# 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
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# 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-d14c-err.txt
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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-D14C-err
#	Earliest_Year: 19421
#	Most_Recent_Year: 13307
#	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,
## D14C-	Delta 14C lower, , , per mil, ,Paleoceanography,,,N,
## age_calkaBP+	age, , , calendar Kyears before present, , , , ,N,
## D14C+	Delta 14C upper, , , per mil, ,Paleoceanography,,,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-	D14C-	age_calkaBP+	D14C+
13.307	-84.934	13.830	-23.752
14.145	-123.681	15.166	-6.442
15.042	-118.619	16.239	21.850
15.843	-52.792	16.788	66.237
15.906	46.455	16.859	177.163
16.928	130.859	17.558	225.538
17.145	-56.016	17.824	30.571
18.567	-14.242	19.003	47.739
18.925	-14.306	19.421	55.628