# Northern Hemisphere Holocene Latitudinal Temperature Reconstructions
#----------------------------------------------------------------------- 
#                World Data Service for Paleoclimatology, Boulder 
#                                  and 
#                     NOAA Paleoclimatology Program 
#             National Centers for Environmental Information (NCEI)
#----------------------------------------------------------------------- 
# Template Version 3.0
# Encoding: UTF-8
# NOTE: Please cite Publication, and Online_Resource and date accessed when using these data. 
# If there is no publication information, please cite Investigators, Title, and Online_Resource and date accessed. 
#
# Online_Resource: https://www.ncdc.noaa.gov/paleo/study/25890 
#       Description: NOAA Landing Page
# Online_Resource: https://www1.ncdc.noaa.gov/pub/data/paleo/reconstructions/routson2019/ProxyRecords/hydroclimate/
#       Description: NOAA location of the template
#
# Original_Source_URL:  
#       Description:
# 
# Description/Documentation lines begin with #
# Data lines have no #
#
# Archive: Climate Reconstructions
#
# Dataset DOI: 
#
# Parameter_Keywords: hydroclimate
#--------------------
# Contribution_Date
#	Date: 2019-03-27
#--------------------
# File_Last_Modified_Date
#	Date: 2019-03-27
#--------------------
# Title
#	Study_Name: Northern Hemisphere Holocene Latitudinal Temperature Reconstructions
#--------------------
# Investigators
#	Investigators: Routson, C.C.; McKay, N.P.; Kaufman, D.S.; Erb, M.P.; Goosse, H.; Shuman, B.N.; Rodysill, J.R.; Ault, T.
#--------------------
# Description_Notes_and_Keywords
#	Description: Composite latitude band (10S to 90N) temperature reconstructions for the Northern Hemisphere and tropics for the past 9,900 years, plus underlying proxy records. 
#	Latitudinal temperature composites and proxy data and metadata are in Table S1.  Mid-latitude hydroclimate proxy data and metadata are in Table S2.
#	
#	TableS1.xlsx contains: 
#	1.) metadata for each proxy record used in this analysis (PLEASE CITE ORIGINAL AUTHORS WHEN USING THEIR DATA). 
#	2.) Full references for each proxy record listed in the metadata tab
#	3.) Data presented in Figure 3 including zonal temperature composites, latitudinal temperature gradient calculations, latitudinal insolation gradient, and mid-latitude hydroclimate composite
#	4.) Raw temperature records as used in this study. Tabs/files are labeled by Site.Author.Year. These data include age and temperature reconstruction columns. 
#	    Some of these records were obtained from other syntheses efforts (e.g. Marcott et al., 2013) and the associated data (potentially not the original age model) are included here. 
#	
#	TableS2.xlsx contains: 
#	1.) metadata for each proxy record used in this analysis (PLEASE CITE ORIGINAL AUTHORS WHEN USING THEIR DATA). 
#	2.) Full references for each proxy record listed in the metadata tab
#	3.) Site level hydroclimate records used in this study.  Tabs/files are labeled Site.Author.PubYear. These data include age and hydroclimate reconstruction columns. 
#	    Some of these records were obtained from other syntheses efforts and the associated data (potentially not the original age model) are included here. 
#	    Site names with “*” indicate records that are calibrated in units of mm/yr.
#	
#	Proxy Abreviations: 
#	nitrogen 15 isotopes/argon 40 isotopes (15N/40AR)
#	glycerol dialkyle glycerol tetraethers (GDGT)
#	long chain diol index (LDI)
#	magnesium/calcium (Mg/Ca)
#	tree-ring width (TRW)
#	carbon 13 isotopes (d13C)
#	oxygen 18 isotopes (d18O) 
#	loss on ignition (LOI)
#	strontium/calcium (Sr/Ca)
#	deuterium isotopes of leaf wax (dD)
#	records composed of two or more proxy types (hybrid) 
#
#-------------------- 
# Publication 
#	Authors: Cody C. Routson, Nicholas P. McKay, Darrell S. Kaufman, Michael P. Erb, Hugues Goosse, Bryan N. Shuman, Jessica R. Rodysill, Toby Ault 
#	Published_Date_or_Year: 2019-03-27      
#	Published_Title: Mid-latitude net precipitation decreased with Arctic warming during the Holocene
#	Journal_Name: Nature
#	Volume: 
#	Edition: 
#	Issue: 
#	Pages:
#	Report_Number: 
#	DOI: 10.1038/s41586-019-1060-3
#	Online_Resource: https://www.nature.com/articles/s41586-019-1060-3
#	Full_Citation: 
#	Abstract: The latitudinal temperature gradient between the Equator and the poles influences atmospheric stability, the strength of the jet stream and extratropical cyclones. Recent global warming is weakening the annual surface gradient in the Northern Hemisphere by preferentially warming the high latitudes; however, the implications of these changes for mid-latitude climate remain uncertain. Here we show that a weaker latitudinal temperature gradient - that is, warming of the Arctic with respect to the Equator - during the early to middle part of the Holocene coincided with substantial decreases in mid-latitude net precipitation (precipitation minus evapotranspiration, at 30 N to 50 N). We quantify the evolution of the gradient and of mid-latitude moisture both in a new compilation of Holocene palaeoclimate records spanning from 10 S to 90 N and in an ensemble of mid-Holocene climate model simulations. The observed pattern is consistent with the hypothesis that a weaker temperature gradient led to weaker mid-latitude westerly flow, weaker cyclones and decreased net terrestrial mid-latitude precipitation. Currently, the northern high latitudes are warming at rates nearly double the global average, decreasing the Equator-to-pole temperature gradient to values comparable with those in the early to middle Holocene. If the patterns observed during the Holocene hold for current anthropogenically forced warming, the weaker latitudinal temperature gradient will lead to considerable reductions in mid-latitude water resources.
#------------------
# Funding_Agency 
#	Funding_Agency_Name: Science Foundation Arizona Bisgrove Scholar 
#	Grant: BP 0544-13
#------------------
# Funding_Agency 
#	Funding_Agency_Name: US National Science Foundation 
#	Grant: AGS-1602105, EAR-1347221
#------------------
# Funding_Agency 
#	Funding_Agency_Name: State of Arizona Technology and Research Initiative Fund 
#	Grant: 
#------------------
# Funding_Agency 
#	Funding_Agency_Name: USGS Climate and Land Use Program
#	Grant: 
#------------------
# Site_Information 
#	Site_Name: 
#	Location: 
#	Country:  
#	Northernmost_Latitude: 
# 	Southernmost_Latitude: 
# 	Easternmost_Longitude: 
# 	Westernmost_Longitude: 
# 	Elevation:  
#------------------
# Data_Collection   
#	Collection_Name: 
#	Earliest_Year: 
#	Most_Recent_Year: 
#	Time_Unit: 
#	Core_Length: 
#	Notes: 
#------------------
# Chronology_Information
#	Chronology: 
# 	
#----------------	
# Variables 
#
# Data variables follow are preceded by "##" in columns one and two.
# Data line variables format:  one per line, shortname-tab-variable components (what, material, error, units, seasonality, data type,detail, method, C or N for Character or Numeric data, free text) 
#
#
#----------------
# Data:
# Data lines follow (have no #)
# Data line format - tab-delimited text, variable short name as header
# Missing Values:  
#
depth (m)	age (BP)	pollen (precip mm/yr)
0.028	40	1166
0.199	282	1065
0.501	570	1166
0.583	1143	1166
0.625	1339	1166
0.666	1504	1065
0.707	1669	1065
0.748	1834	1065
0.79	1999	1065
0.839	2198	1130
0.945	2619	1166
1.038	2935	1065
1.086	2996	1065
1.138	3064	1065
1.245	3205	976
1.308	3285	924
1.369	3363	914
1.43	3442	924
1.486	3515	924
1.549	3595	914
1.611	3672	914
1.633	3701	1302
1.678	3758	914
1.722	3815	914
1.767	3873	914
1.811	3930	914
1.855	3987	914
1.9	4044	914
1.989	4269	914
2.03	4381	914
2.13	4651	914
2.21	4794	914
2.29	4893	914
2.37	4993	914
2.426	5063	914
2.508	5315	924
2.745	5457	914
2.785	5506	914