| 1. |
- Linderson, Maj-Lena
(författare)
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Spatial distribution of meso-scale precipitation in Scania, southern Sweden
- 2003
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Ingår i: Geografiska Annaler. Series A. Physical Geography. - : Informa UK Limited. - 0435-3676 .- 1468-0459. ; 85:2, s. 183-196
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study is to analyse the spatial variability of meso-scale precipitation in Scania and to assess the influence of synoptic scale atmospheric circulation. The modes of spatial variation are revealed by EOF analysis of monthly precipitation totals between 1963 and 1990, which were obtained from a dense rain-gauge network in Scania. southern Sweden. The influence of local physiography on the spatial distribution of precipitation is assessed by GIS techniques using a digital elevation model of Scania. The relation to synoptic scale atmospheric circulation is analysed using regional circulation indices and weather types. It is shown that the daily precipitation distribution in the area is significantly influenced by synoptic scale pressure patterns. Nevertheless. the covariability of the monthly precipitation within Scania is high. About 80% of the precipitation variability is connected to the passage of low-pressure centres over or close to the region. which are likely to produce precipitation over the whole area. A wind-direction dependency found in the distribution indicates that there might be a limit between precipitation regimes within the landscape. Topography greatly influences the spatial distribution in Scania. The distribution of land and surrounding sea is also an important factor and makes the relationship between physiography and precipitation rather complex. The physiographical effects vary over a single year. The dampening effect of the sea on the atmospheric temperature influences the local stability in coastal areas and results in seasonally dependent precipitation patterns.
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| 2. |
- Andresen, Camilla Snowman, et al.
(författare)
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Sholocene climate variability in the Denmark Strait region - A land-sea correlation of new and existing climate proxy records
- 2005
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Ingår i: Geografiska Annaler. Series A. Physical Geography. - : Informa UK Limited. - 0435-3676 .- 1468-0459. ; 87:1, s. 159-174
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Tidskriftsartikel (refereegranskat)abstract
- Two well dated Holocene sediment records bordering the Denmark Strait region have been used to reconstruct past climate variability. The content of biogenic silica, clastic and organic material and moss in a lacustrine record from Lake N14 has been used to infer past variability in precipitation and temperature in southern Greenland. Sedimentologic and petrologic composition of sand in a shelf sediment record from the Djupall trough is used to infer past variability in the northwestern storm activity on northwestern Iceland, which probably also affected the inflow of polar waters from the East Greenland Current. Our evaluation of these records with a number of previous studies from the region documents Holocene climatic optimum conditions peaking between 8000 and 6500 calendar years before present (cal yr BP). Mid-Holocene climate deterioration set in around 5000 cal yr BP followed by a further marked setback around 3500 cal yr Bp. A stacking of climate variability on a centennial timescale from previous studies in the area shows a fairly good correspondence to the timing of marked cold and warm events as evidenced from the Lake N14 and the Djupull trough records. Cooler periods are explained as the response to marked incursions of ice-laden polar water from the Arctic Ocean to the Denmark Strait region. Cool northerly and northwesterly winds along the East Greenland coast in relation to frequent strong atmospheric low pressure in the Barents Sea, coupled with strong high pressure over Greenland, would have favoured southward export of polar waters. A comparison with the proxy records of nuclide production (C-14 and Be-10) suggests that solar activity may have had some influence on the atmospheric pressure distribution in the Denmark Strait region.
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| 3. |
- Håkansson, Lena, et al.
(författare)
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Cosmogenic Be-10-ages from the Store Koldewey island, NE Greenland
- 2007
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Ingår i: Geografiska Annaler. Series A. Physical Geography. - : Informa UK Limited. - 0435-3676 .- 1468-0459. ; 89A:3, s. 195-202
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Tidskriftsartikel (refereegranskat)abstract
- Earlier work in northeast Greenland has suggested a limited advance of the Greenland Ice Sheet during the Last Glacial Maximum (LGM). However, this concept has recently been challenged by marine geological studies, indicating grounded ice on the continental shelf at this time. New Be-10-ages from the Store Koldewey island, northeast Greenland, suggest that unscoured mountain plateaus at the outer coast were covered at least partly by cold-based ice during the LGM. It is, however, still inconclusive whether this ice was dynamically connected to the Greenland Ice Sheet or not. Regardless of the LGM ice sheet extent, the Be-10 results from Store Koldewey add to a growing body of evidence suggesting considerable antiquity of crystalline unscoured terrain near present and Pleistocene ice sheet margins.
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| 4. |
- Mattsson, Jan
(författare)
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Sven Lindqvist and his scientific contribution
- 2007
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Ingår i: Geografiska Annaler. Series A. Physical Geography. - : Informa UK Limited. - 0435-3676 .- 1468-0459. ; 89A:4, s. 219-222
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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| 5. |
- Ridefelt, Hanna, et al.
(författare)
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56 years of solifluction measurements in the Abisko mountains, northern Sweden - analysis of temporal and spatial variations of slow soil surface movement
- 2009
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Ingår i: Geografiska Annaler. Series A. Physical Geography. - : Informa UK Limited. - 0435-3676 .- 1468-0459. ; 91A:3, s. 215-232
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Tidskriftsartikel (refereegranskat)abstract
- Solifluction movement rates from 1952 to 2008 for the Abisko region, northern Sweden, have been compiled and analysed through correlation tests and multiple regression. The temporal analysis is based on two datasets (Lobe11 & gridAB and Line B) from Karkevagge. The dataset Lobe11 & gridAB show a strong correlation between movement rates and mean annual air temperature (MAAT) and MAAT is also identified as one of the significant contributing parameters in the multiple regression model. No significant correlations were found for the Line B dataset. The spatial analysis indicates generally higher movement rates in the western part of the region and at lower altitudes mainly between 700 and 900 m a.s.l., but the spatial variability is high. To reduce the influence of the temporal variation the data for the correlation tests of the spatial variations were divided into two parts: 1957 to 1980 and 1981 to 2008. The correlation analysis of the dataset 1957 to 1980 shows a significant negative correlation between annual average movement rates and permafrost probability and altitude. The dataset 1981 to 2008 shows a positive correlation between movement rates and wetness index. It is concluded that movement rates may increase with higher MAAT in the western part of the region (Karkevagge), the spatial variability of movement rates within the region is very high and that altitude (and/or permafrost) together with wetness index are the main controls on the regional spatial variation. The study highlights the limitations in establishing statistical relationships between movement rates and climate using data from different field empirical studies.
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| 6. |
- Yang, Zhenlin, et al.
(författare)
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Modelling Surface-Air-Temperature Variation Over Complex Terrain Around Abisko, Swedish Lapland: Uncertainties Of Measurements And Models At Different Scales
- 2011
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Ingår i: Geografiska Annaler. Series A. Physical Geography. - : Informa UK Limited. - 0435-3676 .- 1468-0459. ; 93A:2, s. 89-112
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Tidskriftsartikel (refereegranskat)abstract
- P>Many ecological, physical and geographical processes affected by climate in the natural environment are scale-dependent: determining surface-air-temperature distribution at a scale of tens to hundreds of metres can facilitate such research, which is currently hampered by the relative dearth of meteorological stations and complex surface temperature characteristics, particularly in mountain areas. Here we discuss both the couplings and mismatch of present climatological data at different scales, ranging from similar to 50 m to 100 km, and provide a novel model of the surface-air-temperature distribution in topographically heterogeneous regions. First, a comparison of the large-scale weather station measurements and gridded climate reanalysis (ERA-40) data is used to define regional climatology in the Swedish sub-Arctic and obtain the mesoscale temperature lapse rates. Second, combined with temperature measurements obtained from transects set among complex terrain, key microclimatic characteristics of the temperature distribution are identified, showing few temperature inversions when the wind speed exceeds 3 m s-1, while temperature inversions prevail during calm nights. Besides wind, there is a pronounced winter temperature stratification around the large Lake Tornetrask, and variations in topography are found to have a strong influence in shaping the microscale temperature pattern through their effect on solar radiation during summer. A monthly 50-m scale temperature-distribution (topoclimate) model is built based on the above findings, and model validation is conducted using further fieldwork measurements from different seasons. We present results of surface-air-temperature distribution for the Abisko region, and discuss how these results help reconcile the scale mismatch mentioned above.
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| 7. |
- Kalińska, Edyta, et al.
(författare)
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The Raunis section, central Latvia, revisited : first luminescence results and re-evaluation of a key Baltic States stratigraphic site
- 2020
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Ingår i: Geografiska Annaler, Series A: Physical Geography. - : Informa UK Limited. - 0435-3676 .- 1468-0459. ; 102:4, s. 376-396
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Tidskriftsartikel (refereegranskat)abstract
- In interstadial deposits, sand interbeds gain limited consideration in comparison with organic sediments, and therefore tend to be underrepresented in paleoenvironmental reconstructions. The Raunis site, central-eastern Latvia, is an example where organic beds have already gained some attention and been used to understand the complex interactions between advance and retreat of the Scandinavian Ice Sheet in the region. Sandy interlayers have so far not been investigated in detail and their time of deposition has also been unknown, therefore exploring these clastic-organic sediment alternation is of interest. This study provides a new set of luminescence datings along with sedimentological information from the character of individual quartz grains as detected from scanning electron microscope analysis. Sandy interlayers are dated to between 12 and 122 ka. Fast component OSL signal dominates in all investigated samples, but several samples have broad and/or skewed dose distributions. Only one sample is considered reliable and provides an age of 12.0 ± 0.6 ka. A radiocarbon age from organic sediments in the same unit yields an age of 14 025 ± 270 cal y BP. These two dates do not agree within 2 sigma, and this is likely related to reservoir and hard water effects of the radiocarbon sample. Sediments at the Raunis site fall into the Greenland Interstadial 1, but more detailed specification is not possible. The rest of the OSL ages are older than expected, likely due to incomplete bleaching during deposition. This means that stratigraphic reliability of this key site is likely hampered for further regional correlation.
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| 8. |
- Kalinska-Nartisa, Edyta, et al.
(författare)
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Sandy fan-like forms in the central-eastern mazovian lowland (central poland) : Textural record and chronology
- 2016
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Ingår i: Geografiska Annaler, Series A: Physical Geography. - : Informa UK Limited. - 0435-3676 .- 1468-0459. ; 98:2, s. 111-127
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Tidskriftsartikel (refereegranskat)abstract
- A unique, continuous, fan-shaped belt of sandy landforms in the central-eastern Mazovian Lowland, Central Poland has been investigated using a multiproxy dataset of sediment physical properties and chronological framework. Although there are several previous studies of similar fan-like forms elsewhere in Central Poland, this central-eastern part has not been investigated in detail. A combined methodological approach, using grain-size distributions, the roundness, surface character and microtexture of quartz grains, and the mineral composition of the light and heavy fractions, indicate a predominantly aeolian origin for the fan-like forms. Overlying them are dunes, the sediment within which is derived mainly from the fan-like forms. Two main aeolian phases are distinguished based on luminescence ages: (1) between around 15 and 16 ka, possibly correlated with the Pomeranian Phase of the last (Vistulian) glaciation in Poland, and representing a phase with a poorly recorded deflation event; and (2) around 12 ka, associated with the Younger Dryas onset, when fresh, non-aeolian material was delivered to the system. Overall, the palaeoenvironmental pattern of the fan-like forms is controlled by the Upper Pleistocene aeolian trends.
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| 9. |
- Möller, Per
(författare)
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Subrecent moraine ridge formation on Cuff Cape, Victoria Land, Antarctica
- 1995
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Ingår i: Geografiska Annaler, Series A: Physical Geography. - : Informa UK Limited. - 0435-3676 .- 1468-0459. ; 77:1-2, s. 83-94
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Tidskriftsartikel (refereegranskat)abstract
- A small bedrock ridge called Cuff Cape, protruding from an ice field in the inner part of Granite Harbour, Victoria Land, Antarctica, carries a system of moraine ridges. Cuff Cape was during deglaciation bounded to the south by a terrestrial, slow-retreat ice margin and towards the north and west by a faster-retreat, marine-based ice margin. Based on studies of contemporary processes along the present ice margin, sediment facies states of logged trenches and the morphology of the moraines, it can be concluded that moraines on low altitudes are composed of sediments deposited in fluvial troughs and meltwater ponds along a frontal glacier apron. The sediments were primarily deposited as debris flow diamictons, generated from melted-out sediments from basal debris bands and sorted sediments deposited as traction load and suspended load sediments in the marginal ponds. These sediments were in a frozen state later glaciotectonically thrust and stacked into moraine ridges during minor readvance stages. The largest moraine, covering a narrow retreat zone, was formed along the terrestrial ice margin by means of push and stacking of frontal apron diamictons. This moraine also carries superimposed minor ridges along its proximal slope, suggesting frequent readvance stages. Based on a survey of Cuff Cape, carried out by the English Terra Nova expedition in 1910–1913, it can be concluded that the youngest moraine has been formed since then. The absence of lichen growth on the moraines also suggests that they are of a very recent age.
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| 10. |
- Clark, Eric
(författare)
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Book review
- 2005
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Ingår i: Geografiska Annaler. Series A. Physical Geography. - 0435-3676. ; 87:4, s. 300-302
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Recension (övrigt vetenskapligt/konstnärligt)
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