Southern South America Multiproxy 1100 Year Temperature Reconstructions
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               World Data Center for Paleoclimatology, Boulder
                                  and
                     NOAA Paleoclimatology Program
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NOTE: PLEASE CITE ORIGINAL REFERENCE WHEN USING THIS DATA!!!!!


NAME OF DATA SET: 
Southern South America Multiproxy 1100 Year Temperature Reconstructions 

LAST UPDATE: 3/2010 (Original receipt by WDC Paleo) 
CONTRIBUTORS:  
Neukom, R., J. Luterbacher, R. Villalba, M. Küttel, D. Frank, 
P.D. Jones, M. Grosjean, H. Wanner, J.-C. Aravena, D.E. Black, 
D.A. Christie, R. D'Arrigo, A. Lara, M. Morales, C. Soliz-Gamboa, 
A. Srur, R. Urrutia, and L. von Gunten. 

IGBP PAGES/WDCA CONTRIBUTION SERIES NUMBER: 2010-031  

WDC PALEO CONTRIBUTION SERIES CITATION: 
Neukom, R., et al. 2010. 
Southern South America Multiproxy 1100 Year Temperature Reconstructions. 
IGBP PAGES/World Data Center for Paleoclimatology 
Data Contribution Series # 2010-031. 
NOAA/NCDC Paleoclimatology Program, Boulder CO, USA. 


ORIGINAL REFERENCE: 
Neukom, R., J. Luterbacher, R. Villalba, M. Küttel, D. Frank, 
P.D. Jones, M. Grosjean, H. Wanner, J.-C. Aravena, D.E. Black, 
D.A. Christie, R. D'Arrigo, A. Lara, M. Morales, C. Soliz-Gamboa, 
A. Srur, R. Urrutia, and L. von Gunten. 2010.
Multiproxy summer and winter surface air temperature field 
reconstructions for southern South America covering the past centuries. 
Climate Dynamics, Online First March 28, 2010, 
DOI: 10.1007/s00382-010-0793-3

ABSTRACT: 
We statistically reconstruct austral summer (winter) surface air 
temperature fields back to ad 900 (1706) using 22 (20) annually 
resolved predictors from natural and human archives from southern 
South America (SSA). This represents the first regional-scale 
climate field reconstruction for parts of the Southern Hemisphere 
at this high temporal resolution. We apply three different 
reconstruction techniques: multivariate principal component 
regression, composite plus scaling, and regularized expectation 
maximization. There is generally good agreement between the results 
of the three methods on interannual and decadal timescales. 
The field reconstructions allow us to describe differences 
and similarities in the temperature evolution of different 
sub-regions of SSA. The reconstructed SSA mean summer temperatures 
between 900 and 1350 are mostly above the 1901–1995 climatology. 
After 1350, we reconstruct a sharp transition to colder conditions, 
which last until approximately 1700. The summers in the eighteenth 
century are relatively warm with a subsequent cold relapse peaking 
around 1850. In the twentieth century, summer temperatures reach 
conditions similar to earlier warm periods. The winter temperatures 
in the eighteenth and nineteenth centuries were mostly below the 
twentieth century average. The uncertainties of our reconstructions 
are generally largest in the eastern lowlands of SSA, where the 
coverage with proxy data is poorest. Verifications with independent 
summer temperature proxies and instrumental measurements suggest 
that the interannual and multi-decadal variations of SSA temperatures 
are well captured by our reconstructions. This new dataset can be 
used for data/model comparison and data assimilation as well as 
for detection and attribution studies at sub-continental scales. 


GEOGRAPHIC REGION: Southern South America
PERIOD OF RECORD: 900 - 1995 AD  
  
FUNDING SOURCES:
RN is supported by the by the Swiss NSF through the NCCR Climate. 
JL acknowledges support from the EU/FP7 project ACQWA (grant 212250).



DESCRIPTION: 
This dataset contains the austral summer (DJF) and winter (JJA) 
surface temmperature reconstructions for southern South America (SSA) 
as presented in Neukom et al. 2010.  The data are based on the 
PCR reconstruction (details see paper) and cover the following periods:
Summer: 900-1995
Winter: 1706-1995


We provide the spatial mean as well as spatially explicit datasets.

Files for the SSA Means:
Summer: SSA-Mean_Rekon_DJF_900-1995.txt
Winter: SSA-Mean_Recon_JJA_1706-1995.txt

The Files contain the following columns: 
Years, SSA-Mean temperature anomalies wrt 1901-1995 [°C], 
2SE uncertainties lower bound [°C], 2SE uncertainties upper bound [°C]

The spatial reconstructions are provided in 0.5°x0.5° resolution 
and in NetCDF and text format:
Summer: SSA_Rekon_DJF_900-1995.nc and SSA_Rekon_DJF_900-1995.txt
Winter: SSA_Rekon_JJA_1706-1995.nc and SSA_Rekon_JJA_1706-1995.txt
The text file contain the following columns: 
Year, Temperature anomalies wrt 1931-1995 [°C] of grid-cell 1, 
Temperature anomalies of grid-cell 2, ... , Temperature anomalies 
of grid-cell 9191 

The grid cells are structured as follows:
There are 9191 cells representing 101 longitudes (80.25°W to 30.25°W) 
and 91 latitudes (64.75°S to 19.75°S) 

Cell 1 represents the southwestern corner of the area (80.25°W,64.75°S)
Cell 2 represents the next cell eastward of cell 1 (79.75°W,64.75°S)
...
Cell 101 represent the southeastern corner of the area (30.25°W,64.75°S)
Cell 102 represents the coordinates (80.25°W,64.25°S)
...
Cell 9191 represents the northeastern corner of the area (30.25°W,19.75°S)
Only the land-gridcells (2358 cells) contain data, all other cells have 
"NA" values.