Since the beginning of the 21st century, the rate of global warming has slowed despite rising greenhouse gas levels and increasing net radiation at the top of the atmosphere. A paper resulting from research funded by the Climate Program Office’s Modeling, Analysis, Predictions, and Projections program as well as the Climate Observation Division, published in Nature Geoscience on May 18th, provides a possible answer to the question of where the missing heat went.
Solving this mystery is essential for understanding the planet’s energy balance and implications on weather and climate predictions and long-term projections.
Previous studies suggested that persistent La Nina-like conditions with cold sea surface temperatures (SST) in the eastern tropical Pacific over the last decade caused wind and ocean currents to transport heat from the atmosphere into the Pacific Ocean.
However, this new research by Dr. Sang-Ki Lee at the University of Miami and NOAA AOML and other collaborators indicates that the ocean heat content in the upper 700m of the Pacific Ocean actually decreased from 2003-2012, even though the heat flux from the atmosphere into the Pacific increased during this time period.
They found that heat transported through the Indonesian throughflow from the Pacific Ocean to the Indian Ocean increased dramatically during the past decade, causing the Indian Ocean to soak up over 70% of Earth’s ocean heat gain in the upper 700m.
View the Nature Geosciences paper: www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo2438.html
Learn more at Nature News: www.nature.com/news/indian-ocean-may-be-key-to-global-warming-hiatus-1.17505?WT.ec_id=NEWS-20150521
Sang-Ki Lee, Wonsun Park, Molly O. Baringer, Arnold L. Gordon, Bruce Huber and Yanyun Liu. Pacific origin of the abrupt increase in Indian Ocean heat content during the warming hiatus. Nature Geoscience 8, 445-449 (2015).