Researchers in the University of Hawaiʻi at Mānoa’s International Pacific Research Center report recent findings, including increased hurricanes for Hawaiʻi, from new models examining climate change factors.
More hurricanes likely for Hawaiʻi
Hawaiʻi will likely experience more hurricanes given a global atmospheric general circulation model’s prediction that continued global warming will shift the location of tropical cyclones from the western to the central Pacific.
The shift is related to changes in the background vertical wind shear and boundary layer divergence, writes Professor of Meteorology Tim Li in the Nov. 3, 2010 Geophysical Research Letters.
Cloud fields likely to thin over Pacific
Current global climate models inadequately factor in the properties of clouds, Assistant Researcher Axel Lauer writes in the Nov. 20, 2010 Journal of Climate.
Lauer and colleagues simulated key features of present-day cloud fields over the eastern Pacific Ocean and adjacent land areas, including the observed response of clouds to El Niño. Thinning clouds and reduced cloud cover were more pronounced in the IPRC model.
If representative, even the highest warming predictions could underestimate the impact of increased greenhouse gases in the atmosphere.
Threshold temperatures for convection rise
The threshold sea surface temperature for convection is rising at the same rate as that of the tropical oceans, Postdoctoral Fellow Nat Johnson writes in Nature Geoscience online Nov. 7, 2010.
Atmospheric convection—hurricanes and tropical ocean thunderstorms—tends to occur when sea surface temperature rises above a threshold. If the threshold rises, as projected by global climate models, then hurricanes and other forms of tropical convection will require warmer ocean surfaces for initiation over the next century.