# Northeastern USA Little Ice Age Temperature and Precipitation Reconstructions #----------------------------------------------------------------------- # World Data Service for Paleoclimatology, Boulder # and # NOAA Paleoclimatology Program # National Centers for Environmental Information (NCEI) #----------------------------------------------------------------------- # Template Version 2.0 # 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. # # Online_Resource: https://www.ncdc.noaa.gov/paleo/study/6221 # Online_Resource: http://www1.ncdc.noaa.gov/pub/data/paleo/pollen/recons/liadata.txt # Online_Resource: http://www1.ncdc.noaa.gov/pub/data/paleo/pollen/recons/clouds1988.txt # # Original_Source_URL: # # Description/Documentation lines begin with # # Data lines have no # # # Archive: Climate Reconstructions # # Parameter_Keywords: air temperature, precipitation #-------------------- # Contribution_Date # Date: 1993-01-04 #-------------------- # Title # Study_Name: Northeastern USA Little Ice Age Temperature and Precipitation Reconstructions #-------------------- # Investigators # Investigators: Gajewski, K. #-------------------- # Description_and_Notes # Description: Mean summer (JJA) temperatures and total annual precipitation for the past 2000 years # reconstructed from pollen from lakes with laminated sediments. The laminations ensure a more precise # time control than normally obtained from radiocarbon. #-------------------- # Publication # Authors: K. Gajewski # Published_Date_or_Year: 1988-05-01 # Published_Title: Late holocene climate changes in eastern North America estimated from pollen data # Journal_Name: Quaternary Research # Volume: 29 # Edition: # Issue: 3 # Pages: 255-262 # Report_Number: # DOI: 10.1016/0033-5894(88)90034-8 # Online_Resource: http://www.sciencedirect.com/science/article/pii/0033589488900348 # Full_Citation: # Abstract: Well-dated pollen profiles from six sites from Maine to Minnesota record vegetation changes indicative of summer temperature and annual precipitation variations over the past 2000 yr. Laminations in the sediment provide accurate time control. Multiple regression techniques were used to calculate calibration functions from a spatial network of modern pollen and climate data. When applied to the six pollen diagrams, these calibration functions yielded estimates that show a long-term trend toward lower summer temperature. Superimposed on this long-term trend are short-term fluctuations that are frequently in phase at the sites. Departures from the long-term cooling trend are positive around 1500 yr ago (indicating relative warmth) and negative between 200 and 500 yr ago (indicating relative cold). Annual precipitation showed a slight increase at several sites during the past 1000 yr relative to the previous 1000 yr. #------------------ # Publication # Authors: K. Gajewski # Published_Date_or_Year: 1987-01-01 # Published_Title: Climatic impacts on the vegetation of eastern North America during the past 2000 years # Journal_Name: Plant Ecology (formerly Vegetatio) # Volume: 68 # Edition: # Issue: 3 # Pages: 179-190 # Report_Number: # DOI: 10.1007/BF00114719 # Online_Resource: http://link.springer.com/article/10.1007/BF00114719 # Full_Citation: # Abstract: Pollen diagrams from seven lakes with annually laminated sediments sampled at 40-year intervals are analyzed to isolate the climatic effects from other effects on the long-term dynamics of vegetation during the past 1000-2000 years along a transect from Maine to Minnesota. Principal components analysis is used to reduce the dimensionality of the pollen data. The pollen records from all lakes show long-term trends, medium frequency oscillations, and higher frequency fluctuations. The long-term trend is associated with the neoglacial expansion of the boreal forest. The mechanism causing this replacement is a change in frequency of air masses in the area. The medium-frequency oscillations are also associated with climate changes, the most recent of which is the 'Little Ice Age'. The climate-related mechanism causing the medium-frequency changes may be changes in disturbance frequency. The higher frequency fluctuations may also be related to disturbance. This analysis of pollen diagrams into time scales of variation has enabled the separation of climate from other factors affecting vegetation dynamics. By comparing the principal components across a transect of sites it proved possible to interpret the climatic effects on vegetation at most sites and not only at range boundaries and 'sensitive' sites. #------------------ # Funding_Agency # Funding_Agency_Name: US National Science Foundation # Grant: ATM-8219079, ATM-7926039, ATM-7423041 #------------------ # Site_Information # Site_Name: Lake of the Clouds # Location: North America>United States Of America>Minnesota # Country: United States Of America # Northernmost_Latitude: 48.00 # Southernmost_Latitude: 48.00 # Easternmost_Longitude: -91.07 # Westernmost_Longitude: -91.07 # Elevation: 462 m #------------------ # Data_Collection # Collection_Name: Clouds1988LIA # Earliest_Year: 990 # Most_Recent_Year: 10 # Time_Unit: Cal. Year BP # Core_Length: m # Notes: #------------------ # Chronology_Information # Chronology: # #---------------- # Variables # # Data variables follow are preceded by "##" in columns one and two. # Data line variables format: Variables list, one per line, shortname-tab-longname-tab-longname components (9 components: what, material, error, units, seasonality, archive, detail, method, C or N for Character or Numeric data) # ## age_calBP age, , , calendar years before 1975AD, , , , ,N ## temp-JJA surface temperature, , , Deg C, June-July-August, climate reconstructions, , ,N ## precip precipitation, , , mm, annual, climate reconstructions, , ,N # #---------------- # Data: # Data lines follow (have no #) # Data line format - tab-delimited text, variable short name as header # Missing Values: # age_calBP temp-JJA precip 10 17.7 767 20 17.6 757 30 17.6 718 40 17.3 782 50 17.3 791 60 17.6 793 70 17.4 777 80 17.3 823 90 17.4 811 100 17.3 835 110 17.2 810 120 17.2 829 130 17.3 814 140 17.2 813 150 17.3 791 160 17.3 865 170 17.4 853 180 17.6 801 190 17.6 809 200 17.6 766 210 17.5 784 220 17.4 782 230 17.6 863 240 17.5 827 250 17.1 846 260 17.3 841 280 17.4 880 300 17.3 830 320 17.1 842 340 17.4 824 360 17.3 826 370 17.3 839 400 17.1 822 420 17.5 823 440 17.3 810 450 17.3 821 470 17.5 783 480 17.4 774 500 17.4 788 510 17.8 823 530 17.8 784 550 17.8 813 570 17.5 824 580 17.3 782 590 17.2 802 610 17.4 828 630 17.6 786 650 17.4 809 670 17.4 855 690 17.3 796 700 17.4 847 720 17.2 869 740 17.0 798 750 17.3 856 770 17.3 832 790 17.3 835 800 17.2 815 820 17.3 856 840 17.3 847 850 17.2 808 870 17.4 842 890 17.6 831 900 17.6 802 920 17.5 739 930 17.6 857 950 17.3 879 970 17.6 818 990 17.4 777