# Fennoscandia 7500Yr Pollen-TreeRing July Temperature Reconstructions #---------------------------------------------------- # World Data Service for Paleoclimatology, Boulder # and # NOAA Paleoclimatology Program # National Centers for Environmental Information (NCEI) #---------------------------------------------------- # Template Version 4.0 # Encoding: UTF-8 # NOTE: Please cite original publication, NOAA Landing Page URL, dataset and publication DOIs (where available), and date accessed when using downloaded data. If there is no publication information, please cite investigator, study title, NOAA Landing Page URL, and date accessed. # # Description/Documentation lines begin with # # Data lines have no # # # NOAA_Landing_Page: https://www.ncei.noaa.gov/access/paleo-search/study/13119 # Landing_Page_Description: NOAA Landing Page of this file's parent study, which includes all study metadata. # # Study_Level_JSON_Metadata: https://www.ncei.noaa.gov/pub/data/metadata/published/paleo/json/noaa-lake-13119.json # Study_Level_JSON_Description: JSON metadata of this data file's parent study, which includes all study metadata. # # Data_Type: Paleolimnology # # Dataset_DOI: 10.25921/e3j5-sv40 # # Science_Keywords: PAGES Arctic 2k, Air Temperature Reconstruction, PAGES 2k Network #-------------------- # Resource_Links # # Data_Download_Resource: https://www.ncei.noaa.gov/pub/data/paleo/paleolimnology/europe/fennoscandia2012-svanavatnet-noaa.txt # Data_Download_Description: NOAA Template File; Temperature Reconstruction from Pollen # #-------------------- # Contribution_Date # Date: 2012-06-30 #-------------------- # File_Last_Modified_Date # Date: 2024-06-06 #-------------------- # Title # Study_Name: Fennoscandia 7500Yr Pollen-TreeRing July Temperature Reconstructions #-------------------- # Investigators # Investigators: Helama, S.(https://orcid.org/0000-0002-9777-3354); Seppä, H.T.(https://orcid.org/0000-0003-2494-7955); Bjune, A.E.(https://orcid.org/0000-0002-4509-0148); Birks, H.J.B.(https://orcid.org/0000-0002-5891-9859) #-------------------- # Description_Notes_and_Keywords # Description: Pollen data and temperature reconstructions from 11 lakes in northern Fennoscandia, plus July pollen/tree-ring temperature reconstruction for the past 7500 years. # # Northern Fennoscandia: ~66°-70°N, ~14°-35°E #-------------------- # Publication # Authors: Helama, S., H. Seppä, A.E. Bjune, and H.J.B. Birks # Journal_Name: Journal of Paleolimnology # Published_Title: Fusing pollen-stratigraphic and dendroclimatic proxy data to reconstruct summer temperature variability during the past 7.5 ka in subarctic Fennoscandia # Published_Date_or_Year: 2012 # Volume: 48 # Pages: 275-286 # Issue: 1 # Report_Number: # DOI: 10.1007/s10933-012-9598-1 # Full_Citation: # Abstract: A new palaeoclimatic reconstruction of mid-summer (July) temperatures for the last 7.5 ka in northern Fennoscandia is presented. It is based on two botanical proxies: spectra of fossil pollen and tree rings of Scots pine logs recovered from lacustrine sediments in the Arctic tree-line region. A newly developed method of proxy fusion is used to integrate the proxy-specific reconstructions of past summer temperature variability based on the pollen-stratigraphic and dendroclimatic data. The rationale behind the method is that the two proxies are likely to be connected to climate variability in a timescale-dependent fashion and, accordingly, the new reconstruction makes use of the low- and high-frequencies from pollen-stratigraphic and tree-ring data, respectively. The most prominent features of the new reconstruction are: (1) the long-term decline of temperatures by 2.0°C over the past 7.5 ka, (2) the mid-Holocene warmth culminating between 5 and 4 ka as a deviation from the cooling trend, (3) the Little Ice Age cool phase between 0.7 and 0.1 ka, and (4) the subsequent warming during the past century. These periods are superimposed on year-to-year variations in climate as dated to calendar-year accuracy by dendrochronology. Within the modern period, the years 1934 and 1937 are among the warmest, and the years 1903 and 1910 are among the coldest summers in the context of the past 7.5 ka. On average, the reconstructed Holocene climate was approximately 0.85°C warmer than the twentieth century. #-------------------- # Authors: Helama, S., M. Macias Fauria, K. Mielikäinen, M. Timonen, and M. Eronen # Journal_Name: Geological Society of America Bulletin # Published_Title: Sub-Milankovitch solar forcing of past climates: Mid and late Holocene perspectives # Published_Date_or_Year: 2010 # Volume: 122 # Pages: 1981–1988 # Issue: 11-12 # Report_Number: # DOI: 10.1130/B30088.1 # Full_Citation: # Abstract: A comparison was performed of solar activity and terrestrial temperature records, both derived from tree rings (i.e., without dating uncertainties), with identification of detailed and highly quantified time- and timescale-dependent characteristics of solar forcing on climate through the current interglacial in the context of oceanic variability. The tree-ring–derived temperature record from high latitudes of Europe (Lapland) exhibits persistent annual-to-millennial–scale variations, with multidecadal to multicentennial periodicities reminiscent of the Sun's periodicities. At millennial scales, cool temperatures coincided with large-scale glacial maxima. Moreover, millennial and bimillennial modes of climate variability were correlative with variations in sunspot numbers on similar scales, with near-century and near-zero lags, respectively. Although they were subtle in amplitude, the sub-Milankovitch–scale changes in the reception of the Sun's energy could thus suffice to noticeably modulate interglacial climate variations. The relative significance of timescale-dependent, Sun-climate linkages has likely varied during the mid and late Holocene times, respectively. Thus, the warmer and cooler paleotemperatures during the Medieval Climate Anomaly and Little Ice Age were better explained by solar variations on a millennial rather than bimillennial scale. The observed variations may have occurred in association with internal climate amplification (likely, thermohaline circulation and El Niño–Southern Oscillation activity). The near-centennial delay in climate in responding to sunspots indicates that the Sun's influence on climate arising from the current episode of high sunspot numbers may not yet have manifested itself fully in climate trends. If neglected in climate models, this lag could cause an underestimation of twenty-first–century warming trends. #-------------------- # Funding_Agency # Funding_Agency_Name: # Grant: #-------------------- # Site_Information # Site_Name: Svanåvatnet # Location: Norway # Northernmost_Latitude: 66.42 # Southernmost_Latitude: 66.42 # Easternmost_Longitude: 14.05 # Westernmost_Longitude: 14.05 # Elevation_m: 243 #-------------------- # Data_Collection # Collection_Name: Svanåvatnet-Temp2012 # First_Year: 8750 # Last_Year: -17 # Time_Unit: cal yr BP # Core_Length_m: # Parameter_Keywords: reconstruction # Notes: Original publication Bjune et al. 2004 (doi:10.1080/03009480410001244) and Bjune et al. 2009 (doi:10.1007/s10933-008-9254-y) #-------------------- # Chronology_Information # Chronology: Radiocarbon # Chronology_Download_Resource: https://www.ncei.noaa.gov/pub/data/paleo/templates/noaa-wds-paleo-14c-terms.csv # Chronology_Download_Description: Radiocarbon terms and definitions. # Chronology_Notes: Radiocarbon dates from Bjune et al. 2009 (doi:10.1007/s10933-008-9254-y) # Rejection_Rationale: # Reservoir_Method: nearly all the sites are located on acidic bedrock and there is no evidence for any significant "hard water" effects in the bulk-sediment ages. # Calibration_Method: CALIB4.3 (Stuiver and Reimer 1993) and the INTCAL98 calibration data set (Stuiver et al. 1998). # Age_Model_Method: linear regression # Missing_Values: NaN # Chronology_Table: # lab_code depth_end_cm depth_start_cm age_14C_BP1950 age_14C_1s_yr age_calib_BP1950 material_dated calib_curve # Poz-17479 41 42 1525 30 1409 macrofossils IntCal98 # Poz-17473 68 69 2585 35 2744 macrofossils IntCal98 # Poz-17480 199 200 5850 40 6697 macrofossils IntCal98 # Poz-17482 219 222 6390 40 7300 macrofossils IntCal98 #-------------------- # Variables # PaST_Thesaurus_Download_Resource: https://www.ncei.noaa.gov/access/paleo-search/skos/past-thesaurus.rdf # PaST_Thesaurus_Download_Description: Paleoenvironmental Standard Terms (PaST) Thesaurus terms, definitions, and relationships in SKOS format. # # Data variables follow that are preceded by '##' in columns one and two. # Variables list, one per line, shortname-tab-var components: what, material, error, units, seasonality, data type, detail, method, C or N for Character or Numeric data) # ## depth_cm depth,,,centimeter,,climate reconstructions;pollen,,,N, ## age_calBP age,,,calendar year before present,,climate reconstructions;pollen,,,N, ## T-JULY temperature,,,degree Celsius,Jul,climate reconstructions;pollen,,,N, ## T-JULY-err temperature,,one standard error,degree Celsius,Jul,climate reconstructions;pollen,,,N,Bootstrap estimated SEP #-------------------- # Data: # Data lines follow (have no #) # Data line format - tab-delimited text, variable short name as header # Missing_Values: depth_cm age_calBP T-JULY T-JULY-err 0 -17 10.5593 1.12765 4 149 10.3107 1.15788 8 317 10.9877 1.12901 12 484 9.82986 1.1479 16 650 11.1696 1.12266 20 817 10.6741 1.14682 24 983 11.171 1.1384 28 1148 11.1213 1.13436 32 1312 10.7838 1.13188 36 1476 11.4004 1.13035 40 1639 11.4917 1.15028 44 1800 11.4161 1.11608 48 1960 12.3013 1.13944 52 2119 11.3481 1.13562 56 2277 11.44 1.17305 60 2433 11.9575 1.1109 64 2586 11.2212 1.13929 68 2738 11.1524 1.13453 72 2888 11.5821 1.11855 76 3035 10.7012 1.15365 80 3180 10.9908 1.20002 84 3323 12.0719 1.1369 88 3465 11.5038 1.1726 92 3604 12.0301 1.13639 96 3741 11.8978 1.17189 100 3877 11.0662 1.15387 104 4011 11.5244 1.16322 108 4143 12.6651 1.14425 112 4274 11.4769 1.14156 116 4403 12.1133 1.13053 120 4531 12.7013 1.15161 124 4657 12.2355 1.14152 128 4782 12.5706 1.14117 132 4906 11.675 1.14645 136 5029 13.0597 1.15231 140 5150 12.5677 1.13366 144 5271 12.7383 1.15082 148 5390 13.3914 1.19135 152 5509 12.8096 1.16674 156 5626 12.5167 1.14301 160 5743 13.0625 1.13424 164 5860 13.2473 1.16503 168 5975 13.0636 1.16463 172 6090 13.1265 1.15158 176 6205 12.7065 1.16209 180 6319 12.7256 1.14062 184 6433 12.6948 1.18071 188 6547 13.3953 1.13837 192 6660 13.7845 1.14575 196 6773 12.9962 1.18448 200 6886 13.1803 1.14086 204 6999 13.9405 1.13651 208 7112 13.6209 1.17095 212 7225 12.8161 1.18493 216 7338 13.6289 1.14073 220 7451 12.9969 1.14126 224 7564 13.0298 1.15171 228 7677 13.875 1.24404 232 7790 13.4989 1.17141 236 7903 13.2351 1.13043 240 8016 13.5397 1.15184 244 8129 13.9452 1.13878 246 8185 12.633 1.17642 248 8242 13.34 1.15632 249 8270 13.4511 1.12161 250 8298 13.1314 1.12135 251 8326 12.4477 1.1258 252 8354 13.1518 1.16355 253 8383 12.4853 1.14053 254 8411 12.6356 1.1198 255 8439 12.5064 1.1452 256 8467 12.6854 1.15578 257 8496 12.5533 1.14484 258 8524 11.9558 1.16978 259 8552 11.3911 1.12603 260 8580 12.0369 1.13757 261 8609 11.7561 1.15552 262 8637 11.0583 1.14379 263 8665 11.758 1.12698 264 8693 11.4058 1.2079 265 8722 11.8799 1.12799 266 8750 11.7153 1.1579