Observational Evidence for Oceanic Controls on Hurricane Intensity
In a recent study published in Journal of Climate, Ian D. Lloyd of the Cooperative Institute for Climate Science - Princeton (CICS-P) and Gabriel A. Vecchi of the Geophysical Fluid Dynamics Laboratory (GFDL) analyzed observational data to examine the influence of upper oceanic conditions on hurricane intensity. The study finds that hurricanes can only achieve high intensities if they develop in regions where oceanic temperatures in the upper 250 meters (~800 feet) are favorable (with deep mixed layer and thermocline). The study provides evidence that one must account for subsurface oceanic conditions – in addition to atmospheric conditions – in order to make accurate projections and predictions of hurricane intensity.
Background: A long-term goal for the climate research community has been to improve our ability to predict the evolution of intense hurricanes. Traditionally, hurricane forecasts have focused on using atmospheric variables such as temperature, relative humidity, and vertical wind shear. However, modeling studies and in-situ observations have shown a prominent role for upper ocean thermal structure in limiting hurricane intensity. Ocean conditions affect hurricane intensity because vigorous ocean mixing caused by hurricanes brings cold water to the surface and can limit intensification through negative ocean feedback. The study shows that predictions of hurricane intensity can be improved by accounting for large-scale oceanic conditions.
Significance: Hurricane intensity projections under climate variability and change will be improved by accounting for large-scale ocean conditions, in addition to atmospheric factors. Furthermore, to improve the representation of hurricanes in high-resolution global climate models it will be necessary to include coupled interactions between the ocean and atmosphere. This research supports NOAA Mission Goal #2: Understand Climate Variability and Change to Enhance Societ y’s Ability to Plan and Respond .
Lloyd, I. D., and G. A. Vecchi (2011), Observational evidence for oceanic controls on hurricane intensity, Journal of Climate, 24(4), doi:10.1175/2010JCLI3763.1.
Name: Ian D. Lloyd*
Tel: (609) 356-8304
*Ian Lloyd recently earned his Ph.D. in Atmospheric and Oceanic Sciences and has accepted a one-year Congressional Science Fellowship sponsored by AGU.