2009 global climate:A tale of five timeseries

• Global mean temperature

• El Niño / Southern Oscillation (ENSO)

• Pacific Decadal Oscillation

• Annular modes north and south

Todd Mitchell, Climate Impacts Group February 2010

0.56 °C in 2009 (tie with 2006 for 6th warmest, 1901-2000 mean)

The decade 2000-09 was the warmest on record (0.54C).

• 2005 the warmest, followed by 1998• the 2000-09 decade is the warmest on record

Southern annular mode positive early in 2009

• central - southeast Australia drought continues• tropics not typical warm ENSO signal• wet Mediterranean consistent with negative NAM, NAO

El Niño / Southern Oscillation (ENSO)

• with respect to 1971-2000.• 1.04, 1.67, 1.83 °C in October, November and December, respectively• 0.46°C 2009-mean, October-November-December mean 1.48°C• 3 Atlantic hurricanes this year (fewer hurricanes during warm ENSOs)

Warm ENSO peaking now and will diminish throughMay-June-July

• 1900-93 climatology• 2009 mean -0.6 standard deviations• NOAA coupled forecast model predicts positive PDO

(warm west coast SST anomalies) through the Spring

Northern annular mode

December 2009 largest negative value since at least 1950.

January throughDecember averages

Typical Northern Annular Mode

temperature and preciptation anomalies

Typical Northern Annular Mode

temperature and preciptation anomalies

• central - southeast Australia drought continues• tropics not typical warm ENSO signal• wet Mediterranean consistent with negative NAM, NAO

• minimum in September

• September 2009 the 3rd lowest since 1979

1895-2008

• Record warm Seattle July• Cool and wet in central and eastern U.S.• Modeling studies suggest this pattern was related to tropical SSTs

U.S. Wildland Fires

February-March-April temperatureforecast: Enhanced probability of warmer than normal temperatures in the Pacific Northwest(classic ENSO pattern)

February-March-Aprilpreciptation forecast:increased probability of drier than normalin the Pacific Northwest (classic ENSO pattern)