Sökning: "climate reconstructions"

Visar resultat 1 - 5 av 59 avhandlingar innehållade orden climate reconstructions.

  1. 1. Holocene Climate in Central and Southern Sweden : Quantitative Reconstructions from Fossil Data

    Författare :Karin Antonsson; Keith Bennett; Heikki Seppä; Andy Lotter; Uppsala universitet; []
    Nyckelord :Quaternary geology; pollen analysis; climate reconstructions; transfer functions; vegetation dynamics; Sweden; Kvartärgeologi;

    Sammanfattning : In quantitative palaeoecology modern species-environmental relationships can be statistically modelled, and recent development has made the calibration models more statistically robust. These models are used to transform fossil assemblages to quantitative estimates of past environmental conditions. LÄS MER

  3. 2. Paleoclimate perspective on Earth's climate sensitivity and feedbacks

    Författare :Martin Renoult; Thorsten Mauritsen; Navjit Sagoo; Masa Kageyama; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Paleoclimate; Climate sensitivity; Climate feedbacks; Last Glacial Maximum; Pliocene; Snowball Earth; Emergent constraint; Atmospheric Sciences and Oceanography; atmosfärvetenskap och oceanografi;

    Sammanfattning : The addition of carbon dioxide (CO2) in the atmosphere due to human activities is the main driver of global warming. How much the Earth will warm in the future is often represented by the Earth's equilibrium climate sensitivity (ECS), the long-term temperature response considering the effect of climate feedbacks after an abrupt and sustained doubling of atmospheric CO2 from pre-industrial concentration. LÄS MER

  4. 3. Paleoclimate and seasonality on Sumatra during the Late Glacial and Holocene : Insights from biomarkers and climate model simulations

    Författare :Lars Petter Hällberg; Malin Kylander; Frederik Schenk; Rienk Smittenberg; David Naafs; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Holocene; Late Glacial; biomarkers; organic geochemistry; climate model; hydrogen isotopes; stable isotopes; paleoclimate; alkanes; GDGT; brGDGT; H-GDGT; bacterial community shifts; paleothermometry; precipitation reconstruction; peat; geokemi; Geochemistry;

    Sammanfattning : Deep atmospheric convection in the Indo-Pacific Warm Pool (IPWP) is a key driver of the Hadley and Walker Circulations that modulate the Asian-Australian monsoons and the El Niño Southern Oscillation (ENSO). Temperature and rainfall seasonality, i.e. LÄS MER

  5. 4. Holocene environmental changes and climate variability in the Eastern Mediterranean : Multiproxy sediment records from the Peloponnese peninsula, SW Greece

    Författare :Christos Katrantsiotis; Stefan Wastegård; Rienk Smittenberg; Jan Risberg; Elin Norström; Sherilyn Fritz; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Mediterranean; Greece; Peloponnese; Holocene; sediments; diatoms; n-alkanes; stable isotopes; tectonics; climate variability; monsoons; NAO; NCP; Physical Geography; naturgeografi;

    Sammanfattning : This thesis presents multiproxy reconstructions of the mid to late Holocene climate and environmental changes in the Peloponnese peninsula, SW Greece. The combined dataset consists of diatom, biomarker and X-ray fluorescence spectrometry (XRF) elemental data in radiocarbon-dated sediment cores taken from the Agios Floros fen and the Gialova Lagoon in SW Peloponnese and the Ancient Lake Lerna in NE Peloponnese. LÄS MER

  7. 5. Disentangling production and climate signals from high-resolution Beryllium records: implications for solar and geomagnetic reconstructions

    Författare :Minjie Zheng; MERGE: ModElling the Regional and Global Earth system; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Solar Activity; 10Be; 7Be; ice cores; tropopause; climate; cosmogenic radionuclides; geomagnetic reconstructions; multi-linear regression;

    Sammanfattning : The sun is the most important energy source for the Earth’s climate system, however, influences of solar variations on climate are not fully understood. Studying past solar activity can improve our understanding of what role the sun plays in Earth’s climate. LÄS MER