DOI: 10.25921/5xb4-yb34
title: NOAA/WDS Paleoclimatology - Southern Hemisphere 2000 Year Proxy Correlation Maps

description: This study presents a comprehensive assessment of high-resolution Southern Hemisphere (SH) paleoarchives covering the last 2000 years. We identified 174 monthly to annually resolved climate proxy (tree ring, coral, ice core, documentary, speleothem and sedimentary) records from the Hemisphere. We assess the interannual and decadal sensitivity of each proxy record to large-scale circulation indices from the Pacific, Indian and Southern Ocean regions over the twentieth century. We then analyse the potential of this newly expanded palaeoclimate network to collectively represent predictands (sea surface temperature, sea level pressure, surface air temperature and precipitation) commonly used in climate reconstructions. The key dynamical centres-of-action of the equatorial Indo-Pacific are well captured by the palaeoclimate network, indicating that there is considerable reconstruction potential in this region, particularly in the post AD 1600 period when a number of long coral records are available. Current spatiotemporal gaps in data coverage and regions where significant potential for future proxy collection exists are discussed. We then highlight the need for new and extended records from key dynamical regions of the Southern Hemisphere. Although large-scale climate field reconstructions for the SH are in their infancy, we report that excellent progress in the development of regional proxies now makes plausible estimates of continental- to hemispheric-scale climate variations possible.
description: The folder Correlation_maps contains spatial correlations maps 
for the SH and the following data: 
SH Proxy records Presented in the manuscript (Figure 1 and Tables I-IV) 
and a few additional records that were excluded from the paper because 
they do not match the selection criteria (location, resolution, length). 

Maps for the following instrumental grids are available
- HadISST: HadISST SSTs, 1°x1°, (Rayner et al. 2003, doi:10.1029/2002JD002670 )
- HadSLP2r: HadSLP2r SLP, 5°x5° (Allan and Ansell 2006, Journal of Climate)
- CRU_TS3_RR CRU TS 3.0 land precipitation, 0.5°x0.5° res 
  (updated from Mitchell and Jones 2005, 10.1002/joc.1181)
- CRU_TS3_TT CRU TS 3.0 land surface air temperatures, 0.5°x0.5° res 
  (updated from Mitchell and Jones 2005, 10.1002/joc.1181) 

And also alternatively for the following grids:
- 20RA2_SLP: 20th centruy Reanalysis V2 SLP, 2°x2° resolution 
  (Compo et al. 2011, DOI: 10.1002/qj.776)
- 20RA2_TT:  20th centruy Reanalysis V2 Temperature, 2°x2° resolution 
  (Compo et al. 2011, DOI: 10.1002/qj.776)
- ERSST3b: ERSST3b SSTs, 2°x2° (Smith et al. 2008, 10.1175/2007JCLI2100.1)
- HadCRUT3v: HadCRUT3v Land and Ocean temperatures, 5°x5°, 
  (Brohan et al. 2006, doi:10.1029/2005JD006548)

Further details:
- Maps are also available for filtered (10-year loess filter) data 
  (both proxy and instrumental climate records were filtered). 
  These are the files with the ending "_decadal_10a_loess.png".
- Time period: 1901-2000
- The maps show the correlations with DJFMAM and JJASON averages 
  with the proxy record shifted for  -1, 0 and 1 years, respectively.
- Areas with significant Spearman correlation coefficients 
  with the target field are shaded.  Significance levels are derived 
  based on Monte Carlo simulations of AR(1) noise time series with 
  the same AR(1) properties as the proxy and instrumental climate data.
- also indicated for each map: n.sig=The latitude weighted fraction 
  of cells with significant correlations and r.max=the maximum (absolute) 
  correlation.
- All data were detrended prior to the correlation analysis. If the proxy 
  record has a significant trend in the 20th century this is indicated by 
  a note "Trend in 20th century proxy data!" in the top-right of the plot
- For some sub-annually resolved coral records, maps are provided for the 
  annually averaged (May-April years) as well as summer-autumn (DJFMAM) 
  and winter-spring (JJASON) averaged proxy data.
- For each record there is a file called NAME_time_series_plots.png where 
  the original and the detrended proxy time series as well as the 
  decadally filtered curve are shown. AR(1) coefficients of the proxy 
  records are also indicated here.
  
For further details please refer to the manuscript.