WORKSHOP: LESSONS FROM THE 2007 ICE MINIMUM

Atmospheric temperature and modes-of-

variability 2000-07 and earlier analogsWWW.BJERKNES.UIB.NO

Emerging Arctic Amplification as Seen in the NCEP/NCAR Reanalysis 

Mark C. Serreze, Andrew P. Barrett, Julienne Stroeve, David N. KindigNational Snow and Ice Data Center,

Cooperative Institute for Research in Environmental SciencesUniversity of Colorado, Boulder, CO

 Marika M. Holland

National Center for Atmospheric ResearchBoulder CO

 Rises in surface and lower troposphere air temperatures through the 21st century are

projected to be especially pronounced over the Arctic Ocean during the cold season. This

Arctic amplification reflects loss of the sea ice cover, allowing for strong heat transfers

from the ocean to the atmosphere. Consistent with observed reductions in sea ice

extent, fields from the NCEP/NCAR reanalysis suggest emergence of Arctic amplification

in the last decade during the autumn season.

WORKSHOP: LESSONS FROM THE 2007 ICE MINIMUM

Figure 1: Anomalies by year (x axis) and month (y axis) from 1979-2007 of: (a) sea ice extent; b) 2-m (surface air) temperatures, both from the NCEP reanalysis. Results are for a specified Arctic Ocean domain/

WORKSHOP: LESSONS FROM THE 2007 ICE MINIMUM

Figure 2. Latitude by height (hPa) cross sections of autumn (September through November) temperatures anomalies, relative to 1979-2007 means: a) 1993-1997'; b) 1998-2002; c) 2003-2007.

WORKSHOP: LESSONS FROM THE 2007 ICE MINIMUM

EOF1 EOF2 EOF3

NAO-related PNA-related No known teleconnection

Arctic SAT modes of variability, 20th century winter

WORKSHOP: LESSONS FROM THE 2007 ICE MINIMUM

Figure. (a) Winter (DJF) SAT anomalies (deg C) 2000-06, (b) EOF3 wintertime modified after Semenov and Bengtsson [2003].

WORKSHOP: LESSONS FROM THE 2007 ICE MINIMUM

Arctic SAT modes of variability, recent warmthand early 20th century warmth

WORKSHOP: LESSONS FROM THE 2007 ICE MINIMUM

SAT PC3 40–80°N (NCEP)

SAT PC3 40–80°N (AARI)

SST anomalies 40–60°N

AMO imprint on high-latitude SAT

Fig. North Atlantic SSTs and high-latitude SAT patterns.

WORKSHOP: LESSONS FROM THE 2007 ICE MINIMUM

Atmospheric temperature and modes-of-variability 2000-07 and earlier analogs

WWW.BJERKNES.UIB.NO

Recent warming: TATM anomalies, winter onset season (Oct-Dec) Arctic amplification emerging strongly SAT increase linked to sea ice decrease Arctic warming driven from the “bottom up”

Recent winter warming patterns similar to early 20th century

warming, superposed on a background of recent general

warming at high latitudes SAT patterns linked to sea-ice decreases Temporal evolution nearly identical to Atlantic Multidecadal

Oscillation (AMO) time series