# Deep Pacific 22,000 Year D14C Data and Projection Ventilation Ages 
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#                World Data Service for Paleoclimatology, Boulder 
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#                     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. 
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# Online_Resource: https://www.ncdc.noaa.gov/paleo/study/25110 
#       Description: NOAA Landing Page
# Online_Resource: https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/lund2013/lund2013-2489-proj-age-err.txt
#       Description: NOAA location of the template
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# Original_Source_URL:  
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# Description/Documentation lines begin with #
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# Archive: Paleoceanography
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# Dataset DOI: 
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# Parameter_Keywords: age control, carbon isotopes
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# Contribution_Date
#	Date: 2018-09-07
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# File_Last_Modified_Date
#	Date: 2018-09-07
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# Title
#	Study_Name: Deep Pacific 22,000 Year D14C Data and Projection Ventilation Ages 
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# Investigators
#	Investigators: Lund, D.C.
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# Description_Notes_and_Keywords
#	Description: Deep Pacific ventilation ages estimated from D14C using revised projection age and TTD-ETD methods on 4 Pacific Ocean sediment cores for the past 22,000 years.
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# Publication 
#	Authors: David C.Lund
#	Published_Date_or_Year: 2013-11-01      
#	Published_Title: Deep Pacific ventilation ages during the last deglaciation: Evaluating the influence of diffusive mixing and source region reservoir age 
#	Journal_Name: Earth and Planetary Science Letters
#	Volume: 381
#	Edition: 
#	Issue: 
#	Pages: 52-62
#	Report_Number: 
#	DOI: 10.1016/j.epsl.2013.08.032
#	Online_Resource: https://www.sciencedirect.com/science/article/pii/S0012821X1300469X
#	Full_Citation: 
#	Abstract: Enhanced ventilation of the deep ocean during the last deglaciation may have caused the rise in atmospheric carbon dioxide that drove Earth's climate from a glacial to interglacial state. Recent results based on the projection age method, however, suggest the ventilation rate of the deep Pacific slowed during the deglaciation, opposite the expected pattern (Lund et al., 2011). Because the projection age method does not account for tracer diffusion (Adkins and Boyle, 1997) it can yield spurious results and therefore requires validation with alternative techniques. Here ventilation ages are determined using the transit-time equilibration-time distribution (TTD-ETD) method which explicitly accounts for diffusive mixing in the ocean interior (DeVries and Primeau, 2010). The overall time history of deep Pacific TTD-ETD and projection ages is very similar; both show a 1000-yr increase in ventilation age during Heinrich Stadial 1 (HS1; 14.5-17.5 kyr BP) and a 500-yr increase during the Younger Dryas (YD). The similarity is due in part to the use of projection age error estimates that take into account uncertainty in both calendar age and benthic 14C age. Centennial-scale offsets between the TTD-ETD and projection ages are due primarily to the different approaches used to estimate surface ocean radiocarbon content. Both the TTD-ETD and projection age results imply that the ventilation rate of the deep Pacific decreased during the deglaciation, opposite the pattern expected if Southern Ocean upwelling and enhanced meridional overturning drove outgassing of CO2 from the abyss. Variations in surface water reservoir age could cause an apparent shift in deep Pacific ventilation age but existing proxy records from the Southern Ocean appear to be inconsistent with such a driver.
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# Funding_Agency 
#	Funding_Agency_Name: University of Michigan
#	Grant: 
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# Site_Information 
#	Site_Name: MD02-2489
#	Location: Ocean>Pacific Ocean>North Pacific Ocean
#	Country:  
#	Northernmost_Latitude: 54.3907
# 	Southernmost_Latitude: 54.3907
# 	Easternmost_Longitude: -148.9213
# 	Westernmost_Longitude: -148.9213
# 	Elevation: -3640 m
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# Data_Collection   
#	Collection_Name: Lund2013-2489-proj-age-err
#	Earliest_Year: 19416
#	Most_Recent_Year: 13291
#	Time_Unit: Cal. Year BP
#	Core_Length: 
#	Notes: 
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# Chronology_Information
#	Chronology: 
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# Variables 
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# 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) 
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## age_calkaBP+	age, , , calendar Kyears before present, , , , ,N,
## age_proj+	Projection age upper, , , years, , , , ,N,
## age_calkaBP-	age, , , calendar Kyears before present, , , , ,N,
## age_proj-	Projection age lower, , , years, , , , ,N,
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# Data:
# Data lines follow (have no #)
# Data line format - tab-delimited text, variable short name as header
# Missing Values:  
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age_calkaBP+	age_proj+	age_calkaBP-	age_proj-
13.291	1902.794	13.803	1367.162
14.164	2854.338	15.208	1808.640
15.098	2957.864	16.255	1748.928
15.863	2482.141	16.789	1464.693
15.953	1433.729	16.903	450.989
16.923	928.307	17.558	287.929
17.178	2287.666	17.842	1594.936
18.557	2043.211	18.985	1441.729
18.903	2338.338	19.416	1689.288