Sökning: "climate reconstructions"

Visar resultat 6 - 10 av 59 avhandlingar innehållade orden climate reconstructions.

  1. 6. Modelling ice surface elevation changes in Dronning Maud Land, East Antarctica : Bridging the gap between in-situ and numerical model reconstructions

    Författare :Martim Mas e Braga; Arjen P. Stroeven; Irina Rogozhina; Jonathan M. Harbor; Clas Hättestrand; Frank Pattyn; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; ice sheet modelling; glaciology; paleoglaciology; naturgeografi; Physical Geography;

    Sammanfattning : Ice sheets are an active component of Earth's climate system. Their topography influences atmospheric circulation and changes in their volume alters freshwater fluxes to the oceans, affecting ocean water masses, atmospheric carbon uptake, and global sea level. LÄS MER

  2. 7. Intramolecular isotope analysis reveals plant ecophysiological signals covering multiple timescales

    Författare :Thomas Wieloch; Jürgen Schleucher; Mats Nilsson; Gerd Gleixner; Lisa Wingate; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NMR spectroscopy; tree ring; isotope ratio; isotope effect; intramolecular 13C 12C signal; carbon allocation; acclimation; plant performance; climate reconstruction; plant ecophysiology;

    Sammanfattning : Our societies' wellbeing relies on stable and healthy environments. However, our current lifestyles, growth-oriented economic policies and the population explosion are leading to potentially catastrophic degradation of ecosystems and progressive disruption of food chains. LÄS MER

  3. 8. Modelling the early to mid-Holocene Arctic climate

    Författare :Marit Berger; Arne Johansson; Rodrigo Caballero; KTH; []
    Nyckelord :Arctic; early Holocene; mid-Holocene; climate modelling; paleoclimate; sea ice; climate change;

    Sammanfattning : In the recent past it has become evident that the Earth's climate is changing, and that human activity play a significant role in these changes. One of the regions where the ongoing climate change has been most evident is in the Arctic: the surface temperature has increased twice as much in this region as compared to the global average, in addition, a significant decline in the Arctic sea-ice extent has been observed in the past decades. LÄS MER

  4. 9. Tree Rings as Sensitive Proxies of Past Climate Change

    Författare :Håkan Grudd; Wibjörn Karlén; Brian Luckman; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Tree ring; width; density; climate; temperature; change; variability; sensitivity; Torneträsk; Tornetrask; Sweden; Fennoscandia; explosive; volcanic; eruption; Santorini; Thera; subfossil; Fitzroya; Chile; Physical geography; Naturgeografi;

    Sammanfattning : In the boreal forests of the Northern Hemisphere, time series of tree-ring width (TRW) and maximum density in the latewood (MXD) are highly correlated to local instrumental summer-temperature data and are thus widely used as proxies in high-resolution climate reconstructions. Hence, much of our present knowledge about climatic variability in the last millennium is based on tree-rings. LÄS MER

  5. 10. Pollen productivity estimates and pollen-based reconstructions of Holocene vegetation cover in Northern and temperate China for climate modelling

    Författare :Furong Li; Marie-José Gaillard; Mary E. Edwards; Linnéuniversitetet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; climate; pollen-vegetation relationships; relative pollen productivity; REVEALS model; anthropogenic land-cover change; Holocene; China; Paleoecology; Paleoekologi;

    Sammanfattning : Model projections of future climate change require that coupled climate-vegetation models are developed and validated, i.e. these models should be able to reproduce past climate and vegetation change. Records of pollen deposited in lake bottoms and peat bogs can provide the information needed to validate these models. LÄS MER