Interannual variability of winter precipitation linked to upper ocean heat content off the east coast of Korea. (22nd November 2017)

• Record Type: Journal Article
• Authors: Park, JongJin; Nam, SungHyun
• Is Part Of: International journal of climatology. Volume 38(2018)Supplement 1
• Page Start: e1266
• Page End: e1273
• Publication Date: 2017-11-22
• Subjects: precipitation -- snowfall -- ocean heat content -- marine planetary boundary layer -- sea surface wind -- sea surface temperature -- east coast of Korea; Climatology -- Periodicals; Climat -- Périodiques; Climatologie -- Périodiques; 551.605
• DOI: 10.1002/joc.5354
• Languages: English
• ISSNs: 0899-8418

Abstract

ABSTRACT: We present a link between highly variable winter precipitation (e.g. occasional heavy snow) in the mountainous cities along the east coast of Korea and upper ocean heat content (OHC) in the western part of the East Sea (Japan Sea). After removing annual climatological cycle, OHC (as well as sea surface temperature, SST) variability coherent with the winter sea surface wind (SSW) is extracted using maximum covariance analysis (MCA). The first‐mode MCA pattern, explaining 68% of the total covariance, indicates that the stronger westerly (easterly) winter SSW links to larger (smaller) OHC in the upper 400 m or higher (lower) SST of the western part of the sea. Time series of the first‐mode MCA are comparable to winter precipitation variability at three local cities along the coast (Gangneung, Donghae, and Uljin) with significantly high correlation coefficients (0.84, 0.68, and 0.56, respectively). The links between OHC and SSW and between SSW and precipitation are discussed because zonal contrast of OHC drives zonal tilt of northerly monsoonal wind in winter by canonical turbulent momentum exchange within the marine planetary boundary layer (MPBL). The momentum exchange within the MPBL yields the interannual variability of SSW and thus, winter precipitation in the coastal cities. Abstract : Patterns of winter water temperature at the upper ocean off the Korean east coast for (a) warmer versus (c) colder water near the coast, which corresponds northwesterly versus northeasterly wind (thick blue arrows) and negative versus positive anomaly in winter precipitation (heavy snowfall with northeasterly wind). Vertical profiles of typical zonal wind above the sea surface having (b) high and (d) low temperature. Thick grey arrows denote winter monsoon for (b) strengthened westerly and (d) easterly sea surface wind.