#-----------------------------------------------------------------------
#                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: 13-Jun-2014
#--------------------
# Title
# Study_name: Lake Hampträsk Finland Lake sediment Chironomids
#--------------------
# Investigators
# Investigators: Luoto, Tomi P. and Sarmaja-Korjonen, Kaarina and Nevalainen, Liisa and Kauppila, Tommi
#--------------------
# 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: In review 
#       DOI: TBD 
#       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: Luoto, Tomi P. and Sarmaja-Korjonen, Kaarina and Nevalainen, Liisa and Kauppila, Tommi 
#       Journal Name: The Holocene 
#       Published Title: A 700 year record of temperature and nutrient changes in a small eutrophied lake in southern Finland 
#       Published Date: 2009 
#       DOI: 10.1177/0959683609341002 
#       Abstract: This study aimed to distinguish natural and anthropogenic environmental changes, mainly in climate and nutrient conditions, during the past c. 700 years in Lake Hampträsk, southern Finland. We used sedimentary assemblages of aquatic organisms and physical properties of the sediment as proxies for the past environmental conditions. The results of diatom-inferred phosphorus reconstruction indicated that the lake was already meso-eutrophic at c. AD 1400, possibly because the preceding cultivation of the area had increased the lake’s nutrient condition. Chironomid-inferred temperatures indicated favourable climatic conditions at the end of the ‘Medieval Warm Period’, but the temperatures steadily decreased until a significant drop in the values occurred at c. AD 1700, representing the coldest period of the ‘Little Ice Age’ (LIA) in southern Finland. This cold period was illustrated by major changes in the lake’s ecosystem and physical environment. After the LIA, the chironomid-inferred temperatures increased, as expected in the light of modern observations. However, the diatom-inferred phosphorus showed a decreasing trend, which is in contrast to the measured phosphorus values that imply a currently eutrophic condition. The reason for the underestimation may be the predominance of periphytic taxa that are assigned low TP optima in the inference model. 
#--------------------
# Site_Information
#        Site_Name: Lake Hamptrask
#        Region: Arctic
#        Northernmost Latitude: 60.28
#        Southernmost Latitude: 60.28
#        Easternmost Longitude: 25.42
#        Westernmost Longitude: 25.42
#--------------------
# Data_Collection
#        Collection_Name: Luoto.2009.Lake Hamptrask
#        Earliest_Year: 1359.3
#        Most_Recent_Year: 1993.5
#        Time_Unit: AD
#        Core_Length: 46 (in cm)
#--------------------
# Chronology
          depth_top (mm) | depth_bot (mm) | age14C (bp) | age_error (1s) | age (bp) | depth (mm) | thickness (mm)
          0                5                NA            5                -47        2.5          5
          160              170              104.69        0.3              NA         165          10
          220              230              0             0                NA         225          10
          220              230              605           30               NA         225          10
          290              300              450           120              NA         295          10
          320              330              550           30               NA         325          10
          350              360              340           40               NA         355          10
          440              450              565           30               NA         445          10
#--------------------
# 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,July,Paleolimnology,,,N,positive
#--------------------
# Data
# Missing_Values: NA
# Age Ensembles archived at Luoto.2009.Lake Hamptrask_AgeEnsemble.nc 
#depth_cm	depthUpper_cm	depthLower_cm	year_AD	yearYoung_AD	yearOld_AD	temp_C	
0.5	 0	 1	 1993.50	 2000.2	 1986.8	 16.5
1.5	 1	 2	 1980.20	 1986.8	 1973.6	 15.2
2.5	 2	 3	 1967.00	 1973.6	 1960.4	 15.6
3.5	 3	 4	 1953.80	 1960.4	 1947.2	 15.8
4.5	 4	 5	 1940.60	 1947.2	 1934.0	 15.8
5.5	 5	 6	 1926.90	 1934.0	 1919.8	 16.4
6.5	 6	 7	 1912.70	 1919.8	 1905.6	 16.0
7.5	 7	 8	 1898.45	 1905.6	 1891.3	 16.3
8.5	 8	 9	 1884.20	 1891.3	 1877.1	 15.8
9.5	 9	 10	 1870.00	 1877.1	 1862.9	 15.9
10.5	 10	 11	 1855.85	 1862.9	 1848.8	 15.6
11.5	 11	 12	 1841.75	 1848.8	 1834.7	 16.3
12.5	 12	 13	 1827.70	 1834.7	 1820.7	 15.8
13.5	 13	 14	 1813.75	 1820.7	 1806.8	 15.7
14.5	 14	 15	 1799.95	 1806.8	 1793.1	 14.7
15.5	 15	 16	 1786.05	 1793.1	 1779.0	 15.2
16.5	 16	 17	 1771.95	 1779.0	 1764.9	 15.6
17.5	 17	 18	 1757.90	 1764.9	 1750.9	 14.7
18.5	 18	 19	 1743.90	 1750.9	 1736.9	 14.2
19.5	 19	 20	 1730.00	 1736.9	 1723.1	 14.5
20.5	 20	 21	 1716.00	 1723.1	 1708.9	 12.8
21.5	 21	 22	 1701.70	 1708.9	 1694.5	 13.2
22.5	 22	 23	 1687.30	 1694.5	 1680.1	 13.9
23.5	 23	 24	 1672.90	 1680.1	 1665.7	 13.4
24.5	 24	 25	 1658.70	 1665.7	 1651.7	 15.1
25.5	 25	 26	 1644.65	 1651.7	 1637.6	 15.2
26.5	 26	 27	 1630.55	 1637.6	 1623.5	 14.4
27.5	 27	 28	 1616.50	 1623.5	 1609.5	 15.2
28.5	 28	 29	 1602.45	 1609.5	 1595.4	 15.0
29.5	 29	 30	 1588.45	 1595.4	 1581.5	 15.0
30.5	 30	 31	 1575.15	 1581.5	 1568.8	 14.8
31.5	 31	 32	 1562.40	 1568.8	 1556.0	 14.9
32.5	 32	 33	 1549.55	 1556.0	 1543.1	 15.3
33.5	 33	 34	 1536.60	 1543.1	 1530.1	 15.1
34.5	 34	 35	 1523.75	 1530.1	 1517.4	 15.7
35.5	 35	 36	 1510.95	 1517.4	 1504.5	 15.9
36.5	 36	 37	 1498.00	 1504.5	 1491.5	 15.4
37.5	 37	 38	 1484.85	 1491.5	 1478.2	 14.9
38.5	 38	 39	 1471.45	 1478.2	 1464.7	 15.5
39.5	 39	 40	 1458.15	 1464.7	 1451.6	 15.6
40.5	 40	 41	 1444.30	 1451.6	 1437.0	 15.4
41.5	 41	 42	 1429.65	 1437.0	 1422.3	 15.9
42.5	 42	 43	 1414.95	 1422.3	 1407.6	 16.1
43.5	 43	 44	 1400.30	 1407.6	 1393.0	 14.7
44.5	 44	 45	 1385.80	 1393.0	 1378.6	 15.5
45.5	 45	 46	 1372.15	 1378.6	 1365.7	 16.3
46.5	 46	 47	 1359.30	 1365.7	 1352.9	 16.4
