Sea surface height and mixed layer depth responses to sea surface temperature in northwestern Pacific subtropical front zone from spring to summer
C. Qiu1,4, H. Kawamura2, H. Mao3, and J. Wu11Center for Coastal Ocean Science and Technology, School of Marine Sciences, Sun Yat-sen University, Guangzhou 510275, China 2Center for Atmospheric and Oceanic Studies, Graduate school of Science, Tohoku University, Japan 3State key Laboratory of Tropical Oceanography, South China Sea Institute of Oceanology, Chinese Academy Science, China 4Guangdong Provincial Key Laboratory of Marine Resources and Coastal Engineering, School of Marine Sciences, Sun Yat-sen University, Guangzhou, China
Received: 24 Dec 2014 – Accepted for review: 11 Jan 2015 – Discussion started: 21 Jan 2015
Abstract. Qiu et al. (2014) quantitatively examined the mechanisms of sea surface temperature front disappearance, finding that the formation of shallow mixed layer depth (MLD) is very important. In the present study, we further investigated variations of the sea level anomaly (SLA) and mixed layer depth (MLD) during the SST front weakening period, based on weekly satellite derived products. For the SLA, we examined the steric height component of SLA, using empirical orthogonal function (EOF) method and physical method. The seasonal variations of steric height from above two methods have the same pattern: peak value (~ 20 cm) occurs in July-August, and minimum value (~ −5 cm) occurs in February to March. Correlation between SLA and SST achieves 0.76 in cold zone and frontal zone, and it is 0.86 between steric component and SST. When SST becomes large, MLD decreases gradually. The linear relationship (y = −4.46 x +156.47) between MLD and SST could be used to estimate the MLD in the subtropical front zone.
Qiu, C., Kawamura, H., Mao, H., and Wu, J.: Sea surface height and mixed layer depth responses to sea surface temperature in northwestern Pacific subtropical front zone from spring to summer, Ocean Sci. Discuss., 12, 83-101, doi:10.5194/osd-12-83-2015, 2015.