Validation and Application of Altimetry-Derived Upper Ocean Thermal Structure in the Western North Pacific Ocean for Typhoon-Intensity Forecast

• Published in: IEEE transactions on geoscience and remote sensing Vol. 45; no. 6; pp. 1616 - 1630
• Main Authors: Pun, I.-F., Lin, I.-I., Chau-Ron Wu, Dong-Shan Ko, Liu, W.T.
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.06.2007; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Altimetry; Amplification; Categories; Cooling; Covering; Hydrodynamics; Laboratories; Marine; Mathematical models; Meteorology; Ocean temperature; Oceans; Pacific Ocean; Predictive models; Regional; Space technology; Tropical cyclones; typhoon; Typhoons; upper ocean thermal structure; Wind forecasting; USA; IN, North Pacific
• ISSN: 0196-2892; 1558-0644
• DOI: 10.1109/TGRS.2007.895950

This paper uses more than 5000 colocated and near-coincident in-situ profiles from the National Oceanic and Atmospheric Administration/Global Temperature and Salinity Profile Program database spanning over the period from 2002 to 2005 to systematically validate the satellite-altimetry-derived upper ocean thermal structure in the western North Pacific ocean as such ocean thermal structure information is critical in typhoon-intensity change. It is found that this satellite-derived information is applicable in the central and the southwestern North Pacific (covering 122-170degE, 9-25degN) but not in the northern part (130-170degE, 25-40degN). However, since > 80% of the typhoons are found to intensify in the central and southern part, this regional dependence should not pose a serious constraint in studying typhoon intensification. Further comparison with the U.S. Naval Research Laboratory's North Pacific Ocean Nowcast/Forecast System (NPACNFS) hydrodynamic ocean model shows similar regional applicability, but NPACNFS is found to have a general underestimation in the upper ocean thermal structure and causes a large underestimation of the tropical cyclone heat potential (TCHP) by up to 60 kJ/cm 2 . After validation, the derived upper ocean thermal profiles are used to study the intensity change of supertyphoon Dianmu (2004). It is found that two upper ocean parameters, i.e., a typhoon's self-induced cooling and the during-typhoon TCHP, are the most sensitive parameters (with R 2 ~0.7) to the 6-h intensity change of Dianmu during the study period covering Dianmu's rapid intensification to category 5 and its subsequent decay to category 4. This paper suggests the usefulness of satellite-based upper ocean thermal information in future research and operation that is related to typhoon-intensity change in the western North Pacific