북적도해류역에서 관측된 PIES자료를 이용한 위성 해수면 관측자료 평가

Abstract

An array of 5 pressure-recording inverted echo sounders (PIESs) was deployed across the North Equatorial Current (NEC) in the Northwestern Pacific Equatorial (NPE) region for 2 years from June 2012 to May 2014. It was located along the AVISO satellite altimetry Jason-2 214 ground track. The PIES measures bottom pressure and round-trip acoustic travel time from the sea floor to the sea surface. The bottom pressure and travel time measurements are used to estimate the mass-loading and steric height variations in sea surface height anomaly (SSHA), respectively. To evaluate the satellite altimetry, PIES-derived SSHA are compared with two sets of AVISO SSHA products: alongtrack mono-mission and mapped multi-mission SSHAs. It is found out that PIES-derived SSHA agrees better with mapped SSHA than along-track SSHA. The correlations between mapped SSHA and PIES-derived SSHA are in the range of 0.78 to 0.87, and those between along-track SSHA and PIES-derived SSHA are in the range of 0.65 to 0.79. Relatively large SSHA differences (> 15 cm) are found at two crossover points between 214 and 253 and 214 and 075 ground tracks around the PIES deployment sites although their observation times differ only 1.53 and 5.42 days, respectively. Time series of mapped SSHA interpolated to crossover points show almost median of two along-trackSSHAs, which appears increase the relationship between PIES-derived SSHA and mapped SSHA by reducO satellite altimetry Jason-2 214 ground track. The PIES measures bottom pressure and round-trip acoustic travel time from the sea floor to the sea surface. The bottom pressure and travel time measurements are used to estimate the mass-loading and steric height variations in sea surface height anomaly (SSHA), respectively. To evaluate the satellite altimetry, PIES-derived SSHA are compared with two sets of AVISO SSHA products: alongtrack mono-mission and mapped multi-mission SSHAs. It is found out that PIES-derived SSHA agrees better with mapped SSHA than along-track SSHA. The correlations between mapped SSHA and PIES-derived SSHA are in the range of 0.78 to 0.87, and those between along-track SSHA and PIES-derived SSHA are in the range of 0.65 to 0.79. Relatively large SSHA differences (> 15 cm) are found at two crossover points between 214 and 253 and 214 and 075 ground tracks around the PIES deployment sites although their observation times differ only 1.53 and 5.42 days, respectively. Time series of mapped SSHA interpolated to crossover points show almost median of two along-trackSSHAs, which appears increase the relationship between PIES-derived SSHA and mapped SSHA by reduc