Abstract
Long-term trends of sea surface temperature (SST) of the East Sea (Sea of Japan, EJS) were estimated by using 37-year-long satellite data, for the observation period from 1982 to 2018. Overall, the SST tended to increase with time, for all analyzed regions. However, the warming trend was steeper in the earlier decades since the 1980s and slowed down during the recent two decades. Based on the analysis of the occurrence of events with extreme SST (high in the summertime and low in the wintertime), a shift toward the more frequent occurrence of events with extremely high SST and the less frequent occurrence of events with extremely low SST has been observed. This supports the observations of the consistent warming of the EJS. However, seasonal trends revealed continuous SST warming in the summertime, but frequent extreme SST cooling in the wintertime, in recent decades. The observed reduction in the warming rates occurred more frequently in specific regions of the EJS, where the occurrence frequency of events with extremely low SST was unusually high in the recent decade. The recent tendency toward the SST cooling was distinctively connected with variations in the Arctic Oscillation index. This suggests that changes in the Arctic Ocean environment likely affect the recently observed SST changes in the EJS, as one of the marginal seas in the mid-latitude region far from the polar region.
Highlights
Sea water temperature of the global ocean has been increasing significantly over the past decades
Going from the southern part of the EJS to its northern part, the mean sea surface temperature (SST) variation decreases from ~20 ◦C in the Korea Strait to ~5 ◦C in the Tatar Strait, with relatively concentrated SST differences along the subpolar front (SPF) along the zonal line of about 40◦N [39]
The present study showed long-term SST warming trends in almost all of the EJS regions, during the 37-year-long observation period, from 1982 to 2018
Summary
Sea water temperature of the global ocean has been increasing significantly over the past decades. The rate of the temperature increase in the upper ocean layer (within 75 m of the ocean surface) was reported as 0.11 ◦C decade−1, for the observation period from 1971 to 2010 [1]. Since the 1970s, as the ocean observations were recorded regularly, data on the mean temperature change in the global ocean have been available [2,3]. In addition to in-situ temperature measurements, satellite observations of the ocean allow to monitor and understand long-term changes in the sea surface temperature (SST) of the global ocean. Some studies reported a slowdown in the global ocean’s SST warming rate during recent decades [1,12,13]. The occurrence of events with extremely high temperature has been increasing, yielding surface warming [14]. Tmhueltoi-bdjeecctaivdeasl soaftethlliistestduadtay. are 1) to estiTmhaetreetfhoeref,uinndthamis esntutadlyv, awreiaetixoanmsiannedd dloenrigv-etetrhme tSrSeTndtreinndthsealnodngre-tceernmt tSreSnTdinchthanegEeJsSionvtehretEhJeS, 3w7-hyeicahr-alorengveorbyseimrvpaotirotnanptetroiotdh,efcrloimma1t9e8o2fttohe20K1o8;re2a)ntopiennviensstuiglaa.teTahneyotbejnecdteivnecsyoofftthhies SstSuTdtyreanrdes1) btyo aepstpimlyaintegthae2f0u-nydeaarm-wenidtael vslaidriiantgionwsinanddowdetroivtehtehetotrtaelndSSinT tdhaetlaobnags-etetromilSluSTstrinattehea EsJiSgnoivfiecranthte in3c7r-eyaesaer-lionntghoebosecrcvuartrieonncepeorifoSdS, Tfrocmoo1li9n8g2 teov2e0n1ts; i2n) troecinenvtesdtiegcaatdeeasn,yatnedndreenvceyalofsptheeciSfiScTstereansodnsably vaapripaltyioinngs ain2t0h-yeeSaSrT-wtridenedslsidfoincguswedinodnowthteoStShTe ctootoallinSgST; 3d) atotaubansceotvoerillaunsytrraetleaatiosingnoiffitchaenSt SinTcrtreeansedsin totheextorcecmurerlyenhcoetoofrScSoTldcoevoelinntgs;eavnednt4s)itnoreexcaemntindeecthadeerse,laatniodnrsehviepabl estpweceiefinctsheeassloonwaldvoawrinatoifotnhseinSStThe inScSrTeatsreenrdastefoacnudsethdeoAnrtchteicSOSTscciloloatliinogn;(3A) Oto),uunscionvgetrhaenwy arevlealteitoncoohfetrheenScySTantraelnydsiss.to extremely hot or cold events; and 4) to examine the relationship between the slowdown of the SST increase rate and the Arctic Oscillation (AO), using the wavelet coherency analysis
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
