Climate models project an increase of more than 1 degree centigrade in global average surface temperatures by the middle of the century. However, actual change in ocean surface temperatures will vary by region, according to a team of scientists headed by meteorologist Shang-Ping Xie at the University of Hawaiʻi at Mānoa’s International Pacific Research Center.
That could cause significant changes in rainfall patterns in the tropics and subtropics, the scientists write in the February Journal of Climate.
They analyzed warming projections in models used by the Intergovernmental Panel on Climate Change, and two patterns stood out.
- In the Pacific, a temperature maximum emerges as a broad band across the equator. By changing atmospheric heating along the equator, this warming pattern sustains a rainband similar to that during El Niño, influencing climate around the world through large-scale, long-term atmospheric teleconnections.
- In the Indian Ocean, a pattern emerges during part of the year that is like the Indian Ocean Dipole, which occurs every decade or so today. The resulting dramatic shift in rainfall would bring droughts to Indonesia and Australia and increased rainfall in India and regions of Africa bordering the Arabian Sea.