# 
#----------------------------------------------------------------------- 
#               World Data Center for Paleoclimatology, Boulder 
#                                  and 
#                     NOAA Paleoclimatology Program 
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# NOTE: Please cite original publication, online resource and date accessed when using these data, 
# If there is no publication information, please cite investigator, title, online resource and date accessed.
#
# Online_Resource: http://hurricane.ncdc.noaa.gov/pls/paleox/f?p=519:1:::::P1_STUDY_ID:16559
#
# Original_Source_URL: ftp://ftp.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/thornalley2013-cop/thornalley2013-cop-10-1p.txt
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# Archive: Paleoceanography  
#--------------------
# Contribution_Date
#	Date: 2014-06-06
#--------------------
# Title
#	Study_Name: Iceland Basin Sortable Silt Data During the Holocene
#--------------------
# Investigators
#	Investigators: Thornalley, D.J.R.; Blaschek, M.; Davies, F.J.; Praetorius, S.; Oppo, D.W.; McManus, J.F.; Hall, I.R.; Kleiven, H.; Renssen., H.; McCave, I.N.
#--------------------
# Description_and_Notes
#   Description:
#
#--------------------
# Publication
#	Authors: Thornalley, D.J.R., Blaschek, M., Davies, F.J., Praetorius, S., Oppo, D.W., McManus, J.F., Hall, I.R., Kleiven, H., Renssen., H. and McCave, I.N.
#   Published_Date_or_Year: 2013
#	Published_Title: Long-term variations in Iceland-Scotland overflow strength during the Holocene
#	Journal_Name: Climate of the Past 
#	Volume: 9
#	Issue:
#	Pages: 2073-2084
#	DOI: 10.5194/cp-9-2073-2013
#	Abstract: The overflow of deep water from the Nordic seas into the North Atlantic plays a critical role in global ocean circulation and climate. Approximately half of this overflow occurs via the Iceland–Scotland (I–S) overflow, yet the history of its strength throughout the Holocene (~ 0–11 700 yr ago, ka) is poorly constrained, with previous studies presenting apparently contradictory evidence regarding its long-term variability. Here, we provide a comprehensive reconstruction of I–S overflow strength throughout the Holocene using sediment grain size data from a depth transect of 13 cores from the Iceland Basin. Our data are consistent with the hypothesis that the main axis of the I–S overflow on the Iceland slope was shallower during the early Holocene, deepening to its present depth by ~ 7 ka. Our results also reveal weaker I–S overflow during the early and late Holocene, with maximum overflow strength occurring at ~ 7 ka, the time of a regional climate thermal maximum. Climate model simulations suggest a shoaling of deep convection in the Nordic seas during the early and late Holocene, consistent with our evidence for weaker I–S overflow during these intervals. Whereas the reduction in I–S overflow strength during the early Holocene likely resulted from melting remnant glacial ice sheets, the decline throughout the last 7000 yr was caused by an orbitally induced increase in the amount of Arctic sea ice entering the Nordic seas. Although the flux of Arctic sea ice to the Nordic seas is expected to decrease throughout the next century, model simulations predict that under high emissions scenarios, competing effects, such as warmer sea surface temperatures in the Nordic seas, will result in reduced deep convection, likely driving a weaker I–S overflow.
#
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# Funding_Agency 
# 	Funding_Agency_Name:
#      	Grant:
#---------------------
# Site_Information 
#   Site_Name: RAPiD-10-1P
#	Location: North Atlantic Ocean
#	Country: 
#	Northernmost_Latitude: 62.9755
# 	Southernmost_Latitude: 62.9755
# 	Easternmost_Longitude: -17.5895
# 	Westernmost_Longitude: -17.5895
# 	Elevation: -1240
#------------------   
# Data_Collection  
#	Collection_Name: RAPiD-10-1P Sortable Silt T13-cop
#	Earliest_Year: 12023	
#	Most_Recent_Year: 0
#	Time_Unit: cal yr BP
#	Core_Length: 
#	Notes: Core average Sortable Silt (SS): 21.16 um
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# Chronology:
#
# 
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# Variables
# 
# Data line variables format:  one variable per line, shortname- 9 components: what, material, error, units, seasonality, archive, detail, method, C or N for Character or Numeric data) 
# Data line format: tab-delimited text, variable short name as header
## age_calkaBP	age,,,calendar kyr before 1950AD,,,,,N
## SS	sortable silt mean grain size,,,µm,,paleoceanography,,,N
## SS-cent	sortable silt mean grain size,,,µm,,paleoceanography,centered around core mean,,N
#-----------------
# Data:
# Missing Value: NaN
age_calkaBP	SS	SS-cent
0.000	20.43	-0.73
0.475	20.10	-1.06
0.950	20.35	-0.81
2.203	20.80	-0.36
3.456	20.77	-0.39
4.709	19.40	-1.76
5.900	20.60	-0.56
7.215	20.50	-0.66
8.468	20.70	-0.46
9.721	21.76	0.60
10.556	22.56	1.40
10.973	23.01	1.85
11.390	24.15	2.99
11.826	21.51	0.35
12.023	21.20	0.04