# Polar Ice Core 28,000 Year Nitrous Oxide Isotope Data
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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. 
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# Online_Resource: https://www.ncdc.noaa.gov/paleo/study/28890 
#       Description: NOAA Landing Page
# Online_Resource: https://www1.ncdc.noaa.gov/pub/data/paleo/icecore/fischer2019taldice-n2o.txt
#       Description: NOAA location of the template
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# Original_Source_URL:  
#       Description:
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# Description/Documentation lines begin with #
# Data lines have no #
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# Archive: Ice core
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# Dataset DOI: 
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# Parameter_Keywords: atmospheric gas, nitrogen isotopes, oxygen isotopes
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# Contribution_Date
#    Date: 2020-01-24
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# File_Last_Modified_Date
#    Date: 2020-01-24
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# Title
#    Study_Name: Polar Ice Core 28,000 Year Nitrous Oxide Isotope Data
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# Investigators
#      Investigators: Fischer, H.; Schmitt, J.; Bock, M.; Seth, B.; Joos, F.; Spahni, R.; Lienert, S.; Battaglia, G.; Stocker, B.D.; Schilt, A.; Brook, E.J.
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# Description_Notes_and_Keywords
#        Description: Polar ice core nitrous oxide concentration and isotope (d15N and d18O) data of N2O from the TALDICE, EDML, and NGRIP cores, for the past 28,000 years, plus derived emission fluxes. 
#         Provided Keywords: nitrous oxide, ice core, stable isotopes, reconstruction of emissions
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# Publication
# Authors: Hubertus Fischer, Jochen Schmitt, Michael Bock, Barbara Seth, Fortunat Joos, Renato Spahni,Sebastian Lienert, Gianna Battaglia, Benjamin D. Stocker, Adrian Schilt, and Edward J. Brook
# Published_Date_or_Year: 2019-10-15
# Published_Title: N2O changes from the Last Glacial Maximum to the preindustrial – Part 1: Quantitative reconstruction of terrestrial and marine emissions using N2O stable isotopes in ice cores
# Journal_Name: Biogeosciences
# Volume: 16
# Edition: 
# Issue: 20
# Pages: 3997-4021
# Report Number: 
# DOI: 10.5194/bg-16-3997-2019
# Online_Resource: https://doi.org/10.5194/bg-16-3997-2019
# Full_Citation: 
# Abstract: Using high-precision and centennial-resolution ice core information on atmospheric nitrous oxide concentrations and its stable nitrogen and oxygen isotopic composition, we quantitatively reconstruct changes in the terrestrial and marine N2O emissions over the last 21 000 years. Our reconstruction indicates that N2O emissions from land and ocean increased over the deglaciation largely in parallel by 1.7±0.3 and 0.7±0.3 TgN yr-1, respectively, relative to the Last Glacial Maximum level. However, during the abrupt Northern Hemisphere warmings at the onset of the Bolling-Allerod warming and the end of the Younger Dryas, terrestrial emissions respond more rapidly to the northward shift in the Intertropical Convergence Zone connected to the resumption of the Atlantic Meridional Overturning Circulation. About 90 % of these large step increases were realized within 2 centuries at maximum. In contrast, marine emissions start to slowly increase already many centuries before the rapid warmings, possibly connected to a re-equilibration of subsurface oxygen in response to previous changes. Marine emissions decreased, concomitantly with changes in atmospheric CO2 and d13C(CO2), at the onset of the termination and remained minimal during the early phase of Heinrich Stadial 1. During the early Holocene a slow decline in marine N2O emission of 0.4 TgN yr-1 is reconstructed, which suggests an improvement of subsurface water ventilation in line with slowly increasing Atlantic overturning circulation. In the second half of the Holocene total emissions remain on a relatively constant level, but with significant millennial variability. The latter is still difficult to attribute to marine or terrestrial sources. Our N2O emission records provide important quantitative benchmarks for ocean and terrestrial nitrogen cycle models to study the influence of climate on nitrogen turnover on timescales from several decades to glacial-interglacial changes.
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# Funding_Agency
#    Funding_Agency_Name: Swiss National Science Foundation
#    Grant: 200020_172506 and 200020_172476
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# Funding_Agency
#    Funding_Agency_Name: European Research Council Seventh Framework Programme (FP/2007-2013)/ERC Advanced
#    Grant: Grant Agreement no. 226172 (MATRICs) awarded to HF
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# Site_Information 
#	Site_Name: TALDICE
#	Location: Antarctica
#	Country: 
#	Northernmost_Latitude: -72.82
# 	Southernmost_Latitude: -72.82
# 	Easternmost_Longitude: 159.18
# 	Westernmost_Longitude: 159.18
# 	Elevation: 2315 m
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# Data_Collection
#   Collection_Name: Fischer2019TALDICE
#   First_Year: 26695
#   Last_Year: 213
#   Time_Unit: cal yr BP
#   Core_Length: 
#   Notes: 
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# Chronology_Information 
# Chronology: 
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# Variables
# 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)
#
## depth_m	depth,ice,,meter,,ice core,,,N,depth mid sample - TALDICE ice core
## age_kyr_BP	age,gas,,kyr BP,,ice core,,,N,
## N2O_ppb	nitrous oxide,air,,parts per billion,,ice core,,isotope ratio mass spectrometry,N,bulk atmosphere
## N2O_error	nitrous oxide,air,one standard deviation,parts per billion,,ice core,,isotope ratio mass spectrometry,N,
## delta_15N_N2O	delta 15N,nitrous oxide,,per mil N2,,ice core,,isotope ratio mass spectrometry,N,
## delta_15N_N2O_error	delta 15N,nitrous oxide,one standard deviation,per mil N2,,ice core,,isotope ratio mass spectrometry,N,
## delta_18O_N2O	delta 18O,nitrous oxide,,per mil VSMOW,,ice core,,isotope ratio mass spectrometry,N,
## delta_18O_N2O_error	delta 18O,nitrous oxide,one standard deviation,per mil VSMOW,,ice core,,isotope ratio mass spectrometry,N,
## method_code	method,ice,,,,icecore,,,N,method code note
#
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# Data
# Data lines follow (have no #)
# Data line format - tab-delimited text, variable short name as header
# Missing Value: 
depth_m	age_kyr_BP	N2O_ppb	N2O_error	delta_15N_N2O	delta_d15N_error	delta_18O_N2O	delta18O_error	method_code
91.31	0.213	272.9	2.5	9.19	0.30	45.32	0.40	1
101.03	0.319	266.9	2.5	9.63	0.30	46.99	0.40	1
101.42	0.323	267.3	2.5	8.97	0.30	45.70	0.40	1
132.06	0.723	265.7	2.5	9.27	0.30	45.92	0.40	1
192.03	1.497	259.8	2.5	9.68	0.30	45.22	0.40	1
216.18	1.851	260.7	2.5	9.85	0.30	45.74	0.40	1
216.30	1.854	264.8	2.5	9.82	0.30	45.51	0.40	1
227.03	1.987	265.8	2.5	9.61	0.30	44.37	0.40	1
240.42	2.201	269.8	2.5	9.56	0.30	45.57	0.40	1
253.03	2.372	268.2	2.5	9.40	0.30	46.07	0.40	1
264.09	2.533	264.6	2.5	10.10	0.30	45.29	0.40	1
264.40	2.545	269.9	2.5	9.42	0.30	45.80	0.40	1
300.03	3.125	269.9	2.5	9.85	0.30	45.69	0.40	1
348.06	3.893	264.5	2.5	9.54	0.30	44.64	0.40	1
348.37	3.911	268.0	2.5	9.82	0.30	45.27	0.40	1
385.03	4.607	267.1	2.5	9.84	0.30	44.66	0.40	1
409.03	5.065	263.8	2.5	9.48	0.30	44.52	0.40	1
433.03	5.543	265.6	2.5	9.10	0.30	44.89	0.40	1
456.43	6.012	259.7	2.5	9.26	0.30	44.01	0.40	1
486.00	6.634	256.1	2.5	9.43	0.30	45.37	0.40	1
512.00	7.214	260.9	2.5	10.01	0.30	45.55	0.40	1
534.36	7.749	259.6	2.5	9.77	0.30	44.53	0.40	1
534.48	7.754	260.5	2.5	9.47	0.30	44.68	0.40	1
562.48	8.465	256.2	2.5	10.11	0.30	44.34	0.40	1
587.48	9.108	261.9	2.5	10.01	0.30	45.44	0.40	1
646.48	10.407	271.1	2.5	10.64	0.30	46.42	0.40	1
660.27	10.712	267.8	2.5	10.80	0.30	45.72	0.40	1
673.64	11.047	271.0	2.5	10.23	0.30	45.42	0.40	1
681.85	11.293	265.2	2.5	9.88	0.30	45.28	0.40	1
697.79	11.710	245.0	2.5	10.53	0.30	46.18	0.40	1
705.64	11.861	245.4	2.5	10.52	0.30	45.95	0.40	1
769.85	14.230	252.9	2.5	11.17	0.30	46.66	0.40	1
785.69	14.694	222.9	2.5	10.55	0.30	45.42	0.40	1
806.40	15.652	203.5	3.3	10.93	0.30	44.87	0.40	1
806.52	15.659	201.7	3.3	10.39	0.30	44.01	0.40	1
815.45	16.084	201.6	3.3	10.38	0.30	44.63	0.40	1
824.43	16.597	198.9	3.3	10.42	0.30	43.00	0.40	1
824.55	16.604	198.1	3.3	10.66	0.30	44.37	0.40	1
826.12	16.695	200.2	3.3	10.04	0.30	43.02	0.40	1
826.24	16.702	202.0	2.5	10.20	0.30	43.69	0.40	1
839.40	17.523	213.1	3.3	11.32	0.30	45.45	0.40	1
839.52	17.531	213.2	3.3	11.33	0.30	44.99	0.40	1
841.04	17.633	216.6	3.3	11.20	0.30	45.54	0.40	1
847.58	18.118	212.7	2.5	10.74	0.30	45.60	0.40	1
847.71	18.128	210.6	3.3	10.75	0.30	45.20	0.40	1
847.83	18.137	212.1	3.3	10.76	0.30	46.50	0.40	1
848.64	18.202	213.5	3.3	10.91	0.30	45.23	0.40	1
848.76	18.212	221.0	2.5	9.75	0.30	43.85	0.40	1
854.00	18.757	212.7	2.5	10.69	0.30	45.34	0.40	1
856.60	18.951	216.2	2.5	10.15	0.30	45.27	0.40	1
864.60	19.559	220.5	2.5	10.95	0.30	45.86	0.40	1
864.73	19.570	211.9	3.3	10.52	0.30	45.10	0.40	1
864.85	19.580	224.5	3.3	10.62	0.30	44.65	0.40	1
865.60	19.640	214.2	2.5	10.70	0.30	46.39	0.40	1
869.40	19.959	212.7	2.5	11.46	0.30	45.07	0.40	1
873.60	20.346	212.5	2.5	11.15	0.30	44.62	0.40	1
879.40	20.936	210.4	2.5	9.97	0.30	42.96	0.40	1
879.53	20.950	211.7	2.5	11.26	0.30	44.39	0.40	1
887.45	21.829	210.2	2.5	11.44	0.30	44.30	0.40	1
894.84	22.647	214.3	2.5	10.70	0.30	44.55	0.40	1
896.84	22.851	212.5	2.5	10.28	0.30	44.91	0.40	1
903.41	23.613	195.4	2.5	11.07	0.30	45.22	0.40	1
929.60	26.695	221.1	2.5	11.51	0.30	45.85	0.40	1