Impact of Typhoons on the Western Pacific: Temporal and Horizontal Variability of SST Cooling Annual Report, 2020
Abstract
This project is now in the first half of the third year (the field phase) of the ITOP program. The long term goal is to understand how the spatial variation of ocean and hurricane parameters, e.g., upper ocean temperature gradient, initial mixed-layer depth, etc., contribute to hurricane-ocean interaction. With this understanding we should then be in position to make better forecasts of hurricane-ocean interaction, and especially of hurricane intensity (Emanuel et al., 2004). The phenomenon of direct interest is the cooling of SST caused by hurricanes and typhoons, by up to 2 to 5 deg C (Price et al., 1994; Sanford et al., 2007; Cornillon et al., 1987). This SST cooling is observed to vary temporally--disappearing in O(10) days (Price et al., 2008), and spatially. The most impressive spatial variation of the cool wake seen behind moving hurricanes is that SST cooling is significantly biased to the right side of the hurricane track (looking in the direction of the hurricane motion) for translation speeds greater than about 2-3 m/sec. There is almost always observed to be a substantial variation of SST cooling in the direction parallel to a hurricane track as well. Factors that could cause along-track variation of cooling include spatial variation in the pre-hurricane oceanic temperature (and salinity) stratification, and of course spatial variation of the hurricane intensity and translation speed. This along-track variation of cooling has been a particular focus of this project, along with the wake warming. The objective of this project is to implement ocean models and diagnostics that are applicable to forecasting SST cooling, and after the fact, to help understand what factors contribute to hurricane/ocean interaction. One form of this developed in the previous year of this project is a depth-averaged temperature, T(sub 100), that is an estimate of the SST in a hurricane wake.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 28, 2010
- Accession Number
- ADA542475
Entities
People
- James F. Price
Organizations
- Woods Hole Oceanographic Institution