Summer temperature in the eastern part of southern South America: its variability in the twentieth century and a teleconnection with Oceania
The 1907-2001 summer-to-summer surface air temperature variability in the eastern part of southern South America (SSA, partly including Patagonia) is analysed. Based on records from instruments located next to the Atlantic Ocean (36°S-55°S), we define indices for the interannual and interdecadal tim...
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ftreroch:oai:doc.rero.ch:325284 2023-05-15T18:07:34+02:00 Summer temperature in the eastern part of southern South America: its variability in the twentieth century and a teleconnection with Oceania Jacques-Coper, Martín Brönnimann, Stefan 2019-05-29T11:50:51Z http://doc.rero.ch/record/325284/files/382_2013_Article_2038.pdf eng eng http://doc.rero.ch/record/325284/files/382_2013_Article_2038.pdf 2019 ftreroch 2023-02-16T17:33:13Z The 1907-2001 summer-to-summer surface air temperature variability in the eastern part of southern South America (SSA, partly including Patagonia) is analysed. Based on records from instruments located next to the Atlantic Ocean (36°S-55°S), we define indices for the interannual and interdecadal timescales. The main interdecadal mode reflects the late-1970s cold-to-warm climate shift in the region and a warm-to-cold transition during early 1930s. Although it has been in phase with the Pacific Decadal Oscillation (PDO) index since the 1960s, they diverged in the preceding decades. The main interannual variability index exhibits high spectral power at ~3.4years and is representative of temperature variability in a broad area in the southern half of the continent. Eleven-years running correlation coefficients between this index and December-to-February (DJF) Niño3.4 show significant decadal fluctuations, out-of-phase with the running correlation with a DJF index of the Southern Annular Mode. The main interannual variability index is associated with a barotropic wavetrain-like pattern extending over the South Pacific from Oceania to SSA. During warm (cold) summers in SSA, significant anticyclonic (cyclonic) anomalies tend to predominate over eastern Australia, to the north of the Ross Sea, and to the east of SSA, whereas anomalous cyclonic (anticyclonic) circulation is observed over New Zealand and west of SSA. This teleconnection links warm (cold) SSA anomalies with dry (wet) summers in eastern Australia. The covariability seems to be influenced by the characteristics of tropical forcing; indeed, a disruption has been observed since late 1970s, presumably due to the PDO warm phase. Other/Unknown Material Ross Sea RERO DOC Digital Library Ross Sea Patagonia Pacific New Zealand |
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Open Polar |
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RERO DOC Digital Library |
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ftreroch |
language |
English |
description |
The 1907-2001 summer-to-summer surface air temperature variability in the eastern part of southern South America (SSA, partly including Patagonia) is analysed. Based on records from instruments located next to the Atlantic Ocean (36°S-55°S), we define indices for the interannual and interdecadal timescales. The main interdecadal mode reflects the late-1970s cold-to-warm climate shift in the region and a warm-to-cold transition during early 1930s. Although it has been in phase with the Pacific Decadal Oscillation (PDO) index since the 1960s, they diverged in the preceding decades. The main interannual variability index exhibits high spectral power at ~3.4years and is representative of temperature variability in a broad area in the southern half of the continent. Eleven-years running correlation coefficients between this index and December-to-February (DJF) Niño3.4 show significant decadal fluctuations, out-of-phase with the running correlation with a DJF index of the Southern Annular Mode. The main interannual variability index is associated with a barotropic wavetrain-like pattern extending over the South Pacific from Oceania to SSA. During warm (cold) summers in SSA, significant anticyclonic (cyclonic) anomalies tend to predominate over eastern Australia, to the north of the Ross Sea, and to the east of SSA, whereas anomalous cyclonic (anticyclonic) circulation is observed over New Zealand and west of SSA. This teleconnection links warm (cold) SSA anomalies with dry (wet) summers in eastern Australia. The covariability seems to be influenced by the characteristics of tropical forcing; indeed, a disruption has been observed since late 1970s, presumably due to the PDO warm phase. |
author |
Jacques-Coper, Martín Brönnimann, Stefan |
spellingShingle |
Jacques-Coper, Martín Brönnimann, Stefan Summer temperature in the eastern part of southern South America: its variability in the twentieth century and a teleconnection with Oceania |
author_facet |
Jacques-Coper, Martín Brönnimann, Stefan |
author_sort |
Jacques-Coper, Martín |
title |
Summer temperature in the eastern part of southern South America: its variability in the twentieth century and a teleconnection with Oceania |
title_short |
Summer temperature in the eastern part of southern South America: its variability in the twentieth century and a teleconnection with Oceania |
title_full |
Summer temperature in the eastern part of southern South America: its variability in the twentieth century and a teleconnection with Oceania |
title_fullStr |
Summer temperature in the eastern part of southern South America: its variability in the twentieth century and a teleconnection with Oceania |
title_full_unstemmed |
Summer temperature in the eastern part of southern South America: its variability in the twentieth century and a teleconnection with Oceania |
title_sort |
summer temperature in the eastern part of southern south america: its variability in the twentieth century and a teleconnection with oceania |
publishDate |
2019 |
url |
http://doc.rero.ch/record/325284/files/382_2013_Article_2038.pdf |
geographic |
Ross Sea Patagonia Pacific New Zealand |
geographic_facet |
Ross Sea Patagonia Pacific New Zealand |
genre |
Ross Sea |
genre_facet |
Ross Sea |
op_relation |
http://doc.rero.ch/record/325284/files/382_2013_Article_2038.pdf |
_version_ |
1766179772460695552 |