#-----------------------------------------------------------------------
#                World Data Center for Paleoclimatology, Boulder 
#                                  and 
#                     NOAA Paleoclimatology Program 
#----------------------------------------------------------------------- 

# NOTE: Please cite original reference when using these data,
# plus the Online Resource and date accessed.

# Original_Source_URL: 
# Archive: Lake sediment
#--------------------
# Contribution_Date
# Date: 03-Jan-2015
#--------------------
# Title
# Study_name: Lake 4 Southampton Island Lake sediment Chironomid
#--------------------
# Investigators
# Investigators: Rolland, Nicolas and Larocque, Isabelle and Francus, Pierre and Pienitz, Reinhard and Laperrière, Laurence
#--------------------
# Publication
#       Authors: McKay, N.P. and Kaufman, D.S. 
#       Journal_Name: Nature Scientific Data
#       Published Title: An extended Arctic proxy temperature database for the past 2,000 years 
#       Published Date: August 2014 
#       DOI: 10.1038/sdata.2014.26 
#       Abstract: Robust climate reconstructions of the most recent centuries and millennia are invaluable for placing modern warming in the context of natural variability. Here we present an extended and revised database (version 1.1) of proxy temperature records recently used to reconstruct Arctic temperatures for the past 2,000 years. The datasets are presented in a machine-readable format, and have been extended with the geochronologic data and consistently generated time-uncertain ensembles, which will be useful in future analyses of the influence of geochronologic uncertainty. A revised reconstruction using the included updates and corrections suggests a stronger long-term cooling trend between AD 1 and 1900 than previously reported, although decadal to century variability remains consistent with previous studies. Comparisons with the observational record of temperature suggest that as a whole, the datasets faithfully record temperature variability across the Arctic, especially in northeast Canada and Greenland, where the density of records is highest. 
#--------------------
# Publication
#       Authors: Rolland, Nicolas and Larocque, Isabelle and Francus, Pierre and Pienitz, Reinhard and Laperrière, Laurence 
#       Journal Name: Quaternary Research 
#       Published Title: Evidence for a warmer period during the 12th and 13th centuries AD from chironomid assemblages in Southampton Island, Nunavut, Canada 
#       Published Date: 2009 
#       DOI: 10.1016/j.yqres.2009.03.001 
#       Abstract: This study presents the Late-Holocene evolution of a northern Southampton Island (Nunavut, Canada) lake, using fossil chironomids supported by sedimentological evidences (XRF, grain size and CNS). All proxies revealed a relatively stable environment during the last millennium with short-lived events driving changes in the entire lake ecosystem. The chironomid-based paleotemperatures revealed variations of significant amplitude coincident with changes in the sediment density and chemical composition of the core. Higher temperature intervals were generally correlated to lower sediment density with higher chironomid concentration and diversity. Higher temperatures were recorded from cal yr AD 1160 to AD 1360, which may correspond to the Medieval Warm Period. Between cal yr AD 1360 and AD 1700, lower temperatures were probably related to a Little Ice Age event. This study presents new information on the timing of known climatic events which will refine our knowledge of the paleoclimate and climatic models of the Foxe Basin region. It also provides a new framework for the evolution of such freshwater ecosystems under the ”Anthropocene„ and underlines the importance of including sedimentological proxies when interpreting chironomid remains as this combined approach provides an extended overview of the past hydrological and geochemical changes and their impacts on lake biota. 
#--------------------
# Site_Information
#        Site_Name: Lake 4
#        Region: Arctic
#        Northernmost Latitude: 65.1
#        Southernmost Latitude: 65.1
#        Easternmost Longitude: -83.79
#        Westernmost Longitude: -83.79
#--------------------
# Data_Collection
#        Collection_Name: Rolland.2009.Lake 4
#        Earliest_Year: 634.05
#        Most_Recent_Year: 1997.5
#        Time_Unit: AD
#        Core_Length: 31 (in cm)
#--------------------
# Chronology
          depth_top (mm) | depth_bot (mm) | depth (mm) | age14C (bp) | age_error (1_s) | age (bp) | depth_mid (mm) | thickness (mm)
          NA               NA               0.6          NA            1                -54        NA               NA
          NA               NA               3            NA            1                -51        NA               NA
          NA               NA               7.1          NA            1                -44        NA               NA
          NA               NA               11.7         NA            1                -34        NA               NA
          NA               NA               19.7         NA            1                -8         NA               NA
          NA               NA               25.5         NA            1                17         NA               NA
          NA               NA               33.5         NA            1                44         NA               NA
          70               75               NA           1995          25                NA         72.5             5
          110              115              NA           2190          25                NA         112.5            5
          170              175              NA           2280          25                NA         172.5            5
          130              140              NA           560           40                NA         135              10
          270              275              NA           1150          40                NA         272.5            5
#--------------------
# Variables
# Data line variables format:  9 components, and a 10th for climate-sensitive variables: what, material, error, units, seasonality, archive, detail, method, C or N for Character or Numeric data, direction of relation to climate (positive or negative)
## depth_cm	 depth, , , cm, , ,middle of sample, ,N 
## depthUpper_cm	 depth, , , cm, , ,top of sample, ,N 
## depthLower_cm	 depth, , , cm, , ,bottom of sample, ,N 
## year_AD	 age, , , AD, , ,middle of sample, Bacon ,N 
## yearYoung_AD	 age, , , AD, , ,top of sample, Bacon ,N 
## yearOld_AD	 age, , , AD, , ,bottom of sample, Bacon ,N 
## temp_C	 Temperature,Chironomid,,deg C,August,Paleolimnology,,,N,positive
#--------------------
# Data
# Missing_Values: NA
# Age Ensembles archived at Rolland.2009.Lake 4_AgeEnsemble.nc 
#depth_cm	depthUpper_cm	depthLower_cm	year_AD	yearYoung_AD	yearOld_AD	temp_C	
0.5	 0	 1	 1997.45	 2005.1	 1989.8	 8.5339
1.5	 1	 2	 1973.85	 1989.8	 1957.9	 9.2569
2.5	 2	 3	 1936.30	 1957.9	 1914.7	 9.1112
3.5	 3	 4	 1901.70	 1914.7	 1888.7	 8.9856
4.5	 4	 5	 1863.40	 1888.7	 1838.1	 8.1604
5.5	 5	 6	 1811.75	 1838.1	 1785.4	 7.7743
6.5	 6	 7	 1759.35	 1785.4	 1733.3	 8.0337
7.5	 7	 8	 1707.00	 1733.3	 1680.7	 8.8266
8.5	 8	 9	 1654.00	 1680.7	 1627.3	 7.4427
9.5	 9	 10	 1600.65	 1627.3	 1574.0	 7.3545
10.5	 10	 11	 1547.95	 1574.0	 1521.9	 8.1981
11.5	 11	 12	 1495.05	 1521.9	 1468.2	 8.2469
12.5	 12	 13	 1441.55	 1468.2	 1414.9	 7.7184
13.5	 13	 14	 1389.70	 1414.9	 1364.5	 9.3805
14.5	 14	 15	 1344.20	 1364.5	 1323.9	 9.4466
15.5	 15	 16	 1304.20	 1323.9	 1284.5	 9.3005
16.5	 16	 17	 1264.60	 1284.5	 1244.7	 8.4877
18.5	 18	 19	 1184.85	 1204.9	 1164.8	 6.5428
19.5	 19	 20	 1145.35	 1164.8	 1125.9	 8.3586
21.5	 21	 22	 1065.70	 1085.5	 1045.9	 8.2618
22.5	 22	 23	 1025.70	 1045.9	 1005.5	 8.2583
23.5	 23	 24	 985.65	 1005.5	 965.8	 8.1458
24.5	 24	 25	 946.45	 965.8	 927.1	 8.5841
25.5	 25	 26	 907.80	 927.1	 888.5	 8.8499
27.5	 27	 28	 829.75	 849.6	 809.9	 8.0562
28.5	 28	 29	 785.70	 809.9	 761.5	 8.7910
29.5	 29	 30	 736.05	 761.5	 710.6	 8.6921
31.5	 31	 32	 634.05	 659.2	 608.9	 6.7229
