RECENT TRENDS OF AIR AND WATER TEMPERATURE AND ICE COVER IN THE FAR-EASTERN SEAS

Pacific Fisheries Research Centre (TINRO-Centre) 690091 Shevchenko Alley, 4, Vladivostok, Russia

E-mail: eustinova@mail.ru

PICES-2013 (S6)

Elena I. Ustinova and Yury D. Sorokin

Recent climatic trends (for the last semicentennial period and 30-year running trends) and low-frequency variability of various environmental parameters are evaluated for different areas of the Japan/East, Okhotsk, and Bering Seas. Climatically significant parameters for monitoring are selected on the following principles: duration, uniformity and regularity of observations and the parameters' utility for marine ecosystem studies

Air temperature: Monthly mean air temperature data at coastal meteorological stations published by Russian

Hydrometeorological Agency (as monthly and annual reports and climatic directories).

Monthly mean air temperature data at the meteorological stations data from NASA GISS

(http://www.giss.nasa.gov/data/update/gistemp)

Historical and contemporary sources of regional data of the observations on various “thermal” parameters

-station with air temperature-station with water temperatureNemuro

Yuzno-Kuril'skKuril'sk

Simushir

Abashiry

Wakkanai C. Kril'onKorsakov

Y-SakhalinskVzmor'eC. Terpeniya

Poronaysk

KomrvoNik.-na-Amure

LitkeB. Shantar

AyanKhanyangda

UlyaOkhotsk Ushki

Nagaevo

C. Brat'evYamsk

ShelikhovaPestraya Dresva

Taygonos

Icha

Ozernaya Petropavlovsk-Kamchatsky

Semyachiki

C. AfricaUst-Kamchatsk

Ossora

Tilichiki

Ust-ApukaTopata-Olutorskaya

Natal'yaGavriil

Ugol'naya

AnadyrEgvekinot Provideniya

Uelen Nome

St. Paul

Gold Bay

SST: Time series of the monthly mean SST (COBE-SST) and 10-day mean from 1950 to latest

month for 1 degree square of the Pacific Ocean from the Real Time Data Base, NEAR-GOOS

http://goos.kishou.go.jp/rrtdb

Time series of the monthly mean SST (HadISST) for 1 degree square from the Hadley Centre

(Rayner et al., 2003) http://www.metoffice.gov.uk/hadobs/hadisst

SST trends are estimated for the selected sub-regions 1-7 and using empirical orthogonal functions for each sea.

Bering Sea:1 – Western 2 – Eastern

Okhotsk Sea: 3 – Northern 5 – Southern 4 – Western Kamchatka sub-region

Japan Sea: 6 – Northern 7 – Southern

Bering Sea:1 – Western 2 – Eastern

Okhotsk Sea: 3 – Northern 5 – Southern 4 – Western Kamchatka sub-region

Japan Sea: 6 – Northern 7 – Southern

Ice cover: Time series of the ice cover in the Okhotsk Sea in March (annual maximum) for 1929-1956

collected by Kryndin (1964) from various visual observations (shipboard, aircraft, coastal).

Regular ten-days aircraft observations conducted by Russian Hydrometeorological Service:

Okhotsk Sea for 1957-1991, Bering Sea and Japan Sea (Tatar Strait) for 1960-1991.

Satellite information obtained from Far-Eastern Regional Center, Khabarovsk (1992-1998) and

from National Ice Center U.S.A (since 1999) (http://www.natice.noaa.gov/pub/west_arctic)

Ice charts of the Japanese Meteorological Agency for the Okhotsk Sea (1998-2013).

http://www.natice.noaa.gov/pub/west_arctic

SAT trends (Review of the state and tendencies of climate, 2012)

Winter

Summer

Spring

Autumn

SAT trends The principal features of the regional climatic tendencies in the air temperature:

-strong irregularity and inhomogeneity in

time and space connected with specific

macrocirculating atmospheric processes

on the boundary between Eurasian

continent and the Pacific Ocean;

- maximal warming in winter and spring

over southern part of Russian Far East

and over the coast of Japan and

Southern Kamchatka;

- weak negative trends in the areas to

the north from the Okhotsk Sea and

to the west from the Bering Sea in winter;

- difference between summer

and winter temperatures

decreases on the coast of the Japan/East

Sea and increases on the North-Western

coast of the Okhotsk Sea,

i.e., the continentality increases

on the Northern Far East

Winter

Summer

SST anomalies in the selected sub-regions of the

Japan/East Sea (6-7)

Японское море

6

y = 0.02x - 44.18

R2 = 0.55

-1.5

-1.0

-0.5

0.0

0.5

1.0

1.5

1950 1960 1970 1980 1990 2000 2010

6 7 тренд

Winter

Winter

y = 0,1191x - 236R2 = 0,2138

-10

-8

-6

-4

-2

0

2

4

6

8

10

1950 1960 1970 1980 1990 2000 2010

ЕОF 1

trend

1 EOF of SST in the

Japan/East Sea

Bering Sea

2

y = 0.01x - 18.98

R2 = 0.12

1

y = 0.01x - 18.24

R2 = 0.28

-2.0

-1.5

-1.0

-0.5

0.0

0.5

1.0

1.5

2.0

1950 1960 1970 1980 1990 2000 2010

1 2 trend

Okhotsk Sea

3

y = 0.02x - 42.65

R2 = 0.57

4

y = 0.01x - 29.39

R2 = 0.50

5

y = 0.02x - 45.93

R2 = 0.54

-2.0

-1.5

-1.0

-0.5

0.0

0.5

1.0

1.5

2.0

1950 1960 1970 1980 1990 2000 2010

3 4 5 trend

Japan Sea

6

y = 0.02x - 34.59

R2 = 0.31

-2.0

-1.5

-1.0

-0.5

0.0

0.5

1.0

1.5

2.0

1950 1960 1970 1980 1990 2000 2010

6 7 trend

Okhotsk Sea

4

y = 0.01x - 19.27

R2 = 0.09

-2.5

-2

-1.5

-1

-0.5

0

0.5

1

1.5

2

2.5

1950 1960 1970 1980 1990 2000 2010

3 4 5 trend

Japan Sea6

y = 0.02x - 35.27

R2 = 0.20

-2.5

-2

-1.5

-1

-0.5

0

0.5

1

1.5

2

2.5

1950 1960 1970 1980 1990 2000 2010

6 7 trend

Bering Sea

1

y = 0.01x - 21.51

R2 = 0.10

-2.5

-2

-1.5

-1

-0.5

0

0.5

1

1.5

2

2.5

1950 1960 1970 1980 1990 2000 2010

1 2 trend

Okhotsk Sea

3

y = 0.02x - 37.49

R2 = 0.50

4

y = 0.01x - 27.74

R2 = 0.31

5

y = 0.015x - 29.75

R2 = 0.34

-2.5

-2.0

-1.5

-1.0

-0.5

0.0

0.5

1.0

1.5

2.0

2.5

1950 1960 1970 1980 1990 2000 2010

3 4 5 trend

Japan Sea

6

y = 0.02x - 38.13

R2 = 0.27

-2.5

-2.0

-1.5

-1.0

-0.5

0.0

0.5

1.0

1.5

2.0

2.5

1950 1960 1970 1980 1990 2000 2010

6 7 trend

Bering Sea

1

y = 0.02x - 38.07

R2 = 0.42

2

y = 0.02x - 35.65

R2 = 0.40

-2.5

-2.0

-1.5

-1.0

-0.5

0.0

0.5

1.0

1.5

2.0

2.5

1950 1960 1970 1980 1990 2000 2010

1 2 trend

Spring Summer Autumn

SST anomalies in the selected sub-regions of the Far-Eastern Seas (1-7)

The main feature of the changes is warming of the surface layer (0.1-0.2 °C per decade), although in the southern Japan/East Sea the positive trend to warming is not significant in all seasons. The contribution of the positive trend to total variance of SST is substantially less in summer than in other seasons.

Summer y = 0.18x - 363.21R2 = 0.10

-25

-20

-15

-10

-5

0

5

10

15

20

25

1950 1960 1970 1980 1990 2000 2010

EOF 1

Trend64.8%

Autumn y = 0.481x - 944.98

R2 = 0.65

-20

-15

-10

-5

0

5

10

15

20

25

1950 1960 1970 1980 1990 2000 2010

EOF 1

mean for 1950-1977

mean for 1978-2011

Trend

75%

Spring

y = 0.26x - 514.04

R2 = 0.39

-20

-15

-10

-5

0

5

10

15

1950 1960 1970 1980 1990 2000 2010

EOF 1

mean for 1952-1977

mean for 1978-2011

Trend

60.6%

Bering Sea

SST trends are estimated using empirical orthogonal functions for each sea.

1 EOF of SST

in the Bering Sea

In spring and autumn the climate regime shift

of 1977/78 was detected.

In summer “true” trend is observed.

EOF 1 of SST Spring

y = 0,1017x - 201,57

R2 = 0,1428

-15

-10

-5

0

5

10

15

20

1950 1960 1970 1980 1990 2000 2010

ЕОF 1

trend

Summer

-20

-15

-10

-5

0

5

10

15

20

1950 1960 1970 1980 1990 2000 2010

ЕОF 1

Autumn

y = 0,1536x - 304,33

R2 = 0,2286

-15

-10

-5

0

5

10

15

20

1950 1960 1970 1980 1990 2000 2010

ЕОF 1

trend

Spring y = 0,3516x - 696,65

R2 = 0,7065

-20

-15

-10

-5

0

5

10

15

1950 1960 1970 1980 1990 2000 2010

ЕОF 1

trend

Summer

-20

-15

-10

-5

0

5

10

15

20

25

30

1950 1960 1970 1980 1990 2000 2010

ЕОF 1

Autumn

y = 0,315x - 623,99

R2 = 0,6539

-20

-15

-10

-5

0

5

10

15

20

1950 1960 1970 1980 1990 2000 2010

ЕОF 1

trend

Okhotsk Sea Japan/East Sea

4 6 8 10 12

1950

1960

1970

1980

1990

2000

2010

4 6 8 10 12

1950

1960

1970

1980

1990

2000

2010

1 2

Variability of SST anomalies in the Bering Sea Positive (negative) anomalies in red (blue) color correspond to

warm (cold) conditions. Time series are standardized.

Variability of SST anomalies in the Okhotsk Sea Positive (negative) anomalies in red (blue) color correspond to

warm (cold) conditions. Time series are standardized.

2 4 6 8 10 12

1950

1960

1970

1980

1990

2000

2010

2 4 6 8 10 12

1950

1960

1970

1980

1990

2000

2010

N S

Variability of SST anomalies in the Japan Sea Positive (negative) anomalies in red (blue) color correspond to

warm (cold) conditions. Time series are standardized.

“S” is % to the total area of the sea.

The warming is accompanied by decreasing sea ice cover that is the most significant in the Okhotsk Sea (4% per decade) where the ice cover variation agrees well with the changes of air temperature of the Northern Hemisphere. In the Bering Sea and the Tatar Strait the negative trends in ice cover are not statistically significant for 1960-2013. While the Okhotsk Sea ice cover is sensitive to global temperature variations, large-scale oscillations such as El Niño and the Pacific Decadal Oscillation are more important for the Bering Sea ice cover.

Okhotsk Sea

1957-2013

y = -0.41x + 871.81

R2 = 0.29

30

40

50

60

70

80

90

1950 1960 1970 1980 1990 2000 2010

S%

1

2

trend

Bering Sea

1960-2013

15

20

25

30

35

40

45

1950 1960 1970 1980 1990 2000 2010

S%

1

2

Tatar Strait

1960-2013

15

20

25

30

35

40

45

50

55

60

1950 1960 1970 1980 1990 2000 2010

S%

1

2

Okhotsk Sea

March 1929-2013

y = -0.15x + 369.9

R2 = 0.09

40

50

60

70

80

90

100

1920 1940 1960 1980 2000

S%

1

2

trend

Mean winter (Bering Sea, Okhotsk Sea and Tatar Strait) and annual maximum ice cover (in March) in the Okhotsk Sea (1), mean multi-year value (2) and statistically

significant trends with regression equations and determination coefficients R2

100

101

102

0

2

4

6

8

10

12

14x 10

4

Pow

er

Spectr

um

s

Period(Years/Cycle)

18.8

8.46.7

2.7

100

101

102

0

1

2

3

4

5

6

7x 10

4

Pow

er

Spectr

um

s

Period(Years/Cycle)

3.8

7.3

8.8

12.8

17.1

46.1

100

101

102

0

0.5

1

1.5

2

2.5x 10

5

Pow

er

Spectr

um

s

Period(Years/Cycle)

2.4

18.2

11.2

56

10.1

Power spectrums of ice cover in the Far-Eastern Seas

Bering Sea

The spectral analysis of time series of the maximum annual ice cover showed that now the basic contribution to the variance gave the scale about 50 years (Okhotsk and Bering Seas), 18,2 (Okhotsk Sea)-18.8 (Tatar Strait), quasy-decadal scale (Okhotsk and Bering Seas), and 7-8 years (Bering Sea and Tatar Strait) oscillations. In the Okhotsk Sea 2.4 year scale is very significant.

(Methodology by Vilnis Liepins, 1997)

Okhotsk Sea

Tatar Strait

Positive (negative) ice coverage anomalies in blue (red) color correspond to cold (warm) conditions. Time series are standardized.

-3.5

-3

-2.5

-2

-1.5

-1

-0.5

0

0.5

1

1.5

2

2.5

3

3.5

1960

1965

1970

1975

1980

1985

1990

1995

2000

2005

2010

Dec Jan Feb Mar Apr May1960

1965

1970

1975

1980

1985

1990

1995

2000

2005

2010

Dec Jan Feb Mar Apr May1960

1965

1970

1975

1980

1985

1990

1995

2000

2005

2010

Dec Jan Feb Mar Apr

Bering Sea Okhotsk Sea Tatar Strait

Variability of ice coverage anomalies in the Far-Eastern Seas

Winter North Hemispheric temperature anomalies, annual maximal ice cover in the Okhotsk Sea and its polynomial trends

R2 = 0.66

R2 = 0.26

40

50

60

70

80

90

100

1925 1935 1945 1955 1965 1975 1985 1995 2005

-60

-40

-20

0

20

40

60

80

100

120

Ice cover Ta NH

Shifts in the mean for Ice_Bering, 1960-2012

Probability = 0.1, cutoff length = 10

0

5

10

15

20

25

30

35

40

45

1960

1963

1966

1969

1972

1975

1978

1981

1984

1987

1990

1993

1996

1999

2002

2005

2008

2011

Shifts in the mean for Ice_Okhotsk, 1960-2012

Probability = 0.1, cutoff length = 10

01020

3040506070

8090

100

1960

1963

1966

1969

1972

1975

1978

1981

1984

1987

1990

1993

1996

1999

2002

2005

2008

2011

Shifts in the mean for Ice_Tatar, 1960-2012

Probability = 0.1, cutoff length = 10

0

10

20

30

40

50

60

1960

1963

1966

1969

1972

1975

1978

1981

1984

1987

1990

1993

1996

1999

2002

2005

2008

2011

Examples for Far-Eastern Seas: shifts in ” ice variables” The shift of 1978 and 2008 is strongest for the Bering Sea in the last 52 years. The shift of 1989 is strongest for the Tatar Strait The shift of 1984 : is strongest for the Okhotsk Sea

This is the RS index for regional “thermal” time series. The shift of 1989 is strongest. The shift of 1989: to relative warming for the Japan/East and Okhotsk seas

Summary of regional regime shift indices in the mean

Probability = 0.1, cutoff length = 10

00.050.1

0.150.2

0.250.3

0.35

0.40.450.5

1950

1954

1958

1962

1966

1970

1974

1978

1982

1986

1990

1994

1998

2002

2006

2010

1977

1989

1998

2004

Conclusions

Recent climatic trends and low-frequency variability of various environmental parameters are evaluated for different areas of the Japan/East, Okhotsk, and Bering Seas:

SST trends are estimated using empirical orthogonal functions for each sea. The main

feature of the changes is warming of the surface layer (0.1-0.2 °C per decade), although in the southern Japan/East Sea the positive trend to warming is not significant in all seasons. The contribution of the positive trend to total variance of SST is substantially less in summer than in other seasons.

The warming is accompanied by decreasing sea ice cover that is the most significant in

the Okhotsk Sea (4% per decade) where the ice cover variation agrees well with the changes of air temperature of the Northern Hemisphere. In the Bering Sea and the Tatar Strait the negative trends in ice cover are not statistically significant for 1960-2013.

While the Okhotsk Sea ice cover is sensitive to global temperature variations, large-scale

oscillations such as El Niño and the Pacific Decadal Oscillation are more important for the Bering Sea ice cover.

For thermal variables, the regime shifts of 1977/78 (to warming) and 2007/2008 (to

cooling) are the strongest for the Bering Sea, the shift of 1988/1989 (to warming) for the Japan/East Sea, and regional shift of 1983/84 (to warming) for the Okhotsk Sea.

Thank you for attention!