E-hyung Park, Doo-hee Ryu, and Hyun-kyung Kim Climate Prediction Division Korea Meteorological Administration Overview of 2012/2013 winter over South Korea.

E-hyung ParkE-hyung Park, Doo-hee Ryu, Doo-hee Ryu, and Hyun-kyung , and Hyun-kyung

KimKimClimate Prediction DivisionClimate Prediction Division

Korea Meteorological AdministrationKorea Meteorological Administration

Overview of Overview of 2012/2013 2012/2013

winter over Southwinter over South KoreaKorea

2. Temp. & Precip. over Korea2. Temp. & Precip. over Korea

4. Summary4. Summary

1. Temp. & Precip. over East Asia1. Temp. & Precip. over East Asia

3. Notable Events & Season Monitoring3. Notable Events & Season Monitoring

ContentsContents

DecemberDecember JanuaryJanuary FebruaryFebruary

Temperature & Precipitation Temperature & Precipitation

over EAover EANovemberNovember

Temperature over South KoreaTemperature over South Korea

Anomaly: Anomaly: -1.6-1.6℃℃ -3.2℃

-1.1℃

Above NormalBelow Normal

-0.4℃

normalabovebelow

Mean (-1.0℃℃)

December January February

12.1 12.11 12.21 1.1 1.11 1.21 2.1 2.11 2.21

Daily Mean Temperature anomaly (℃)

Precipitation over South KoreaPrecipitation over South Korea

12.1 12.11 12.21 1.1 1.11 1.21 2.1 2.11 2.21

261%

103%

149%

Ratio to normal:Ratio to normal: 162%162%

Total (139.3mm)

normalabovebelow

Daily averaged amount of precipitation( ㎜ )

December January February

BlockingBlocking

•Atmospheric blocking made frequently in Pacific and Atlantic Ocean.

•A quasi-stationary blocking high over the North Pacific, which may exert an influence on the East Asian trough and indirectly affect the cold surge pathways in East Asia (Cheung et al., 2012).

•The region around the Ural Mountains is the third preferred region for blocking occurrence

•A strong positive height anomaly over the Urals in winter is related to a colder surface temperature in East Asia (Li, 2004).

•The circulation pattern over the Uarls is one of the critical factors in winter seasonal prediction for East Asia (Li, 2004).

DJF 1950~2000

Blocking Frequency

Schematic illustration of Ural

blocking

Long-lasting cold episode and Long-lasting cold episode and

cold surgecold surge

• From late November to early December, an blocking high occurred over the Bering Sea Block the west to east progression of the upper level airflow A cold upper level trough passed through over East Asia

500hPa GPH anomaly (21 Nov. to 10 Dec.)

11/21 11/26 12/1 12/6 12/11 12/16 12/21 12/26 1/1 1/6

November

3rd

Daily mean temperature anomaly (℃)

January1st

December

-1.4℃(-4.4℃)

-0.3℃(-1.6℃)

-3.3℃(-3.7℃)

-5.8℃(-5.1℃)

SAT anomaly (21 Nov. to 10 Dec.)

500hPa GPH anomaly (11 Dec. to 10 Jan.)

• From mid to late December, the blocking high occurred over the Ural Mountains The enhanced northerly cold advection increases mass convergence in the upper troposphere over Siberia The Siberian High was significantly developed Cold air outbreak in East Asia

11/21 11/26 12/1 12/6 12/11 12/16 12/21 12/26 1/1 1/6

November

3rd

Daily mean temperature anomaly (℃)

January1st

December

-1.4℃(-4.4℃)

-0.3℃(-1.6℃)

-3.3℃(-3.7℃)

-5.8℃(-5.1℃)

• In December, the monthly In December, the monthly mean temperature anomaly mean temperature anomaly over South Korea was -3.2°C. over South Korea was -3.2°C. It was the coldest since 19It was the coldest since 197373.• The record-breaking The record-breaking minimum temperatures were minimum temperatures were recorded in recorded in 33 to to 44 January January 20120133 over South Korea since over South Korea since record began. record began.

Long-lasting cold episode and Long-lasting cold episode and

cold surgecold surge

December January February

NCEP Climatology2012/2013

Daily variations of maximum pressure of SH (hPa)

80~120°E, 40~60°N

MSLP anomaly (11 Dec. to 10 Jan.) SAT anomaly (11 Dec. to 10 Jan.)

Long-lasting cold episode and Long-lasting cold episode and

cold surgecold surge

12.1 12.11 12.21 1.1 1.11 1.21 2.1 2.11 2.21

261%

103%

149%

Daily averaged amount of Precipitation( ㎜ )

Siberian HighSiberian High

Warm & Humid

Warm & Humid

AirAir

Upper level Upper level Cold AirCold Air

December

January February

Frequent snow and rain in winterFrequent snow and rain in winter

• In December, the monthly total precipitation over In December, the monthly total precipitation over South Korea was 60.4South Korea was 60.4 ㎜㎜ . . It was theIt was the 2 2ndnd wettest wettest since since 19197373.. The rainy days (days with more than 0.1 The rainy days (days with more than 0.1 ㎜㎜ ) was ) was 11.2 days (6.6 days), which was 11.2 days (6.6 days), which was ranked 1ranked 1stst since 1973. since 1973.

• In early-February, the total precipitation was 45.0In early-February, the total precipitation was 45.0 ㎜㎜ . . It It was thewas the 1 1stst since 19since 197373.. The rainy days was 5.4 days The rainy days was 5.4 days (1.9 days), which was ranked 1(1.9 days), which was ranked 1stst since 1973. since 1973.

• The number of rainy days during in the wintertime was The number of rainy days during in the wintertime was 25.5 days 25.5 days (19.8 days), which was ranked the 3(19.8 days), which was ranked the 3rdrd largest since largest since 1973. 1973.

Stratospheric Sudden WarmingStratospheric Sudden Warming

Mean (1991~2004) 2012/2013

Max & Min (1991~2004)

SummarySummary

1. Wintertime(2012/2013) climate over Korea 1. Wintertime(2012/2013) climate over Korea - Temperature: - Temperature: below normal below normal ((-1.6℃-1.6℃)) - Precipitation: - Precipitation: above normal above normal ((162%162%)) - Rainy days: 25.5 days (3 - Rainy days: 25.5 days (3rdrd largest since 1973) largest since 1973)

2. The long-lasting cold episode and cold surge is strongly associated with the blocking high over the North Pacific and Ural Mountains. Especially, the Ural blocking intensifies the Siberian high and triggers a cold air outbreak in East Asia.

3. Continuously warm and humid southwesterly flow collided frequently with cold and dry continental upper air over the Korean Peninsula which induced severe atmospheric instability.

-3.2℃

-1.1℃

Above NormalBelow Normal

-0.4℃

12.1 12.11 12.21 1.1 1.11 1.21 2.1 2.11 2.21

Daily mean temperature anomaly (℃)

December January February

NCEP Climatology2012/2013

Daily variations of maximum pressure of SH (hPa)

80~120°E, 40~60°N

Siberian High & SATSiberian High & SAT

2009/2010 DJF 2010/2011 DJF

2011/2012 DJF 2012/2013 DJF

SAT anomalySAT anomaly

Regression map & Anomalous Regression map & Anomalous patternpattern

110oE 150oE 170oW 130oW 90oW 20oS

0o

20oN

-30

-15

0

15

30OLR 2012D/13J Anomalous pattern (Clim: 1979-2011 DJF)

Korea Precip. (DJF) & OLR(DJF): 1979/80~2011/12

Velocity Potential and SST Velocity Potential and SST AnomalyAnomaly

DecemberDecember

SST monthly Anomaly