# 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/lund2013-13pc-dd14c.txt
#       Description: NOAA location of the template
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# Original_Source_URL:  
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# Description/Documentation lines begin with #
# Data lines have no #
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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: W8709A-13PC
#	Location: Ocean>Pacific Ocean>North Pacific Ocean
#	Country:  
#	Northernmost_Latitude: 42.1
# 	Southernmost_Latitude: 42.1
# 	Easternmost_Longitude: -125.8
# 	Westernmost_Longitude: -125.8
# 	Elevation: -2710 m
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# Data_Collection   
#	Collection_Name: Lund2013-13PC-DD14C
#	Earliest_Year: 23950
#	Most_Recent_Year: 1400
#	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,
## DD14C	Delta D14C, , , 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	DD14C
1.400	6.057
9.688	23.721
10.254	22.313
10.563	5.398
11.166	10.455
11.349	18.918
11.806	54.596
11.899	85.550
12.881	64.625
12.763	80.491
13.362	40.231
13.656	16.910
13.341	64.781
14.134	20.631
14.509	76.449
14.962	107.298
15.231	108.916
15.606	140.374
15.704	113.538
16.986	39.832
17.056	74.224
17.655	112.715
17.628	58.022
17.625	91.883
18.217	53.763
18.374	80.429
18.547	108.119
19.035	62.072
19.424	6.300
19.557	13.446
20.511	53.054
20.746	75.692
21.902	15.101
23.950	124.136