Satellite imagery and volume-area scaling are used to asses the glacier area and ice volume of Iceland from the Little Ice Age maximum to present day, obtaining a final result in sea level rise between 1890 - 2015. The Little Ice Age was a time of regional cooling, with glaciers reaching their maximum extent (~1890 for Iceland) with warming and glacier retreat after this period ended. Ice volume estimates are important to know due to their relevance in potential sea level rise calculations. Understanding both of these estimations for Iceland connects the impact a changing climate has on regional and global scales. Different scaling parameters used in the volume-area scaling approach to determine ice volume and ultimately sea level equivalents highlight the range of estimates acquired and point out the need in choosing appropriate values based on glacier region. A comparison to using mass balance measurements for volume estimates is also noted, showing differences in ice volume loss over past and present time periods. The Icelandic glacier area for present day is an updated value from previous studies at 10,803 ± 83 km2 and a first ever reported Icelandic Little Ice Age maximum glacier area of 12,201 ± 91 km2. For potential sea level rise, it is found the most reliable estimate from the volume- area scaling assessment is 2.67 mm from the Little Ice Age maximum to present day, with a yearly contribution since 1890 of 0.02 mm. / Satellitbilder och volym-area skalningsmetoden användes för att uppskatta glaciärarea och isvolym på Island från Lilla istiden till nutid, för att få fram hur stor höjningen av havsnivån varit under denna tidsperiod (1890 – 2015). Den lilla istiden var en tid av regional kylning då glaciärer nådde sin maximala utsträckning (~1890 för Island) följt av en snabb reträtt efter att denna period slutade. Uppskattningen av isvolym är viktigt att veta på grund av dess relevans i potentiella beräkningar av höjningen av havsnivån. Att förstå båda dessa uppskattningar för Island är kopplat till den påverkan ett förändrat klimat har på regional och global nivå. De olika skalparametrar som använts i volym-area skalningsmetoden för att bestämma volymen av is, och dess motsvarigheter i havsnivå, gav en rad av olika uppskattningar. Detta pekar på behovet att välja ett lämpligt parametervärde baserat på glaciärregionen. En jämförelse med att använda mätningar av massbalans för volymuppskattningar gjordes också, vilket visar skillnader i isvolymförlust över tidigare och nuvarande tidsperioder. Dagens värde på den isländska glaciärarean är uppdaterat från tidigare studier på 10,803 ± 83 km2 och den första rapporterade maximala isländska glaciärarean från Lilla istiden på 12,201 ± 91 km2. För potentiell höjning av havsnivån, har man funnit att den mest tillförlitlig uppskattning från volym-area skalningsmetoden är 2,67 mm från Lilla istidens maximum till nutid, med ett årligt bidrag sedan 1890 av 0,02 mm. (Översättning Cecilia Bayard.)

Submarine canyons are major geomorphic features, transporting large quantities of sediments from land to the deep sea. These sediments contain nutrients, enabling life in the deep sea and potentially forming hydrocarbon reservoirs. The transport of sediments towards the deep sea is also important as it links into fundamental concepts of the Earth’s system, such as the global carbon cycle and land surface denudation. Concepts based on the assumption of direct transport of sediments from land to the deep sea. However, how this transport occurs, on what timescales, and if there is potential storage of sediments along the way, is actually poorly known. The current theory is that gravity flow events, such as turbidity events, are the main mechanism behind canyon formation and maintenance. Luminescence dating, an absolute dating method, has been used in an earlier study to look at sediment transport via turbidity currents down the Monterey Canyon, off the coast of California, USA (Stevens et al., 2014). An active upper canyon was found at 1093 metres depth, with frequent events. At 3555 and 3612 metres depth the turbidity events dated were older and indications of major reworking of sediments were found. To pinpoint this change in environments, the present study used luminescence dating in order to get an age estimate of sediments at 2920 meter depth, creating a sequence of ages in the canyon. These cores have captured sediments that have been transported via sand waves, not turbidites. Sand waves are related to the frequent passing of turbidity events, but exact understanding of the mechanisms at hand is poorly understood. Single grain analysis on quartz is used to obtain the individual properties and ages of grains. This gives representative canyon entry ages of the sediments in addition to intrinsic grain properties. The data shows a skewed distribution of grain ages with a narrow, dominant peak between 180 and 240 years within a single core, indicating frequent flushing events and minor reworking of sediments. This is a similar pattern to the core at 1093 meter depth, albeit with increased age, suggesting temporary storage of sediment to at least a depth of 2920 metres. It is proposed that there is a gradual increase in ages down canyon towards 2900 meters depth with a more abrupt transition in environments with increased storage of sediments between 2900 and 3500 meter depth. Sand waves, and the exact relation to turbidites, remain a poorly understood transport mechanisms, but are potentially capable to transport vast amounts of sediments towards the deep sea. / Marina raviner transporterar stora mängder sand från land till havets botten. Men hur sker detta? I nuläget förklaras sandtransport med gravitationsflöde, att gravitationen drar ner sandkornen mot bottnen. Men sker detta vid ett enda stort skede eller i små gradvisa steg? Och kan det vara så att sand, på sin väg till botten, lagras i ravinerna? Det är dessa frågor som jag försöker att kasta ljus på i och med detta projekt.Målet var att komplettera vår kunskap om hur sand förflyttar sig från land till havsbotten genom att studera ifall det har skett en gradvis eller en abrupt transport av sand i ravinen Monterey Canyon vid Kaliforniens kust. Detta har jag gjort genom att datera åldern av sand vid ett djup av 2 920 meter, som i det här fallet deponerats av sandvågor, och sedan jämfört denna ålder med åldrarna på sanden från ett mindre (1 100 m) och större (3 500 m och djupare) djup, vilka analyserades i en tidigare studie (Stevens et al., 2014). Transportmekanism i den studien skiljer sig med min då det rör sig om gravitationsflöden.Med endast några få sandkorn av annan ålder så var den dominerande åldern på kornen i mitt prov mellan 180 till 240 år gamla. Provet vid 1 100 m djup visade sig också ha en liten spridning av ålder vilket tyder på att det skett återkommande utspolning av gammal sand som istället ersatts av ny. Man kan se att det ändå sker en tillfällig lagring av sediment mellan det minsta, studerade djupet och det nyligen tagna provet på 2 900 m, då en svag ökning i ålder kan mätas. Åldern på sandkornen i proven som kom från ett större djup var istället mycket spridd och generellt mycket högre än de från mindre djup. Att det finns en mix av ålder vid ett och samma djup tyder på att sanden vid återkommande tillfällen omfördelats i ravinen.Denna studie antyder att ravinen i fråga är aktiv upp till ett djup av minst 2 920 meter, med bara en svag stegring i ålder med ökande djup. Mellan 2 920 och 3 500 meter ändras miljön vilket gör att sprid-ningen av ålder ökar. Därutöver var det nya provet taget från en plats med ett annorlunda transport-mekanism, sandvågor istället för gravitationsflöde. Sandvågor, och dess relation till gravitationsflöden, är fortsättningsvis en dåligt förstådd transportmekanism som potentiellt är kapabel till att flytta stora mängder sediment till havets botten.

Hydrological modeling, like runoff modelling for flood prevention, is based on digital elevation models (DEMs). The fact that the DEMs do not represent existing road culverts can lead to considerable hydrological misinterpretations. In order to overcome this limitation, a GIS method was developed to automatically adjust the elevation model, hydrologically enforcing the DEM, so that the results of hydrological modeling accounts for flow through culverts. The hydro-enforced DEM showed to better represent the drainage network than the former DEM when compared with the river map. The topographic wetness index is the most commonly applied topographic index and a good indicator of soil moisture distribution. It has been integrated into many hydrological models and pollution risk indices as well as into the prediction of wetland distribution. Using the hydro-DEM from the previous step and the soil map in conjunction with the TWI, an improved TWI was achieved, namely a soil-topographic wetness index (STI). The linkages between specific soil types and TWI or STI values were analyzed. They revealed a clear linkage between STI values and soil type based on the soil transmissivity (R2=0.77). However, the TWI values showed low correlations to the soil types (R2=0.02). As a specific application, both TWI and STI were tested for the detection of wetlands. Wetlands are important ecosystems which act as buffer zones by filtering pollutants and slowing floodwater. Being able to identify their distribution is important in landscape planning and ecology. A wetland threshold value was determined for each index and their results where compared with the wetland map from the property map (assumed as ground truth) and with the potential wetland area. Finally, a visual validation was performed with the use of an aerial photography. The results showed that the STI performed slightly better than the TWI for the detection of wetlands, detecting 3% more wetlands. The impact of the soil map on the topographic wetness index was therefore determined as positive.

Climate change in the Arctic and sub-Arctic has induced substantial changes in the inland cryosphere. The warming climate is causing a reduction in glacier size and extent and the average net mass balance for Arctic glaciers have been negative over the past 40 years. Relatively few studies have been conducted concerning the development of the thermal distribution in glaciers during extensive volume changes. There is a possible diversity in how the thermal structure might change with a changing climate. Storglaciären is losing the cold surface layer in the ablation area and progressively becomes more temperate, while Kårsaglaciären is losing the zone of temperate ice in the ablation area and consequently becoming colder. The overall objective of this study has been to improve the understanding of the thermal response of polythermal glaciers to climate change. The results from Pårteglaciären, northern Sweden, indicate a decrease in volume by 18% in the last 15 years with an expected decrease of 35% of its present size during the coming century. As a consequence of the prevailing climate and volume decrease Pårteglaciären is experiencing a thinning of the cold surface layer at an average rate of 1.13 m a-1. The volumetric and cold surface layer changes are in the same magnitude, which may indicate that the CTS adapts relatively rapidly to the present changes. Assuming a climatic effect similar to what has been observed on Storglaciären, it can be concluded that the thinning has influenced the thermal regime. But in contrast to Kårsaglaciären, the thermal distribution on Pårteglaciären has become more temperate as a result of the substantial mass loss. / Klimatförändringar i Arktis och subarktis har orsakat stora förändringar i kryosfären. Ett varmare klimat orsakar en minskning av glaciärers storlek och omfattning och nettomassbalansen för Arktiska glaciärer har varit negativ under de senaste 40 åren. Relativt få studier har genomförts angående utvecklingen av den termiska fördelningen i glaciärer under omfattande volymförändringar. Det finns en möjlig diversitet i hur den termiska strukturen kan ändras med ett förändrat klimat. Storglaciären förlorar det kalla ytskiktet i ablationsområdet och blir successivt mer tempererad, medan Kårsaglaciären förlorar zonen med tempererad is i ablationsområdet och blir därmed kallare. Syftet med den här studien har varit att öka förståelsen för den termiska reaktionen hos polytermala glaciärer till ett förändrat klimat. Resultaten från Pårteglaciären i norra Sverige visar en volymreducering med 18% under de senaste 15 åren med en förväntad minskning på 35% av den nuvarande storleken under det kommande århundradet. Som en följd av det rådande klimatet och den reducerade volymen genomgår det kalla ytskiktet på Pårteglaciären en förtunning med en genomsnittlig hastighet av 1.13 m a-1. Volymförändringarna och förändringarna i kalla ytskiktet är i samma storleksordning, vilket tyder på att CTS anpassas relativt snabbt till de nuvarande förändringarna. Förutsatt en klimatisk effekt liknande den som observerats på Storglaciären, kan slutsatsen dras att förtunningen har påverkat den termiska regimen. Men i motsats till Kårsaglaciären har den termiska fördelningen på Pårteglaciären blivit mer tempererad som ett resultat av den omfattande massförlusten.

How great potential effect does the Black carbon emitted from the boreal forest fire region of Alaska have on the retreating glaciers of the St. Elias Mountains? In this study climate and forest fire history data of Alaska was run in the HYSPLIT wind trajectory model to generate trajectories originated from large occurring fires in Alaska from 2005 to 2014. Results show a small percentage of trajectories passing the St. Elias Mountains and an expected pattern of a correlation between passing trajectories and density of amount forest fires. Interdisciplinary climate research is indicating an increase in global temperatures with consequences such as an upswing of forest fires in the Northern Hemisphere. Inner Alaska is fire prone due to a combination of prevailing droughts during the summer season and frequent lightning ignition as a result from homogeneous vegetation and topography. Downwind from Alaska’s forest fire region is the ice field of the St. Elias Mountains, these glaciers are one of the fastest retreating due to increasing global temperatures and possible deposition of soot from Alaskan forest fires. Forest fire emits black carbon, which when deposited on snow or ice surfaces will decrease the albedo and accelerate the melting rate. Previous studies on ice cores from the St. Elias have investigated traces of combustion products from biomass burning. This indicates a possible record of historic forest fires in ice cores. The small percentage of passing trajectories in this study suggests that most large forest fires in Alaska might not be registered in the St. Elias ice cores.

Environmental scientists use ice-core records to reconstruct past atmospheric conditions. Anthropogenic and natural sources of emissions can be traced when analyzing ions in the ice, which is included in the science of glaciochemistry. Sulfate is an excellent ion to use in these studies since it is traceable to these emissions. This study is therefore focused on the sulfate ion, how its concentration has fluctuated over the last 200-years and when a change of trend occurred. The ice-cores used in this study were extracted at Lomonosovfonna, Svalbard, and analyzed by Ion Chromatography (IC). The new data that has been brought forth in this study covers nss-SO42- concentrations in the years of 1998-2012 and is connected to previous extracted ice-core records. The results of nss-SO42- concentration in the ice-cores confirm the change of trend in the 1970s. The increasing trend in the result correlate with historical emissions and the decrease after the change of trend enhances less anthropogenic impact on the atmosphere. / Miljöforskare använder sig av isborrkärnor för att återskapa tidigare atmosfäriska förhållanden. Antropogena och naturliga utsläppskällor kan spåras genom att analysera joner i isen. Sulfat är en utmärkt jon att använda sig av i dessa studier, eftersom den kan anknytas till dessa utsläpp. Denna studie fokuserar därför på sulfatjonen, hur dess koncentration har ändrats under de senaste 200-åren och på det trendbrott som har ägt rum. Isborrkärnorna som har använts i denna studie borrades upp på Lomonosovfonna, Svalbard, och analyserades med jonkromato-grafi. Ny data som har tagits fram i den här studien täcker nss-SO42- koncentrationen mellan 1998-2012 och är sammankopplad med tidigare framtagen data från samma plats. Resultatet av nss-SO42- koncentrationen i isborrkärnorna bekräftar trendbrottet som inträffade på 1970-talet. Den ökande trenden i resultatet korrelerar med historiska utsläpp och minskningen efter trendbrottet påvisar mindre antropogen påverkan på atmosfären.

The aim of this study was to map the prevalence of aeolian sand dunes in Västerbotten, northern Sweden to find dunes formed during earlier deglaciation phases, which was then preserved in cold-based conditions during the youngest stadial of the Weichselian glaciation. These preserved dunes were expected to be covered by a layer of till and have a rather faint morphology compared to dunes formed during the Holocene. Consequently, high resolution LIDAR-derived images from the Swedish mapping, cadastral and land registration authority (Lantmäteriet) was used to detect the dunes throughout an area covering most of Västerbotten, above the highest coastline and below the mountain range. The analysis resulted in several new findings of aeolian dunes compared to the findings in the quaternary soil map created by the Geological Survey of Sweden. Despite the fact some of the dunes at the LIDAR-derived image had a strange faint appearance, it was quickly evident during the fieldwork that the aeolian sand was not covered by till on any of the dunes visited. The common view during the last decades has been that cold-based ice will not erode or alter the morphology of the landscape beneath the ice. However, this study suggests that hypothesis may not be entirely correct, and therefore it can be hard to use geomorphological implications to reconstruct past glacial environments. Thus, it can be concluded that even under cold-based conditions, preservation of aeolian sand dunes in Västerbotten is probably not very common.

The trophic state of lakes is commonly defined by the concentration of nutrients in the water column. High nutrient concentrations generate high phytoplankton production, and lakes with low nutrient concentrations are considered low-productive. This simplified view of lake productivity ignores the fact that benthic primary producers and heterotrophic bacteria can be important basal producers in lake ecosystems. In this thesis I have studied clear-water and brown-water lakes with respect to primary production, respiration and bacterial production based on allochthonous organic carbon. These processes were quantified in pelagic and benthic habitats on temporal and spatial scales. I also calculated the net ecosystem production of the lakes, defined as the difference between gross primary production (GPP) and respiration (R). The net ecosystem production indicates whether a lake is net heterotrophic (GPP < R), net autotrophic (GPP > R) or in metabolic balance (GPP = R). Net heterotrophic lakes are sources of carbon dioxide (CO2) to the atmosphere since respiration in these lakes, by definition, is subsidized by an external organic carbon source. External organic carbon is transported to lakes from the terrestrial environment via inlets, and can serve as a carbon source for bacteria but it also limits light availability for primary producers by absorbing light. On a seasonal scale, four of the clear-water lakes studied in this thesis were dominated by primary production in the soft-bottom benthic habitat and by respiration in the pelagic habitat. Concentrations of dissolved organic carbon (DOC) were low in the lakes, but still high enough to cause the lakes to be net heterotrophic. However, the lakes were not low-productive due to the high production in the benthic habitat. One of the clear-water lakes was studied also during the winter and much of the respiration under ice was supported by the benthic primary production from the previous summer. This is in contrast to brown-water lakes where winter respiration is suggested to be supported by allochthonous organic carbon. By studying lakes in a DOC gradient (i.e. from clear-water to brown-water lakes) I could draw two major conclusions. The lakes became less productive since benthic primary production decreased with increasing light extinction, and the lakes became larger sources of CO2 to the atmosphere since pelagic respiration was subsidized by allochthonous organic carbon. Thus, lake carbon metabolism can have an important role in the global carbon cycle due to their processing of terrestrial organic carbon and to their possible feedback effects on the climate system.

Several scientific articles were mainly reviewed from Umeå’ s university database in order to determine the distribution, degree of contamination, and the sources of 7 selected heavy metals (Cr, Pb, Cu, Zn, Cd, Hg, Ni) in surface sediments along the coasts of the Mediterranean Sea. The Enrichment factor (EF) was used as pollution indicator to evaluate the extent of metal contamination in all the investigated areas. According to Abrahim and Parker (2008) the EF is defined as the ratio of the determined metal to Al (or Fe) in the sample divided by the ratio of background metal to background Al (or Fe) ratio. According to the results of this study, EF values for Cr, Pb, Cu, Cd and Ni presented an upward trend along the west to east shoreline of the Mediterranean sea, whereas Zn and Hg EF values showed a downward trend along this region. Cr generally exhibited no enrichment in places to the west (EF<1.5) whereas in the eastern side displayed moderate enrichment (EF=1.95). Pb EF values showed moderate enrichment (EF=5) along the western section of the sea, whilst in the eastern part revealed significant enrichment (5.45). Zn pollution levels were minimal (EF=1.6) in places to the west and moderate (EF=2.2) to the east. The enrichment for Cd was considered moderate in the western part of the basin and significant in the eastern section. These heavy metals distribution can be explained by the fact that different inputs (mainly due to anthropogenic activities) from the inshore environment may take place in each area of the sea. However, Cu and Ni presented the same degree of pollution (moderate) in the whole sea, presumably indicating similar Cu and Ni inputs from the terrestrial environment. However, conclusions for Hg were not possible to be drawn as the collected data were not sufficient.

Under 1700- och 1800-talet genomgick jordbruket omfattande förändringar som bottnade i ett behov av att utöka odlingsmarker men framför allt effektivisera jordbruket. Utvecklingen kom att betyda ett minskat behov av ängsmarker. Enligt tidigare forskning av Skåne var utvecklingen långsammare i de skånska skogsbygderna där ängsbruket vidhölls längre än de andra bygdetyperna.   Studien syftar således till att kartlägga de faktorer som varit särskilt betydande för ängsarealens utveckling i norra Skåne under den industriella revolutionen men även under den agrara revolutionen. För möjligheten att bedriva en övergripande undersökning har ett nedslag i tid gjorts – år 1910. Socknar som endast utgörs av höglänt landskap valdes ut att ingå i undersökningen. Med hjälp av tidigare forskning togs variablerna åker, vallodling, djurhållning och skiftesreform fram. Jordbruksstatistik från varje undersökningsområde i form av sockenareal, ängsareal, åkerareal, skörd från vallodling och antal djur hämtades från BiSOS (Bidrag till Sveriges officiella jordbruksstatistik). Statistik över skiftade byar hämtades från Lantmäteriets söktjänst Historiska kartor. Diverse uträkningar gjordes utifrån statistiken för att jämföra variablernas betydelse för ängens utbredning inom varje undersökningsområde.   I resultatet framgick att åkerarealen haft direkt påverkan på ängsarealens utbredning. Vallodling och djurhållning påverkades av åkerarealens utbredning och var därmed mer indirekt påverkande. Undersökningen av skiftesreformernas påverkan på ängsarealen visade att det inte finns ett samband mellan genomförd skiftesreform och ängsareal inom det höglänta landskapet. Med det inte sagt att skiftesreformerna inte hade betydelse för minskningen av äng. Vidare bekräftade resultatet att laga skiftet varit den dominerande skiftesreformen och att flest skiften genomfördes mellan årtalen 1827–1869. / Throughout the 18th and 19th centuries agriculture encountered an extensive conversion due to urgent expansion of croplands. The conversion was essential in establishing an efficient way in land cultivation additionally leading to decrease of meadowland farming.   Recent research of Scania showed that woodlands had a continuance of meadowland farming compared to other regions of landscapes. This study intent to map out reasons contributing to the decrease of meadowland in the north of Scania during the industrial revolution but also the agricultural revolution. An impact in time was chosen to accomplish a study covering a widely spread area – the year 1910. Study sites were defined to parishes exclusively including highland lands. Based on previous research the variables cropland, grassland, livestock and enclosure of farmlands were selected. Statistics of agriculture was collected from BiSOS (Contribution to Sweden’s official agricultural statistics) in distinction to each studied parish. Statistics of enclosure was collected from the search service Historic maps by The Swedish mapping, cadastral and land registration authority. Several calculations based on the statistics were accomplished to show how the variables affected the acres of meadowland.   According to the result croplands were the main affecting variable. Grassland and livestock had a secondary affect due to their depending on the extent of cropland. Furthermore, there was no indication that enclosure directly altered the meadowland farming within the highlands of Scania and not generally for Scania. Additionally, enclosure by law was the dominating form and most were achieved during the years of 1827-1869.