Warmer Oceans Driving Stronger Currents, Bigger Storms

Super Typhoon Nepartak is no anomaly. Rising oceanic temperatures are intensifying major currents, which will result in hotter and stormier weather over the next century. The weather deterioration will predominantly occur along the eastern coastlines of Asia, Australasia, South Africa and South America.

This glum forecast comes from a team of climate scientists at the Alfred Wegener Institute (AWI) Helmholtz Centre for Polar and Marine Research in Bremerhaven, Germany. They analyzed oceanographic and satellite data from multiple databases and tested simulations of past and future climates, and presented their research results in the Journal of Geophysical Research: Oceans published by the American Geophysical Union (AGU).

The AWI team took particular interest in the western boundary currents (WBCs) running along the eastern coasts of Asia, Australasia, South Africa and South America. They include the Agulhas Current, the Brazil Current, the East Australian Current, the Kuroshio Current and the Gulf Stream.

These currents form at the western sides of ocean basins, hence the name. They drive warm water from tropical waters toward the poles.

According to the AGU blog, the AWI team found that all but one of the WBCs have been getting warmer and stronger as the CO2 level in the atmosphere has risen. The exception is the Gulf Stream, which is less subject to wind effects than the other WBCs.

The other currents are seeing an increase in temperature, building up heat that must eventually be released to the atmosphere. "The most common way to release the heat is storms," Hu Yang, one of the study authors, told Inside Climate News.

Yang also said that "China and Japan will suffer more warming than other regions." This suggests that yet more massive storms like Typhoon Nepartak will make landfall in those areas over the coming century. East Asia can expect warmer weather and greater precipitation in general, as well as greater storm frequency in wintertime, the scientist warns.