# Hamundarstadhahals and Vatnamyri, Iceland Air Temperature Reconstructions during the Early Holocene
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#                World Data Service for Paleoclimatology, Boulder            
#                                  and            
#                     NOAA Paleoclimatology Program            
#             National Centers for Environmental Information (NCEI)            
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# 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/30654
#     Online_Resource_Description:  NOAA Landing Page
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# Online_Resource: https://www.ncdc.noaa.gov/paleo/study/27330
#     Online_Resource_Description:  NOAA Landing Page for Temperature-12k Database
#
# Online_Resource: https://www.ncei.noaa.gov/pub/data/paleo/reconstructions/climate12k/temperature/version1.0.0/Temp12k_directory_NOAA_files/Hamundarstadhahals.Caseldine.2006.txt
#     Online_Resource_Description:  NOAA location of the template
#
# Online_Resource: https://www.ncei.noaa.gov/pub/data/paleo/reconstructions/climate12k/temperature/version1.0.0/Temp12k_directory_LiPD_files/Hamundarstadhahals.Caseldine.2006.lpd
#     Online_Resource_Description:  Linked Paleo Data (LiPD) formatted file containing metadata and data related to this file, for version 1.0.0 of this dataset.
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# Original_Source_URL: 
# Description/Documentation lines begin with #
# Data lines have no #
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# Data_Type: Climate Reconstructions
# Parameter_Keywords: air temperature
# Dataset_DOI: 
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#------------------
# Contribution_Date
#     Date: 2020-04-15
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# File_Last_Modified_Date
#     Date: 2020-05-16
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# Title
#     Study_Name: Hamundarstadhahals and Vatnamyri, Iceland Air Temperature Reconstructions during the Early Holocene
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# Investigators
#     Investigators: Caseldine, Chris; Langdon, Peter; Holmes, Naomi
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# Description_Notes_and_Keywords
#     Description: This dataset was contributed as part of the Temperature-12k project (https://doi.org/10.25921/4RY2-G808). Data were contributed to the project from the original data generators, who are listed in the Investigator field of this template file. Additional notes regarding the use of these data in the Temperature-12k project can be found in the LiPD file listed as an Online_Resource of this template file.
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# Publication
#     Authors: Caseldine, Chris, Peter Langdon, and Naomi Holmes
#     Published_Date_or_Year: 2006
#     Published_Title: Early Holocene climate variability and the timing and extent of the Holocene Thermal Maximum (HTM) in northern Iceland
#     Journal_Name: Quaternary Science Reviews
#     Volume: 25
#     Edition: 
#     Issue: 17-18
#     Pages: 2314-2331
#     Report: 
#     DOI: 10.1016/j.quascirev.2006.02.003
#     Online_Resource: 
#     Full_Citation: 
#     Abstract: The magnitude and timing of Holocene maximum warmth in the Arctic and sub-Arctic has been the subject of considerable recent interest, particularly in the context of future climate change. Although lying at a crucial location in the North Atlantic close to significant atmospheric and oceanic boundaries, terrestrial Holocene climatic data from Iceland are few and predominantly derive from glacial and palaeoecological evidence. Here we present new datasets from Tröllaskagi, based on chironomid-inferred temperatures (CI-T), using sub-fossil chironomids from the same lake sediments supplemented by pollen data. July air temperatures have been derived using an Icelandic training set, and the data suggest optimal temperatures at sea level up to 1.5 °C above current levels around 8 k cal. yr BP, a time when birch woodland was well developed in Tröllaskagi, but when woodland had still not fully developed in the more isolated NW peninsula. Our data thus suggest that optimal summer warmth did not occur in Iceland until 8 kcal. yr BP at the earliest, possibly lasting until 6.7 kcal. yr BP. The amount of warming for July was therefore at least 1.5 °C, but possibly up to 2–3 °C higher than the 1961–1990 average on the basis of the tree-line data. Comparison with data from elsewhere in adjacent Arctic regions, Greenland and Eastern Arctic Canada show peak warmth to be later in Iceland, and less pronounced. It also appears that there were enhanced temperature gradients during the first half of the Holocene between the two study areas Tröllaskagi and the NW Peninsula and that they influenced patterns of vegetation colonisation, with current spatial temperature patterns only developing as Holocene climate deteriorated after around 6 kcal. yr BP.
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# Publication 
#     Authors: Kaufman, D., N. McKay, C. Routson, M. Erb, B. Davis, O. Heiri, S. Jaccard, J. Tierney, C. Dätwyler, Y. Axford, T. Brussel, O. Cartapanis, B. Chase, A. Dawson, A. de Vernal, S. Engels, L. Jonkers, J. Marsicek, P. Moffa-Sánchez, C. Morrill, A. Orsi, K. Rehfeld, K. Saunders, P. S. Sommer, E. Thomas, M. Tonello, M. Tóth, R. Vachula, A. Andreev, S. Bertrand, B. Biskaborn, M. Bringué, S. Brooks, M. Caniupán, M. Chevalier, L. Cwynar, J. Emile-Geay, J. Fegyveresi, A. Feurdean, W. Finsinger, M-C. Fortin, L. Foster, M. Fox, K. Gajewski, M. Grosjean, S. Hausmann, M. Heinrichs, N. Holmes, B. Ilyashuk, E. Ilyashuk, S. Juggins, D. Khider, K. Koinig, P. Langdon, I. Larocque-Tobler, J. Li, A. Lotter, T. Luoto, A. Mackay, E. Magyari, S. Malevich, B. Mark, J. Massaferro, V. Montade, L. Nazarova, E. Novenko, P. Paril, E. Pearson, M. Peros, R. Pienitz, M. Plóciennik, D. Porinchu, A. Potito, A. Rees, S. Reinemann, S. Roberts, N. Rolland, S. Salonen, A. Self, H. Seppä, S. Shala, J-M. St-Jacques, B. Stenni, L. Syrykh, P. Tarrats, K. Taylor, V. van den Bos, G. Velle, E. Wahl, I. Walker, J. Wilmshurst, E. Zhang, S. Zhilich
#     Published_Date_or_Year: 2020-04-14
#     Published_Title: A global database of Holocene paleotemperature records
#     Journal_Name: Scientific Data
#     Volume: 7
#     Edition: 115
#     Issue: 
#     Pages:
#     Report_Number: 
#     DOI: 10.1038/s41597-020-0445-3 
#     Online_Resource: https://www.nature.com/articles/s41597-020-0445-3
#     Full_Citation: 
#     Abstract: A comprehensive database of paleoclimate records is needed to place recent warming into the longer-term context of natural climate variability. We present a global compilation of quality-controlled, published, temperature-sensitive proxy records extending back 12,000 years through the Holocene. Data were compiled from 679 sites where time series cover at least 4000 years, are resolved at sub-millennial scale (median spacing of 400 years or finer) and have at least one age control point every 3000 years, with cut-off values slackened in data-sparse regions. The data derive from lake sediment (51%), marine sediment (31%), peat (11%), glacier ice (3%), and other natural archives. The database contains 1319 records, including 157 from the Southern Hemisphere. The multi-proxy database comprises paleotemperature time series based on ecological assemblages, as well as biophysical and geochemical indicators that reflect mean annual or seasonal temperatures, as encoded in the database. This database can be used to reconstruct the spatiotemporal evolution of Holocene temperature at global to regional scales, and is publicly available in Linked Paleo Data (LiPD) format.
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# Funding_Agency
#     Funding_Agency_Name: 
#     Grant: 
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# Site_Information
#     Site_Name: Hamundarstadhahals
#     Location: Europe>Northern Europe>Iceland
#     Country: Iceland
#     Northernmost_Latitude: 65.97
#     Southernmost_Latitude: 65.97
#     Easternmost_Longitude: -18.45
#     Westernmost_Longitude: -18.45
#     Elevation: 100
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# Data_Collection
#     Collection_Name: Hamundarstadhahals.Caseldine.2006
#     Earliest_Year: 10738.375
#     Most_Recent_Year: 7686.27
#     Time_Unit: cal yr BP
#     Core_Length: 
#     Notes: 
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# Species
#     Species_Name: 
#     Species_Code: 
#     Common_Name: 
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# Chronology_Information
#     Chronology:
# OriginalDateID	depth_top	depth_bottom	age_type	age	uncertainty_old	uncertainty_young	IncludeYN	AdditionalNotes	
# nan	294.0	294.0	age14C	6289.0	57.0	57.0	Y	Bulk sediment	
# nan	311.0	311.0	age14C	6742.0	69.0	69.0	Y	Bulk sediment	
# nan	371.0	371.0	age14C	7663.0	70.0	70.0	Y	Bulk sediment	
# nan	414.0	414.0	age14C	8162.0	69.0	69.0	Y	Bulk sediment	
# nan	439.0	439.0	age14C	8371.0	56.0	56.0	Y	Bulk sediment	
# nan	476.0	476.0	tephra	8770.0	110.0	110.0	Y	Light tephra (Snaefell)	
# nan	589.0	589.0	age14C	8673.0	56.0	56.0	N	Bulk sediment	
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# Variables        
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# Data variables follow that are preceded by "##" in columns one and two.        
# Variables list, one per line, shortname-tab-longname components (9 components: what, material, error, units, seasonality, archive, detail, method, C or N for Character or Numeric data)
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## age	age,,,calendar year before present,,insect;paleolimnology;climate reconstructions,,,N,
## temperature	surface air temperature,midge assemblage,,degree Celsius,Jul,insect;paleolimnology;climate reconstructions,,,N,Based on 52-lake training set from Iceland; WAPLS
## ReliabIeYN1	notes,,,,,insect;paleolimnology;climate reconstructions,,,C,Data are reliable (Yes or No)
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# Data:        
# Data lines follow (have no #)        
# Data line format - tab-delimited text, variable short name as header
# Missing_Values: nan
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age	temperature	ReliabIeYN1	
7686.27	10.211	Y	
7806.11	11.033	Y	
7955.91	11.148	Y	
8105.71	11.648	Y	
8255.51	9.902	Y	
8345.39	10.578	Y	
8405.31	9.95	Y	
8495.19	9.589	Y	
8555.11	9.195	Y	
8615.03	8.732	Y	
8644.99	9.48	Y	
8674.95	9.404	Y	
8794.79	9.967	Y	
8854.71	10.624	Y	
9019.49	9.136	Y	
9154.31	7.824	Y	
9244.19	8.078	Y	
9364.03	9.19	Y	
9423.95	8.136	Y	
9498.85	7.751	Y	
9558.77	8.99	Y	
9618.69	8.807	Y	
9693.59	7.938	Y	
9783.47	7.645	Y	
9903.31	8.186	Y	
9978.21	7.48	Y	
10336.875	6.233	Y	
10482.875	6.142	Y	
10610.625	6.58	Y	
10738.375	7.262	Y