rosenstiel School and Department of Atmospheric Sciences. "We found a new mechanism that affects the rate of global warming via a suite of climate modeling experiments," said Maofeng Liu. The good match between climate model simulations, and observations over the past decade suggests that ocean heat uptake is likely to be enhanced by salinity changes caused by human-induced warming.
The researchers used a global climate modeling model to run two sets of experiments in order to carry out the study. They used the baseline set of experiments to increase the atmospheric carbon dioxide concentration by one percent each year, until it doubled. They repeated the first experiment, but did not allow the global hydrological cycle to change due to surface salinity. Both sets of experiments produced different results, which highlights the effects of water cycle changes on ocean heat uptake and transient temperature change.
Video projection (Atlantic-centered), with grid lines showing Sea Surface Salinity measurements by Aquarius spacecraft between September 2011 & September 2014. Credit: NASA Scientific Visualization Studio
Global warming is caused by the release of greenhouse gases into the atmosphere. This causes sea level to rise and can lead to more severe storms, droughts and wildfires.
Liu stated that "Predicting global warming's rate is still difficult." "This study revealed a new effect on the rate of global heating."
The study was published by Nature Climate Change.
Continue reading Does global warming have stopped? You cannot turn off the flow of energy.
More information: The enhanced hydrological cycle increases ocean heat intake and modifies transient climate change, Nature Climate Change (2021). www.nature.com/articles/s41558-021-01152-0 Journal information: Nature Climate Change Enhanced hydrological cycle increases ocean heat uptake and moderates transient climate change,(2021). DOI: 10.1038/s41558-021-01152-0
