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Visar resultat 1 - 5 av 6 avhandlingar som matchar ovanstående sökkriterier.

1. 1. Summer Climate Variability during the Past 1200 Years in Central Scandinavia – A Tree-Ring Perspective

   Författare :Peng Zhang; Göteborgs universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Central Scandinavia; climate variability; dendroclimatology; maximum latewood density; Medieval Climate Anomaly; model-proxy data comparison; Pinus sylvestris L.; temperature; tree-ring width;

   Sammanfattning : To set the current 20th century warming in a long-term context, significant efforts have been made to reconstruct hemispheric-to-global temperatures beyond the instrumental period. Tree-rings, which have annual resolution and can be precisely dated, have been widely used to infer past climate variability. LÄS MER

3. 2. Historical anthropogenic radiative forcing of changes in biogenic secondary organic aerosol

   Författare :Juan Camilo Acosta Navarro; Ilona Riipinen; Annica Ekman; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES;

   Sammanfattning : Human activities have lead to changes in the energy balance of the Earth and the global climate. Changes in atmospheric aerosols are the second largest contributor to climate change after greenhouse gases since 1750 A.D. LÄS MER

4. 3. Tracing environmental change and human impact as recorded in sediments from coastal areas of the northwestern Baltic Proper

   Författare :Lena Norbäck Ivarsson; Elinor Andrén; Thomas Andrén; Mikael Lönn; John Anderson; Södertörns högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Baltic Sea; paleoecology; diatom stratigraphy; stable nitrogen isotopes; hypoxia; nutrient discharge; eutrophication; Medieval Climate Anomaly; Little Ice Age; Environmental Studies; Miljövetenskapliga studier; Östersjö- och Östeuropaforskning; Baltic and East European studies;

   Sammanfattning : The eutrophication of the Baltic Sea due to increased anthropogenic nutrient loads during the 20th century is well documented and studied. However, in the Baltic Sea drainage area, humans have affected the environment longer than the environmental monitoring can provide data for. LÄS MER

5. 4. Long-term development of subalpine lakes : effects of nutrients, climate and hydrological variability as assessed by biological and geochemical sediment proxies

   Författare :Manuela Milan; Christian Bigler; Monica Tolotti; Richard Bindler; Krystyna Szeroczyńska; Atte Korhola; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Paleolimnology; diatoms; Cladocera; sub-fossil pigments; geochemistry; wavelengthdispersive X-ray fluorescence spectroscopy; Lake Garda; Lake Ledro; reference conditions; nutrient enrichment; climate change; hydrological regime.;

   Sammanfattning : Sediment records of two Italian subalpine lakes (Lake Garda and Lake Ledro) were analyzed in order to reconstruct their ecological evolution over the past several hundred years. A multi-proxy and multi-site approach was applied in order to disentangle the effects of local anthropogenic forcings, such as nutrients, and climate impacts on the two lakes and their catchments. LÄS MER

7. 5. Tree-rings and climate - Standardization, proxy-development, and Fennoscandian summer temperature history

   Författare :Jesper Björklund; Göteborgs universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Tree rings; Fennoscandia; summer temperature; maximum latewood density MXD ; blue intensity BI ; standardization;

   Sammanfattning : Instrumental meteorological observation are too short for trying to estimate climate change and variability on multi-decadal and centennial time-scales, and when trying to evaluate the response of the climate system to human influence, such as raised concentrations of green house gases (GHG), altered land-use, black carbon etc. To access information about the climate system predating instrumental observations, reliable proxy records (natural archives) are necessary. LÄS MER