| 1. |
- Holmgren, Erik, 1993, et al.
(författare)
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Exploring the sensitivity of extreme event attribution of two recent extreme weather events in Sweden using long-running meteorological observations
- 2024
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Ingår i: Natural Hazards and Earth System Science. - 1561-8633 .- 1684-9981. ; 24:8, s. 2875-2893
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Tidskriftsartikel (refereegranskat)abstract
- Despite a growing interest in extreme event attribution, attributing individual weather events remains difficult and uncertain. We have explored extreme event attribution by comparing the method for probabilistic extreme event attribution employed at World Weather Attribution (https://www.worldweatherattribution.org, last access: 22 August 2024) (WWA method) to an approach solely using pre-industrial and current observations (PI method), utilising the extensive and long-running network of meteorological observations available in Sweden. With the long observational records, the PI method is used to calculate the change in probability for two recent extreme events in Sweden without relying on the correlation to the global mean surface temperature (GMST). Our results indicate that the two methods generally agree for an event based on daily maximum temperatures. However, the WWA method results in a weaker indication of attribution compared to the PI method, for which 12 out of 15 stations indicate a stronger attribution than found by the WWA method. On the other hand, for a recent extreme precipitation event, the WWA method results in a stronger indication of attribution compared to the PI method. For this event, only 2 out of 10 stations assessed in the PI method exhibited results similar to the WWA method. Based on the results, we conclude that at least one out of every two of heat waves similar to the summer of 2018 can be attributed to climate change. For the extreme precipitation event in Gävle in 2021, the large variations within and between the two methods make it difficult to draw any conclusions regarding the attribution of the event.
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| 2. |
- Johansson, Pär, 1986, et al.
(författare)
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Tak i urbana miljöer för att minska risken för översvämning vid skyfall
- 2016
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Ingår i: Bygg & teknik. ; 2016:4, s. 48-50
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Hur påverkar framtida klimatscenarier översvämningsrisken i urbana områden? Vilka regnmängder klarar befintliga dagvattensystem? Går det att använda den byggda miljön mer effektivt för att hantera dagvatten? Gröna och blåa lösningar är ett hett ämne när det gäller ekosystemtjänster och för att effektivisera dagvattenhanteringen i tätbebyggda områden. I ett nystartat projekt på Chalmers kommer blåa och gröna lösningar att testas och modelleras. Huvudsyftet är att öka den yta som kan användas för fördröjning av dagvatten genom att använda de befintliga taken i staden.
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| 3. |
- Nielsen, Anker, 1945, et al.
(författare)
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Sustainability of the Swedish built environment towards climate change. Hygro-thermal effects and design criteria for buildings with respect to future climate scenarios
- 2007
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Ingår i: Thermal Performance of the Exterior Envelopes of Whole Buildings. - 2166-8469. ; 10th
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Konferensbidrag (refereegranskat)abstract
- The most of predictable climatic impacts on buildings can be successfully managed by an adequate construction. However, possible deviations in predicted loads and especially the long-term ones may change the building designed, e.g. expected response. For example, changes in snow and wind loads and short-time precipitation are of a great interest for constructions with large flat roofs. Climate projections from climate models point to a warmer climate with an intensified hydrological cycle in the future. Warmer summers lead to increased demand for cooling energy, while a warmer and more humid climate will possibly increase risks for moisture and mould-growth problems. This paper gives some outlines from a new research project on sustainability of Swedish built environment towards climate changes. The project will be conducted at Chalmers University of technology, Sweden, in cooperation with the climate research unit Rossby Centre at the Swedish Meteorological and Hydrological Institute.
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| 4. |
- Nik, Vahid, 1979, et al.
(författare)
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Assessment of hygrothermal performance and mould growth risk in ventilated attics in respect to possible climate changes in Sweden
- 2012
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Ingår i: Building and Environment. - : Elsevier BV. - 0360-1323. ; 55, s. 96-109
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Tidskriftsartikel (refereegranskat)abstract
- Most of the last 20 years in Sweden have been mild and wet compared to the 1961–1990 climate reference period. After a few relatively cold years in the mid-1980s, practically all years have been warmer than the preceding 30 years average. During the indicated period, an increase of moisture-related problems (mould growth) was observed in ventilated attics, a moisture sensitive building part.This work investigates hygrothermal performance of ventilated attics in respect to possible climate change. Hygrothermal simulations of attics were performed numerically in Matlab. Four attic constructions are investigated – a conventional attic and three alternative constructions suggested by practitioners. Simulations were done for the period of 1961–2100 using the weather data of RCA3 climate model. Effects of three different emissions scenarios are considered. Hygrothermal conditions in the attic are assessed using a mould growth model. Based on the results the highest risk of mould growth was found on the north roof of the attic in Gothenburg, Sweden. Results point to increment of the moisture problems in attics in future. Different emissions scenarios do not influence the risk of mould growth inside the attic due to compensating changes in different variables. Assessing the future performance of the four attics shows that the safe solution is to ventilate the attic mechanically, though this solution inevitably requires extra use of electrical energy for running the fan. Insulating roofs of the attic can decrease the condensation on roofs, but it cannot decrease the risk of mould growth considerably, on the wooden roof underlay.
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| 5. |
- Nik, Vahid, 1979, et al.
(författare)
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Statistical methods for assessing and analysing the building performance in respect to the future climate
- 2012
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Ingår i: Building and Environment. - : Elsevier BV. - 0360-1323. ; 53, s. 107-118
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Tidskriftsartikel (refereegranskat)abstract
- Global warming and its effects on climate are of great concern. Climate change can affect buildings in different ways. Increased structural loads from wind and water, changes in energy need and decreased moisture durability of materials are some examples of the consequences. Future climate conditions are simulated by global climate models (GCMs). Downscaling by regional climate models (RCMs) provides weather data with suitable temporal and spatial resolutions for direct use in building simulations. There are two major challenges when the future climate data are used in building simulations. The first is to handle and analyse the huge amount of data. The second challenge is to assess the uncertainties in building simulations as a consequence of uncertainties in the future climate data. In this paper two statistical methods, which have been adopted from climatology, are introduced. Applications of the methods are illustrated by looking into two uncertainty factors of the future climate; operating RCMs at different spatial resolutions and with boundary data from different GCMs. The Ferro hypothesis is introduced as a nonparametric method for comparing data at different spatial resolutions. The method is quick and subtle enough to make the comparison. The parametric method of decomposition of variabilities is described and its application in data assessment is shown by considering RCM data forced by different GCMs. The method enables to study data and its variations in different time scales. It provides a useful summary about data and its variations which makes the comparison between several data sets easier.
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| 6. |
- Ning, Tong, 1975, et al.
(författare)
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Atmospheric Water Vapor Content Inferred From GPS Data and Compared to a Global NWP Model and a Regional Climate Model
- 2008
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Ingår i: 2008.10.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Radio based space geodetic methods are affected by the water vapor in the atmosphere.The velocity of the propagating signal is reduced, depending on the value of the refractiveindex. The atmospheric water vapor content, sometimes also called Integrated WaterVapor (IWV), can be inferred from the estimated propagation delay, or the excess propagationpath often expressed in units of length. The observations are relative measurementsof time, which makes the methods interesting from a calibration point of view - since timeis the physical parameter that we can measure with the highest accuracy.Since water vapor is difficult, and costly, to measure with a high temporal and spatialresolution, given its characteristics of variability, researchers in the atmospheric scienceshave shown interest in using data from already existing ground-based continuously operatingGPS receivers. Time series of the IWV from specific sites are now longer than tenyears. For example, 20 sites in the Swedish GPS network have produced continuous datasince 1993/1994. In addition to GPS also additional global navigational satellite systems(GNSS), such as the European Galileo and the finalization of the Russian GLONASS, willin the future significantly improve the spatial sampling of the atmosphere, and also reducethe relative influence of orbit errors for individual satellites.We have analyzed ground-based GPS data acquired in Europe and Africa over the period2001-2006. IWV results from the GPS data analysis are compared to the global NumericalWeather Prediction (NWP) models from the European Center for Medium RangeWeatherForecasting (ECMWF) as well as the regional climate model of the Rossby Center.The overall goal for the possible use of GNSS data in climate research is to determine towhich extent these independent data can be used to discriminate between different climatemodels - both in terms of absolute values as well as long term trends - thereby improvingthe quality of the models and increasing the probability to produce realistic scenarios ofthe future climate.
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| 7. |
- Sasic Kalagasidis, Angela, 1968, et al.
(författare)
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Hygro-thermal response of a ventilated attic to the future climate load in Sweden
- 2009
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Ingår i: Proceedings of the fourth International Building Physics Conference. - 9789755613505 ; , s. 519-526
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Konferensbidrag (refereegranskat)abstract
- Universal in most climate change scenarios for the 21st century is the increase of the global mean temperature. By the end of the century the increase may be 1-6 oC depending on the chosen emission scenario. Climate scenarios for Sweden point to a warmer and more humid climate in future. It can be expected that the building parts, which are already susceptible for moisture load, will degrade more in future. In Sweden, a ventilated cold attic is a typical representative of a moisture-sensitive construction part. This paper investigates numerically the hygro-thermal response of a typical ventilated attic to a possible future climate load in Sweden. The hygro-thermal conditions in the attic are assessed by a mould growth index (MGI). The results showed the increment of MGI in future for all test cases. The analysis showed that the orientation of a roof and the moisture load to the attic from a dwelling underneath are the influencing parameters on MGI. Since the latter is governed mainly by the ventilation system in a house, the type of the ventilation system is important design parameter for the prevention of future moisture problems in ventilated attics.
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| 8. |
- Strandberg, Gustav, 1977-, et al.
(författare)
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Bespoke climate indicators for the Swedish energy sector − a stakeholder focused approach
- 2024
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Ingår i: Climate Services. - Göteborg : IVL Svenska Miljöinstitutet. - 2405-8807. ; 34, s. 100486-100486
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Tidskriftsartikel (refereegranskat)abstract
- Climate change concerns the energy sector to a high degree because the sector is sensitive both to changing conditions for power and heat production, and to changing demand for electricity, heating and cooling. In this study potential consequences of climate change on different parts of the Swedish energy sector were assessed in a series of workshops, where climate and energy scientists, energy systems experts and analysts met with representativesof the energy sector to assess the vulnerability of the sector and consider what climate indicators could be used to assess impacts of relevance. The impact of climate change depends on the energy type. Hydropower, for which production is naturally linked to weather and climate, is significantly impacted by climate change. For other forms of production, such as nuclear power, other factors such as e.g. policy and technology development are more important. The series of workshops held in this study, where different aspects of climate change and consequences were discussed, proved very successful and has increased our understanding of climate impacts on the energy system.
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