Project

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Southern hemisphere atmospheric circulation variability over the past millennium: a multi-proxy reconstruction and climate model comparison

Applicant Neukom Raphael
Number 131551
Funding scheme Fellowships for prospective researchers
Research institution
Lamont-Doherty Earth Observatory Columbia University
School of Earth Sciences University of Melbourne
Institution of higher education Institution abroad - IACH
Main discipline Climatology. Atmospherical Chemistry, Aeronomy
Start/End 01.07.2010 - 31.07.2011
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All Disciplines (5)

Discipline
Climatology. Atmospherical Chemistry, Aeronomy
Oceanography
Other disciplines of Environmental Sciences
Hydrology, Limnology, Glaciology
Meteorology

Keywords (4)

Climate variability; Climate reconstruction; Southern Hemisphere; Climate change

Lay Summary (English)

Lead
Lay summary
The aim of this project was to gather more information about climate variations in the Southern Hemisphere over the las millennium. Such climate reconstructions are important in order to improve our understanding of the climate system and to enhance accuracy of climate change projections. So far, reliable and well replicated climate reconstructions do only exist for the Northern Hemisphere, whereas existing reconstructions from the Southern Hemisphere are based on a very sparse data basis. Within this project, all currently existing paleoclimate data from the Southern Hemisphere were collected and organized in a database. These so-called "proxy" records consist of time series derived from tree-rings, ice cores, corals, lake and marine sediments, speleothems and documentary evidence. Records from more than 300 sites were analized and screened for their potential for climate reconstruction of high temporal resolution (annual to seasonal). We then used subsets of those records to reconstruct temperatures of Australasia as well as the entire Southern Hemisphere. We used a novel reconstruction technique that allows more reliable estimates of reconstruction uncertainties. The reconstructions were compared to existing reconstructions from the Northern Hemisphere and climate model simulations over the last millennium. We find that late 20th century temperatures appear extraordinary in the context of the last millennium, but the warming is not as pronounced as in the Northern Hemisphere. The results allow, for the first time, to perform long-term analyses of climate variability on continental scales within the Southern Hemisphere and reliable inter-hemispheric comparisons.
Direct link to Lay Summary Last update: 21.02.2013

Responsible applicant and co-applicants

Publications

Publication
Antarctic temperature changes during the last millennium: evaluation of simulations and reconstructions
Goosse H., Braida M., Crosta X., Mairesse A., Masson-Delmotte V., Mathiot P., Neukom R., Oerter H., Philippon G., Renssen H., Stenni B., van Ommen T., Verleyen E. (2012), Antarctic temperature changes during the last millennium: evaluation of simulations and reconstructions, in Journal of Climate, 55, 75-90.
Multi-century tree-ring based reconstruction of the Neuquén River streamflow, northern Patagonia, Argentina
Mundo Ignacio, Masiokas Mariano, Villalba Ricardo, Morales Mariano, Neukom Raphael, LeQuesne Carlos, Urrutia Rocio, Lara Antonio (2012), Multi-century tree-ring based reconstruction of the Neuquén River streamflow, northern Patagonia, Argentina, in Climate of the Past, 8, 815-829.
Southern Hemisphere high-resolution palaeoclimate records of the last 2000 years
Neukom Raphael, Gergis Joelle (2011), Southern Hemisphere high-resolution palaeoclimate records of the last 2000 years, in The Holocene, 1-24.
Reconstructed and simulated Medieval Climate Anomaly in southern South America
Luterbacher Jürg, Neukom Raphael, González-Rouco Fidel, Fernandez-Donado Laura, Raible Christoph, Zorita Eduardo (2011), Reconstructed and simulated Medieval Climate Anomaly in southern South America, in PAGES News, 19(1), 20-21.
Unrecorded patterns of tree growth across mid-latitudes in the Southern Hemisphere induced by changes in high-latitude atmospheric circulation
Villalba Ricardo, Lara Antonio, Masiokas Mariano, Urrutia Rocio, Cook Ed, Christie Duncan, Mundo Ignacio, Boninsegna Jose, Fenwick Pavla, Neukom Raphael, Allen Kathy, Morales Mariano, Araneo Diego, Mashall Gareth, Srur Ana, Aravena Juan-Carlos, Palmer Jonathan, Unrecorded patterns of tree growth across mid-latitudes in the Southern Hemisphere induced by changes in high-latitude atmospheric circulation, in Nature Geoscience.

Scientific events

Active participation

Title Type of contribution Title of article or contribution Date Place Persons involved
PAGES 2nd Regional 2k Network Meeting 28.07.2011 Bern, Schweiz
XVIII INQUA-Congress 21.07.2011 Bern, Schweiz
1st Antarctica2k Workshop 19.07.2011 Bern, Schweiz
2nd Australasia 2k Workshop 27.04.2011 Perth, Australien


Communication with the public

Communication Title Media Place Year
New media (web, blogs, podcasts, news feeds etc.) AUS2K Palaeoclimate Database Online Database International 01.07.2011
Media relations: print media, online media Climate variability in the southern hemisphere Global Change International 01.01.2011

Associated projects

Number Title Start Funding scheme
154802 Detection of human and natural influences on the climate system: regional insights from the past Millennium 01.05.2015 Ambizione

Abstract

Currently, large scale climate variability in the southern hemisphere (SH) can only be quantified for the short instrumental period starting around AD 1900. To understand the processes driving SH climate variations and to improve predictions of future SH climate, it is essential to analyze spatio-temporally highly resolved paleoclimate data.This project aims at addressing this issue by statistically reconstructing the atmospheric circulation, expressed as sea level pressure (SLP) variability over Australasia, the South Pacific and South America for the past 400-1000 years using natural and documentary proxy data, as well as early instrumental measurements and data from ship log books. The multi-proxy reconstructions, together with associated uncertainties, will then be compared to simulations of global circulation models over the last millennium. The reconstructed SLP pattern will include the quantification of past variations in the El Niño-Southern Oscillation (ENSO), the globally most relevant pattern of climate variability with large impacts on economy and ecology in many regions of the world.The outcome of the project will represent the first large scale circulation reconstructions and spatially explicit paleomodel-reconstruction comparisons of the SH, adding very valuable data to the forthcoming Intergovernmental Panel on Climate Change’s (IPCC’s) fifth assessment report.
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