CAS People

David Schneider, Project Scientist

Antarctic trends compared

To complement the publication, An assessment and interpretation of the observed warming of West Antarctica in the austral spring, I compare trend estimates in numerous Antarctic temperature data sets. While the paper focuses on interpretation of the warming in the austral spring for the period since 1979, the figures linked below compare trends across all seasons for both the data-rich period since 1979 and for the period 1958-present.

Reference

Schneider, D.P., C. Deser, and Y. Okumura, 2012: An assessment and interpretation of the observed warming of West Antarctica in the austral spring, Climate Dynamics 38(1), 323-347, doi:10.1007/s00382-010-0985-x. [Article]

Timeseries

  • Annual timeseries, area-weighted for the whole continent, similar to Figure 2 in Schneider et al. (2012) but including temperature anomalies from GISTEMP for 64-90S (includes some ocean SST) and from the O'Donnell et al. (2011) RLS reconstruction

1979-200x Trend maps

1958-200x Trend maps

Figure Legend

The names of the datasets are indicated above the images. For example, CHAPMAN (79-02) refers to the reconstruction of Chapman and Walsh (2007). The start date of the trend analysis is 1979 and the end date is 2002. READER refers to the in-situ Antarctic station data. Trends in the READER station data are plotted as the circles. The upper left plot for 1979-present has additional data: Sea ice concentration trends are plotted over the ocean area. The scale is reversed so that warm (red-orange) colors indicate reduced sea ice concentration; a value of 0.6 means the trend is minus 6 percent per decade. Squares in the upper-left plot are trends in the Steig et al. (2009) reconstruction of temperatures at automated weather stations (AWS). STEIGv1 is the main reconstruction presented by Steig et al. (2009); STEIGv2, also discussed in Steig et al. (2009), is a modification of that reconstruction based on detrended AVHRR satellite data for calibration. More details are provided in our paper and in references cited therein.

Analysis Notes

The paper provides discussion of, references for, and links to the various datasets. The exception is the newly published ODonnell et al. data, which are posted here. The datasets have somewhat different end dates. The figures are plotted using the most recently available end date; using slightly different end dates does not appreciably impact the seasonality or broad-scale patterns of the trends. These figures are provided for information only (that you may use, with acknowledgement, for education, talks, etc.) and are not official supporting information for the paper.

Other Resources

  • Gareth Marshall's regularly updated page on near-surface air temperature trends at stations around Antarctica. He also mainains a station-based SAM index here.
  • Plotting tools for the regularly updated NASA/Goddard GISTEMP Analysis, which uses many Antarctic stations
  • Antarctic station data from the READER project

CGD People

David Schneider, Project Scientist