Effects of super typhoons on cyclonic ocean eddies in the western North Pacific: A satellite data‐based evaluation between 2000 and 2008

Abstract

A composite time series of the merged satellite altimeters sea surface height anomaly (SSHA) data and satellite-observed sea surface temperature (SST) data were used to identify eddies in the Western North Pacific Ocean (WNPO), where there were numbers of intense typhoons. This study systematically investigated 15 super typhoons during the period of 2000-2008 in the WNPO to study their impacts on the pre-typhoon ocean features, e.g., the cyclonic ocean eddy (COE) feature (closed contours of SSHA < 26 cm) and neutral condition (SSHA between 26 and 6 cm). Two new COEs are generated by two super typhoons, and 18 pre-existing COEs are intensified by 13 super typhoons. 5 of the 13 super typhoons each influenced two pre-exisiting COEs. Although the typhoon-induced maximum cooling centers had a right bias along the tracks due to wind conditions, pre-existing COEs also play a significant role in determining the strength and location of large SST cooling. Three possible factors (maximum wind speed, typhoon translation speed and the typhoon forcing time, T f ) are employed to explain the interactions. Above all, the changes of the COE geometric and physical parameters (e.g., effective radius, area, SST, SSHA, and eddy kinetic energy) were mostly related to the typhoon forcing time, T f . This is because T f is a parameter that is a combination of the typhoon's translation speed, intensity and size. Although the typhoons may significantly impact COEs, such samples were not commonly observed. Thus, the impact of typhoon on the strength of COEs is generally inefficient.

The responses of cyclonic and anticyclonic eddies to typhoon forcing: The vertical temperature‐salinity structure changes associated with the horizontal convergence/divergence

“…In the AEs, the outflow (red solid arrows) of warm and fresh water diverges at subsurface, while the inflow (red dashed arrows) of the water converges at subsurface in the CEs. Figure extended the previous schematic diagram of vertical structure responses in the CEs [e.g., Sun et al ., ].…”

“…In the WNPO region, only 2 (Lupit and Ketsana) of 11 typhoons (18%) had notable impacts on SST cooling and phytoplankton blooms in 2003 [ Lin , ]. In the period of 2000–2008, only about 10% of CEs were significantly influenced by super typhoons [ Sun et al ., ]. Although the typhoon characteristics (including intensity, translation speed, and size) [ Vincent et al ., ; Mei et al ., ; Lu et al ., ], typhoon forcing time [ Sun et al ., ], and ocean thermal stratification [ Walker et al ., ; Zheng et al ., ; Mei et al ., ] are important on oceanic responses.…”

Response of a Preexisting Cyclonic Ocean Eddy to a Typhoon

“…Due to the ubiquitous mesoscale processes in the upper ocean, the interaction 30 between typhoons and mesoscale oceanic features such as cyclonic ocean eddies (COEs) has 31 attracted considerable attention (e.g., Jaimes et al 2011;Sun et al 2014;Walker et al 2005;32 Zheng et al 2008;Zheng et al 2010). Due to the ubiquitous mesoscale processes in the upper ocean, the interaction 30 between typhoons and mesoscale oceanic features such as cyclonic ocean eddies (COEs) has 31 attracted considerable attention (e.g., Jaimes et al 2011;Sun et al 2014;Walker et al 2005;32 Zheng et al 2008;Zheng et al 2010).…”

“…Sun et al (2014) illustrated the effects of super typhoons on the 40 strength, spatial area, and kinetic energy of COEs. Sun et al (2014) illustrated the effects of super typhoons on the 40 strength, spatial area, and kinetic energy of COEs.…”

Impact of Major Typhoons in 2016 on Sea Surface Features in the Northwestern Pacific

“…A subcritical (slow-moving) situation was found to have facilitated SSC and mixed layer deepening due to the absence of inertial-gravity waves in the wake of the typhoon.Moreover, the interactions between typhoons and ocean mesoscale eddies were also emphasized. The SST inside pre-existing cyclonic (cold) eddies drops remarkably after the passage of a typhoon because cold deep water is easily raised due to uplifted thermocline and large current shear under the base of the mixed layer [10,[25][26][27][28][29][30][31][32][33]. A tremendous SSC of 10.8 • C was recorded when Typhoon Kai-Tak passed over the cyclonic West Luzon Eddy in 2000 [28].…”