Formation and Distribution of Low Salinity Water in East Sea Observed from the Aquarius Satellite

(1)

한수지 51(2), 187-198, 2018

187 Korean J Fish Aquat Sci 51(2),187-198,2018

Original Article

서 론

동해에서는매년가을염분

32.5 psu

이하의저염수가관측된 다

(Lee and Lee, 2017).

동중국해에서대한해협을통해유입되 는저염수와동해북부에서해빙에의해형성된저염수가그기 원으로알려져있다

. 6

월

- 7

월에중국의양자강에서동중국해 로유입되는담수와해수가섞여제주도서쪽해상에형성된장 강희석수

(Changjiang diluted water)

는

7

월

-8

월에대한해협방 향으로확산하며그확산범위는

8

월에동중국해에서부는남 풍의강도에따라변동한다

(Lee et al., 2015). Beardsley et al.

(1992)

은위성추적뜰개를이용하여장강희석수가

20 cm·s

^-1 정도의속도로

9

^월에^대한해협^서수도를^통과하여^동해로^유입 되는것을관측하였다

(Fig. 1). Bai et al. (2014)

은

Aquarius

염 분관측위성자료를이용하여동중국해에서의동남계절풍이 장강희석수의동해쪽으로의확산세력을결정한다고연구하였 다

.

겨울철에타타르해협근해와블라디보스톡연안해역이결 빙되고

,

^봄철에는^이^해빙이^녹아^{결빙되었던}^해역^근해에^저염

수가형성된다

(Park et al., 2014).

^해빙이^녹은^해수에^의해^밀 도가낮은물이시베리아연안을따라형성되고외해와의밀도

차이로인해연안을따라남향하는리만해류

(Liman Current)

가늦은봄에형성된다

(Martin and Kawase, 1998; Park et al., 2014).

리만해류는여름까지흐름이계속되며북한한류

(North Korean Cold Current)

^와^합류하여

(Byun and Seung, 1984)

^울 릉도근해까지남하하는것으로알려졌다

(Lee and Lee, 2017)

(Fig. 1).

그러나리만해류가여름철까지계속남하하여북한한

류와합류하는지에대한여부는아직잘연구되지않았다

.

북한 한류에대하여

An (1974)

과

Kim and Kim (1983)

의연구는있 었으나

,

^북한^{해역에서의}^해양^관측이^어려워^최근에^들어서야 동해북부해상기원저염수에대한연구가시작되었다

(Park et al., 2016; Lee and Lee, 2017).

Lee and Niiler (2010)

는위성추적뜰개를이용한표층해류

연구에서대한해협서수도를통과하는해수는동한난류

(Fig.

1, East Korean Warm Current)

^를^따라^북상하다^울릉^분지로 진입하며

,

동수도를통과한해수는오키뱅크

(Oki Bank)

나노

Aquarius 염분 관측 위성에 의한 동해 저염수의 형성과 유동 연구

이동규*

부산대학교 자연과학대학 해양학과

Formation and Distribution of Low Salinity Water in East Sea Observed from the Aquarius Satellite

Dong-Kyu Lee*

Department of Oceanography, College of Natural Science, Pusan National University, Busan 46241, Korea

The monthly salinity maps from Aquarius satellite covering the entire East Sea were produced to analyze the low-sa- linity water appearing in fall every year. The low-salinity water in the northern East Sea began to appear in May-June, spreading southward along the coast and eastward north of the subpolar front. Low-salinity water from the East China Sea entered the East Sea through the Korea Strait from July to September and was mixed with low-salinity water from the northern East Sea in the Ulleung Basin. The strength of the low-salinity water from the East China Sea was depen- dent on the strength of the southerly wind of the East China Sea in July-August. The salinity reaches a minimum in September with a distribution parallel to the latitude of 37.5°N. In October, low salinity water is distributed along the mean current path and subpolar front and the entire East Sea is covered with the low salinity water in November.

Water with salinity larger than 34 psu starts to flow into the East Sea through the Korea Strait in December and it expands gradually northward up to the subpolar front in January- February.

Key words: Aquarius, Low salinity water, East Sea, Changjiang Diluted Water

This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial Licens (http://creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

https://doi.org/10.5657/KFAS.2018.0187

Korean J Fish Aquat Sci 51(2) 187-198, April 2018

Received 26 March 2018; Revised 7 April 2018; Accepted 10 April 2018

*Corresponding author: Tel: +82. 51. 510. 2270 Fax: +82. 51. 581. 2963

E-mail address: [email protected]

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188

이동규

토반도

(Noto Peninsula)

^를^따라^북상하여^{울릉분지에서}^북동 진하는동해해류

(Fig. 1, East Sea Current)

와합류한다고하였 다

.

또한북한한류는여름철에만강릉연안까지남하하는것으 로관측되었다

(Lee and Niiler, 2005). Park et al. (2016)

은동해 중부연안의장기해류관측으로부터동해북부연안해역에서 봄에형성된저염수가여름철에동해북부연안을따라남하하 는것으로확인하였다

. Lee and Lee (2017)

에의하면매년북한 한류에의해남하한저염수는울릉분지에서대한해협으로유 입된저염수와만나섞인다

.

이와같이동해에서는동중국해에 서기원한고온

-

저염의장강희석수와동해북부해상에서기원 한저온

-

^저염의^동해^북부^저염수가^가을철^동해^남서부^해상에 서섞여남부해역전체의표층에저염수가분포하게되는

,

전 세계의다른해역에서찾아보기힘든독특한현상이일어난다

.

지정학적이유로동해전역에걸친해수특성관측이어려워 동해저염수의유동에대한시공간적특성은잘연구되고있지

않다

.

^그러나

2011

^년

9

^월부터

2015

^년

5

^월까지^{인공위성을}^이 용한염분관측프로그램

(Aquarius)

이진행되었다

. Aquarius

염분관측미션의목표는위경도

1°×1°

의격자에서월별평균

한관측값이

0.2 psu

이내의정확도를갖는것이다

.

그러나

Lee

(2016)

는동해를둘러쌓고있는육지및위성이대륙에서바

다로비행할경우발생하는주파수간섭

,

^그리고^겨울철^해표

면수온이낮은관계로인해

1 psu

이상의큰구조적오차가나

타나는것을발견하여

CTD (conductivity-temperature-depth), Argo

뜰개등에의한관측자료와

HYbrid Coordinate Ocean

Model (HYCOM)

재분석자료를이용한보정기법을개발하

였다

.

^본^{논문에서는}

aquarius

^염분^관측^{프로그램의}^미션^최종 자료

(version 5)

를

Lee (2016)

에의해개발된보정기법을적용

Fig. 1. The schematics of mean surface circulation in the Japan/

East Sea [redrawn from Lee et al., (2016)]. The solid box near Changjiang indicates the area for wind calculation shown in Fig.

5. Changjiang diluted water (CDW), East Korean warm current (EKWC) and North Korean cold current (NKCC) are marked on the map.

129°E 132°E 135°E 138°E 141°E

44°N

42°N

40°N

38°N

36°N

20 15 10 5 10 -5 -10 -15 -20

44°N

42°N

40°N

38°N

36°N

20 15 10 5 10 -5 -10 -15 -20

2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 Year

-2 6 5 4 3 2 1 0 -1 7

Northward Wind Speed (m/s)

8

2012/01 2013/01 2014/01 2015/01

700 600 500 400 300 200 100 0

Number of Ice Pixel Air Temperature off Vladivostok (℃)

-5 -6 -7 -8 -9 -10 -11 -12

129°E 132°E 135°E 138°E 141°E

44°N

42°N

40°N

38°N

36°N

35 34.5 34 33.5 33 32.5 32 JulyAugust

Ice Area Air Tem

44°N 40°N

36°N

130°E 135°E 140°E 5 4 3 2 1

0 130°E 135°E 140°E 5 4 3 2 1 0 30°

35°

40°

45 50°

55°

30°

35°

40°

45 50°

55°

120° 125° 130° 135° 140° 145°

1 10 17

1 3 7 8

0 2 2 2 6

1

3 0

(b) Bias×0.01 5

20 20 14 13 23 40 40 23 15 13 13 18 25 36

2 13 13 12 14 17 19 19 16 13 14 11 11 13 13 14 14 14 16 15

12 13 13 12 12 15 18 10 9 12 13 14 12 11 12 12 13 12 16

7 6 6 10 10 10 8 9 8

9 9 9 6

(a) Bias×0.1

N

J

33

33 33.5

33.5

33.5 33.5

33.3 33.3

33 33.3

33.3 CDW

NKCC

Changjiang

Subpolar Front East Sea Current

Noto Peninsular Oki Bank

Liman Current Tatar Strait

Vladivostok

?

EKWC

Jan Feb

Fig. 2. Biases (a) between HYCOM (hybrid coordinate ocean model) salinity regressed with observation and aquarius salinity, and (b) between HYCOM salinity regressed with observation and corrected aquarius salinity. The red boxes indicate the areas of comparison between the corrected aquarius salinity and the salinity observed with the conductivity-temperature-depth.

129°E 132°E 135°E 138°E 141°E

44°N

42°N

40°N

38°N

36°N

20 15 10 5 10 -5 -10 -15 -20

44°N

42°N

40°N

38°N

36°N

20 15 10 5 10 -5 -10 -15 -20

2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 Year

-2 6 5 4 3 2 1 0 -1 7

8

2012/01 2013/01 2014/01 2015/01

700 600 500 400 300 200 100 0

-5 -6 -7 -8 -9 -10 -11 -12

129°E 132°E 135°E 138°E 141°E

44°N

42°N

40°N

38°N

36°N

35 34.5 34 33.5 33 32.5 32 JulyAugust

Ice Area Air Tem

44°N

40°N

36°N

130°E 135°E 140°E 5 4 3 2 1

0 130°E 135°E 140°E 5 4 3 2 1 0 30°

35°

40°

45 50°

55°

30°

35°

40°

45 50°

55°

120° 125° 130° 135° 140° 145°

1 10 17

1 3 7 8

0 2 2 2 6

1

3 0

(b) Bias×0.01 5

20 20 14 13 23 40 40 23 15 13 13 18 25 36

2 13 13 12 14 17 19 19 16 13 14 11 11 13 13 14 14 14 16 15

12 13 13 12 12 15 18 10 9 12 13 14 12 11 12 12 13 12 16

7 6 6 10 10

10 8 9 8

9 9 9 6

(a) Bias×0.1

N

J

33

33 33.5

33.5

33.5 33.5

33.3 33.3

33 33.3

33.3 CDW

NKCC

Changjiang

Vladivostok

?

EKWC

^자료와^실측^된^염분^자료와^비교하여

33.5 psu

^이하 의

HYCOM

염분은

(S

_H

-32)×2.3446+29.983

의관계식을이

용하여수정하여사용하고

33.5 psu

이상의

HYCOM

염분은

수정없이사용하였다

.

내려받은

aquarius

염분과수정된월별

평균

HYCOM

염분자료를

1°×1°

격자에서비교하여격자별

평균바이어스값을계산하여

Aquarius

^염분을^격자^별로^수정

하였다

.

겨울철

(12

월

-3

월

)

에는해표면수온이아주낮고강한

바람에의해해표면거침도

(roughness)

가커평균바이어스가

다른계절에비해크게다른것으로나타나겨울철에만적용하 는바이어스값을구하여사용하였다

.

또한어떤격자는상승

(ascending,

^동해에서^아시아^대륙^방향으로^진행하는

)

^궤도^만

의자료

(SCIA)

를이용한염분이상승

-

하강궤도의모든자료를

사용한자료

(SCI)

보다평균바이어스가작아

SCIA

, 4

월의

aquarius

관측염

분이실측염분에비해오차가

0.5 psu

.

Fig. 3. Box mean salinity observed with conductivity-temperature-depth with 95% confidence interval (black squares with bar), corrected V4.0 aquarius salinity (black triangles) and corrected V5.0 aquarius salinity (gray circles) in (a) box N and (b) box J shown in Fig. 2. NIFS, national institute of fisheries science; JMA, Japan meteorological agency.

11-10 12-01 12-04 12-07 12-10 13-01 13-04 13-07 13-10 14-01 14-04 14-07 14-10 15-01 15-04

11-10 12-01 12-04 12-07 12-10 13-01 13-04 13-07 13-10 14-01 14-04 35

34 33 32 31 35 34 33 32 31 (a)

(b)

130°E 135°E 140°E 130°E 135°E 140°E 130°E 135°E 140°E 130°E 135°E 140°E

32 33 34 35 32 33 34 35 32 33 34 35 32 33 34 35

44°N

40°N

36°N

32 33 34 35 32 33 34 35 32 33 34 35 32 33 34 35

44°N

40°N

36°N

32 33 34 35 32 33 34 35 32 33 34 35 32 33 34 35

44°N

40°N

36°N

32 33 34 35 32 33 34 35 32 33 34 35 32 33 34 35

44°N

40°N

36°N

130°E 135°E 140°E 130°E 135°E 140°E 130°E 135°E 140°E 130°E 135°E 140°E

32 33 34 35 32 33 34 35 32 33 34 35 32 33 34 35

44°N

40°N

36°N

32 33 34 35 32 33 34 35 32 33 34 35 32 33 34 35

44°N

40°N

36°N

32 33 34 35 32 33 34 35 32 33 34 35 32 33 34 35

44°N

40°N

36°N

32 33 34 35 32 33 34 35 32 33 34 35 32 33 34 35

44°N

40°N

36°N

130°E 135°E 140°E 130°E 135°E 140°E 130°E 135°E 140°E

32 33 34 35 32 33 34 35 32 33 34 35 32 33 34 35

44°N

40°N

36°N

32 33 34 35 32 33 34 35 32 33 34 35

44°N

40°N

36°N

32 33 34 35 32 33 34 35 32 33 34 35

44°N

40°N

36°N

32 33 34 35 32 33 34 35 32 33 34 35

44°N

40°N

36°N

34

34 34

34 May. 2012

34 34 34

34.5 34.5 Jun. 2012

34 34

34

34.5 Jul. 2012

33.5 34 Aug. 2012 34

33.5 34

34 34

34 34.5 May. 2013

34 34

34.5 34

Jun. 2013

34 34 34Jul. 2013

33

33 33.5

33.5 34 34Aug. 2013

34 34

34 34 34

34 34.5 May. 2014

34

34 3434 Jun. 2014

34

34.5 34.5 Jul. 2014

33.345 3434.5 Aug. 2014

3334.5 33.5

34 34

34

May. 2015

33.5 33.5

34

34 34

34 3434

34.5 Jan. 2012 34.5

33.5 33.5 34

34 34 34Feb. 2012

33.5 34

34 34

343 34 4.5 Mar. 2012

33.5 34

34 34 34.5

34.5 34.5 Apr. 2012

33.5 33.5

33.5 33.5 34

34

34 Jan. 2013

33.5 33.5

34

34.5 Feb. 2013

33

34

34 34 34.5

34.535 Mar. 2013

34

3434.5

34.5

35 35 Apr. 2013

33.5 34

34

34 34

34

34.5 Jan. 2014

34

34 34 Feb. 2014

34

34 34

34.5 34.5

34.5 34.5 35

Mar. 2014

34 34.5

34.5 34.5 3535

35 Apr. 2014

5.33

34

34 43

34

34.5 Jan. 2015

33.5

43 34

34 34 34

34 34.5

34.5 Feb. 2015

33.5 33.5

33.5

34 34 34

34.534.5

5.43

Mar. 2015

34 34

34.5 35 Apr. 2015

Jan. 30, 2012 Jan. 30, 2015

33

33.5 33.534 Sep. 2011

33 33

33

33 33

33.5 Oct. 2011

33 33

33 33.5

33.5 Nov. 2011

33.5

34 34

34 3434.5 Dec. 2011

33

33.5 33.5 34 Sep. 2012

33 33 33.5

33.5 Oct. 2012

33

33 33

33 33.5 Nov. 2012

33 33

33 33.5

33.5

34 34 Dec. 2012 34

3232.53333.5 34Sep. 2013

32.5 33

33

3333.5

Oct. 2013

32.5

33 33

3333 33

33.5 Nov. 2013 34

34 34 34

34 34

34.5 Dec. 2013

33

33 33.5 33.5

34

Sep. 2014 34

33 33.5 33.5

3433.5

34 Oct. 2014

33

33 33

33.534 Nov. 2014

34

34 34

^월별

4

^년^{평균으로는}^{동해에서의}^평균 적인저염수분포를논의하기에부족할수있어본논문에서 는

World Ocean Atlas 2005-2012

의월평균염분분포

(www.

nodc.noaa.gov/OC5/woa13)

와도비교 논의 하였다

.

기온 자 료는

6

시간간격

European center for medium-range weather forecasts (ECMWF)

^의

ERA-interim

^재분석^기온^자료를^사용 하였고

national snow and ice data centre (nsidc.org/data)

에서 해빙분포자료를내려받아겨울철동해북부해상의해빙의 크기와봄철동해북부의저염수형성과의상관관계를분석하 였다

.

결 과

동해 저염수의 형성 및 연 변동 동중국해 기원 저염수

저염수형성과정및연변동을보기위해

5

월

-8

월의월별염 Table 1. Seasonal biases used for correcting Aquarius salinity. In

the transitional month of April, the midpoint of the biases of the two seasons is used for correction

Longitude Latitude Bias

(May-Nov) Dataset Bias

(Dec-Mar) Dataset

129.5 36.5 0.68 SCI 3.85 SCI

130.5 36.5 0.59 SCI 3.81 SCI

131.5 36.5 0.76 SCI 2.35 SCI

132.5 36.5 0.64 SCI 1.93 SCI

133.5 36.5 1.45 SCI 3.10 SCI

134.5 36.5 2.85 SCI

135.5 36.5 2.86 SCI

131.5 37.5 0.74 SCI 2.63 SCI

132.5 37.5 0.79 SCI 2.11 SCI

133.5 37.5 0.85 SCI 2.06 SCI

134.5 37.5 1.16 SCI 2.64 SCI

135.5 37.5 1.74 SCI 3.47 SCI

136.5 37.5 2.61 SCI 4.63 SCI

130.5 38.5 0.76 SCI 2.37 SCI

131.5 38.5 0.91 SCI 2.36 SCI

132.5 38.5 1.18 SCI 2.00 SCI

133.5 38.5 1.12 SCI 2.22 SCI

134.5 38.5 1.09 SCI 2.49 SCI

135.5 38.5 1.17 SCI 2.72 SCI

136.5 38.5 1.35 SCI 2.70 SCI

137.5 38.5 0.96 SCI 2.32 SCI

138.5 38.5 0.61 SCI 2.08 SCI

139.5 38.5 0.85 SCI 2.21 SCI

140.5 38.5 2.16 SCI

130.5 39.5 0.62 SCIA 1.86 SCIA

131.5 39.5 0.58 SCIA 1.55 SCIA

132.5 39.5 0.44 SCIA 1.47 SCIA

133.5 39.5 0.71 SCIA 1.81 SCIA

134.5 39.5 0.71 SCIA 1.81 SCIA

135.5 39.5 0.97 SCI 2.16 SCI

136.5 39.5 1.00 SCI 2.21 SCI

137.5 39.5 1.10 SCI 2.42 SCI

138.5 39.5 1.08 SCI 2.36 SCI

132.5 40.5 0.47 SCIA 1.50 SCIA

133.5 40.5 0.54 SCIA 1.61 SCIA

134.5 40.5 0.61 SCIA 1.65 SCIA

135.5 40.5 0.81 SCIA 1.69 SCIA

136.5 40.5 0.79 SCIA 1.70 SCIA

137.5 40.5 1.01 SCIA 2.37 SCIA

138.5 40.5 1.09 SCI 2.83 SCI

Table 1. continued

Longitude Latitude Bias

(May-Nov) Dataset Bias

(Dec-Mar) Dataset

131.5 41.5 0.66 SCIA 2.61 SCIA

132.5 41.5 0.47 SCIA 2.15 SCIA

133.5 41.5 0.56 SCIA 2.16 SCIA

134.5 41.5 0.56 SCIA 1.83 SCIA

135.5 41.5 0.47 SCIA 1.54 SCIA

136.5 41.5 0.57 SCIA 1.69 SCIA

137.5 41.5 0.61 SCIA 1.69 SCIA

138.5 41.5 0.76 SCIA 2.16 SCIA

139.5 41.5 0.64 SCI 1.92 SCI

133.5 42.5 0.12 SCIA 1.53 SCIA

134.5 42.5 -0.09 SCIA 1.10 SCIA

135.5 42.5 0.02 SCIA 1.13 SCIA

136.5 42.5 0.23 SCIA 1.31 SCIA

137.5 42.5 0.34 SCIA 1.44 SCIA

135.5 43.5 -0.02 SCIA 1.40 SCIA

136.5 43.5 0.27 SCIA 1.26 SCIA

137.5 43.5 0.34 SCIA 1.27 SCIA

138.5 43.5 0.22 SCI 1.64 SCI

136.5 44.5 0.29 SCI 1.70 SCI

137.5 44.5 0.26 SCI 1.65 SCI

138.5 44.5 0.30 SCI 1.65 SCI

139.5 44.5 0.09 SCI 1.36 SCI

(5)

동해 저염수 유동

191

분분포를

Fig. 4

에도시하였다

.

동해남부는

5

월부터

2014

년 을제외하고

34 psu

이하의저염수가북위

37°

이남

(2013

년

5

8

월의동해남부의저염수분포는다른해에비해세력이아

주약하게나타났다

. 2013

년

7

월에는남풍이평년보다아주강

11-10 12-01 12-04 12-07 12-10 13-01 13-04 13-07 13-10 14-01 14-04 14-07 14-10 15-01 15-04

11-10 12-01 12-04 12-07 12-10 13-01 13-04 13-07 13-10 14-01 14-04 35

34 33 32 31 35 34 33 32 31 (a)

(b)

130°E 135°E 140°E 130°E 135°E 140°E 130°E 135°E 140°E 130°E 135°E 140°E

32 33 34 35 32 33 34 35 32 33 34 35 32 33 34 35

44°N

40°N

36°N

32 33 34 35 32 33 34 35 32 33 34 35 32 33 34 35

44°N

40°N

36°N

32 33 34 35 32 33 34 35 32 33 34 35 32 33 34 35

44°N

40°N

36°N

32 33 34 35 32 33 34 35 32 33 34 35 32 33 34 35

44°N

40°N

36°N

130°E 135°E 140°E 130°E 135°E 140°E 130°E 135°E 140°E 130°E 135°E 140°E

32 33 34 35 32 33 34 35 32 33 34 35 32 33 34 35

44°N

40°N

36°N

32 33 34 35 32 33 34 35 32 33 34 35 32 33 34 35

44°N

40°N

36°N

32 33 34 35 32 33 34 35 32 33 34 35 32 33 34 35

44°N

40°N

36°N

32 33 34 35 32 33 34 35 32 33 34 35 32 33 34 35

44°N

40°N

36°N

130°E 135°E 140°E 130°E 135°E 140°E 130°E 135°E 140°E

32 33 34 35 32 33 34 35 32 33 34 35 32 33 34 35

44°N

40°N

36°N

32 33 34 35 32 33 34 35 32 33 34 35

44°N

40°N

36°N

32 33 34 35 32 33 34 35 32 33 34 35

44°N

40°N

36°N

32 33 34 35 32 33 34 35 32 33 34 35

44°N

40°N

36°N

34

34 34

34 May. 2012

34 34 34

34.5 34.5 Jun. 2012

34 34

34

34.5 Jul. 2012

33.5 34 Aug. 2012 34

33.5 34

34 34

34 34.5 May. 2013

34 34

34.5 34

Jun. 2013

34 34

34

Jul. 2013

33

33 33.5

33.5 34 34Aug. 2013

34 34

34 34 34

34 34.5 May. 2014

34

34 3434 Jun. 2014

34

34.5 34.5 Jul. 2014

33.345 3434.5 Aug. 2014

3334.5 33.5

34 34

34

May. 2015

33.5 33.5

34

34 34

34 3434

34.5 Jan. 2012 34.5

33.5 33.5 34

34 34 34Feb. 2012

33.5 34

34 34

343 34 4.5 Mar. 2012

33.5 34

34 34 34.5

34.5 34.5 Apr. 2012

33.5 33.5

33.5 33.5 34

34

34 Jan. 2013

33.5 33.5

34

34.5 Feb. 2013

33

34

34 34 34.5

34.535 Mar. 2013

34

3434.5

34.5

35 35 Apr. 2013

33.5 34

34

34 34

34

34.5 Jan. 2014

34

34 34 Feb. 2014

34

34 34

34.5 34.5

34.5 34.5 35

Mar. 2014

34 34.5

34.5 34.5 3535

35 Apr. 2014

5.33

34

34 43

34

34.5 Jan. 2015

33.5

43 34

34 34 34

34 34.5

34.5 Feb. 2015

33.5 33.5

33.5

34 34 34

34.534.5

5.43

Mar. 2015

34 34

34.5 35 Apr. 2015

Jan. 30, 2012 Jan. 30, 2015

33

33.5 33.534 Sep. 2011

33 33

33

33 33

33.5 Oct. 2011

33 33

33 33.5

33.5 Nov. 2011

33.5

34 34

34 3434.5 Dec. 2011

33

33.5 33.5 34 Sep. 2012

33 33 33.5

33.5 Oct. 2012

33

33 33

33 33.5 Nov. 2012

33 33

33 33.5

33.5

34 34 Dec. 2012 34

3232.53333.5 34Sep. 2013

32.5 33

33

3333.5

Oct. 2013

32.5

33 33

3333 33

33.5 Nov. 2013 34

34 34 34

34 34

34.5 Dec. 2013

33

33 33.5 33.5

34

Sep. 2014 34

33 33.5 33.5

3433.5

34 Oct. 2014

33

33 33

33.534 Nov. 2014

34

34 34

34 34 34.5 Dec. 2014 NIFSAquarius V4 Aquarius V5

JMANIFS Aquarius V4 Aquarius V5

Fig. 4. Monthly Aquarius salinity distribution from January to April in 2012-2015.

(6)

192

이동규

하게불어

2013

^년

8

^월의^동해^남부^{해상에서의}^저염수는^염분

년

-2015

년동안블라디보스톡근해에형성된해빙의면

적을위성으로관측된해빙관측자료

(ice coverage map)

로부

터결빙된해역

(Fig. 7

에청색원으로표시된해역내의적색으

로경계를표시한백색해빙영역

)

동중국해에서동해로유입되는저염수는

9

^월에^최대로^동해 남부에분포하고

11

월동해전역에

33.5 psu

이하의해수가분 포하게된다

(Fig. 9). 7

월

- 8

월동중국해의해상풍

(Fig. 6)

의강

도에따라저염수의분포및최저염분이변동을하며

, 2013

년

7

월

-8

월에동중국해에서남풍이가장강하여저염수의세력 이관측기간

4

^년^중^가장^컸으며

2014

^년은

8

^월^평균^동중국해 에서의해상풍은북풍이었고동해에서저염수의영향은가장 적었다

.

블라디보스톡연안에서생성된저염수는남하하여울 릉분지에서대한해협으로유입된저염수와섞여동진하게되 나

(Lee and Lee, 2017),

타타르해협남쪽연안의저염수는시

관측되었다

.

34.0 psu

이상의고염수는

12

월부터대한해협을통해동해로

유입되어동해남부에고염수가분포하게되나

,

^고염수와^저염

수가해에따라복잡한양상을보이면서분포한다

(Fig. 9).

아

(Fig. 8)

동해북부에서의겨울철저염수와의관계가있는것

으로나타났다

.

일본연안에

3

월부터저염수가나타나기시작 하여

5

월까지분포하였으나

(Fig. 4), 2014

년은

5

월부터늦게나 타났다

. 2015

년

3

월에는

2012-2013

년과정반대의염분분포

(

동해북부

-

^저염수

,

^동해^남부

-

^고염수

)

^를^보였으나

4

^월부터^저염 수가분포하기시작하여그에대한원인규명이필요하나본연 구의주제인가을철동해남부해역에분포하는저염수와달라 이에대한논의는여기서하지않는다

. 4

월에는일본연안을제

외한동해전역에

34.0 psu

이상의고염수가분포하여저염수가

완전히소멸되었다

.

월평균 분포를 통한 동해 저염수의 생성-확장-소멸 저염수의 형성

관측기간동안평균한월평균염분분포를

Fig. 10

에

1

개월

간격으로

World Ocean Atlas 2013 (WOA13) (WOA, 2015)

의

2005-2012

년월평균염분과같이제시하였다

.

전섹션에 서 논의한바와같이동해남부의일본근해해역에는

3

월부 터저염수가나타나기시작하여

6

^월에는^거의^분포하지^않으나

129°E 132°E 135°E 138°E 141°E

44°N

42°N

40°N

38°N

36°N

20 15 10 5 10 -5 -10 -15 -20

44°N

42°N

40°N

38°N

36°N

20 15 10 5 10 -5 -10 -15 -20

2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 Year

-2 6 5 4 3 2 1 0 -1 7

8

2012/01 2013/01 2014/01 2015/01

700 600 500 400 300 200 100 0

-5 -6 -7 -8 -9 -10 -11 -12

129°E 132°E 135°E 138°E 141°E

44°N

42°N

40°N

38°N

36°N

35 34.5 34 33.5 33 32.5 32 JulyAugust

Ice Area Air Tem

44°N 40°N

36°N

130°E 135°E 140°E 5 4 3 2 1

0 130°E 135°E 140°E 5 4 3 2 1 0 30°

35°

40°

45 50°

55°

30°

35°

40°

45 50°

55°

120° 125° 130° 135° 140° 145°

1 10 17

1 3 7 8

0 2 2 2 6

1

3 0

(b) Bias×0.01 5

20 20 14 13 23 40 40 23 15 13 13 18 25 36

2 13 13 12 14 17 19 19 16 13 14 11 11 13 13 14 14 14 16 15

12 13 13 12 12 15 18 10 9 12 13 14 12 11 12 12 13 12 16

7 6 6 10 10

10 8 9 8

9 9 9 6

(a) Bias×0.1

N

J

33

33 33.5

33.5

33.5 33.5

33.3 33.3

33 33.3

33.3 CDW

NKCC

Changjiang

Vladivostok

?

EKWC

Jan Feb

Fig. 5. Monthly Aquarius salinity distribution from May to August in 2012-2015.