#-----------------------------------------------------------------------
#                World Data Center for Paleoclimatology, Boulder 
#                                  and 
#                     NOAA Paleoclimatology Program 
#----------------------------------------------------------------------- 

# NOTE: Please cite original reference when using these data,
# plus the Online Resource and date accessed.

# Original_Source_URL: Digitized
# Archive: Historic
#--------------------
# Contribution_Date
# Date: 03-Jan-2015
#--------------------
# Title
# Study_name:  Iceland Historic Ice cover
#--------------------
# Investigators
# Investigators: Bergthórsson, Páll
#--------------------
# Publication
#       Authors: McKay, N.P. and Kaufman, D.S. 
#       Journal_Name: Nature Scientific Data
#       Published Title: An extended Arctic proxy temperature database for the past 2,000 years 
#       Published Date: August 2014 
#       DOI: 10.1038/sdata.2014.26 
#       Abstract: Robust climate reconstructions of the most recent centuries and millennia are invaluable for placing modern warming in the context of natural variability. Here we present an extended and revised database (version 1.1) of proxy temperature records recently used to reconstruct Arctic temperatures for the past 2,000 years. The datasets are presented in a machine-readable format, and have been extended with the geochronologic data and consistently generated time-uncertain ensembles, which will be useful in future analyses of the influence of geochronologic uncertainty. A revised reconstruction using the included updates and corrections suggests a stronger long-term cooling trend between AD 1 and 1900 than previously reported, although decadal to century variability remains consistent with previous studies. Comparisons with the observational record of temperature suggest that as a whole, the datasets faithfully record temperature variability across the Arctic, especially in northeast Canada and Greenland, where the density of records is highest. 
#--------------------
# Publication
#       Authors: Bergthórsson, Páll 
#       Journal Name: Jökull 
#       Published Title: An Estimate of Drift Ice and Temperature in Iceland in 1000 Years 
#       Published Date: 1969 
#       DOI:  
#       Abstract: A fairly good correlation is found between annual temperature ans the incidence of drift ice in Iceland. This relation is used to estimate the temperature in Iceland in the period 1591—1846. Furthermore, the temperature and ice incidence in the years 1591—1969 (estimated and measured) are found to ve correlated with the frequency of severe years, defined in a special manner. This makes it possible to estimate the temperture and ice incidence in the period 930-1591 A.D. The graphs of temperature and ice seem to be in good accordance with the results of analysis of O18 in glacier ice core at Camp Century, Greenland. 
#--------------------
# Site_Information
#        Site_Name: Iceland
#        Region: Arctic
#        Northernmost Latitude: 64.77
#        Southernmost Latitude: 64.77
#        Easternmost Longitude: -18.37
#        Westernmost Longitude: -18.37
#--------------------
# Data_Collection
#        Collection_Name: Bergthorsson.1969.Iceland
#        Earliest_Year: 945
#        Most_Recent_Year: 1935
#        Time_Unit: AD
#--------------------
# Chronology
#--------------------
# Variables
# Data line variables format:  9 components, and a 10th for climate-sensitive variables: what, material, error, units, seasonality, archive, detail, method, C or N for Character or Numeric data, direction of relation to climate (positive or negative)
## year_AD	 age, , , AD, , ,bottom of sample, ,N 
## temp_C	 Temperature,months of ice,,deg C,Winter,Historic,,linear regression,N,positive
#--------------------
# Data
# Missing_Values: NA
# Age Ensembles archived at Bergthorsson.1969.Iceland_AgeEnsemble.nc 
#year_AD	temp_C	
945	 4.0258
975	 3.3285
1005	 4.0526
1035	 3.7352
1065	 3.4583
1095	 4.2793
1125	 4.7091
1155	 4.2839
1185	 3.4373
1215	 3.2571
1245	 3.3100
1275	 3.0573
1305	 3.1833
1335	 3.2493
1365	 3.3104
1485	 3.3174
1515	 3.3170
1545	 3.2501
1575	 3.3050
1605	 3.0841
1635	 3.1128
1665	 3.4091
1695	 3.0646
1725	 3.3055
1755	 2.9264
1785	 2.9934
1815	 3.0913
1845	 3.3440
1875	 2.9475
1905	 3.2889
1935	 4.3605
