| 1. |
- Happonen, Maija, et al.
(författare)
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Aviation's climate impact allocated to inbound tourism: decision-making insights for "climate-ambitious" destinations
- 2023
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Ingår i: Journal of Sustainable Tourism. - : Informa UK Limited. - 1747-7646 .- 0966-9582. ; 31:8, s. 1885-1901
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Tidskriftsartikel (refereegranskat)abstract
- The climate impact from international aviation was 2.4% of the world's total climate impact in 2018, and is expected to grow. International regulation of this impact is not aligned with trajectories to stay below 1.5 degrees C of global warming. Conventional approaches to allocating climate impact to international aviation also lack one of the important drivers for air travel: tourism. Existing studies have focused on the carbon footprint of residents' outbound air travel, but there is a lack of focus on the climate impact from inbound air travel. This article quantifies the climate impact of inbound air travel, and presents it alongside the impact of outbound air travel, to get a full picture of the climate impact of tourism-driven air travel and provide insights for tourism's decision-makers. This was done in a case study for Sweden. The results show that the emissions from inbound air travel have grown 3 times more than emissions from outbound air travel each year, at a faster rate than the yearly growth for all international air travel. Responsibility for the climate impacts of inbound and outbound air travel is discussed, along with further actions such as demarketing and focusing on closer source markets.
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| 2. |
- Westerberg, Ida, et al.
(författare)
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Precipitation data in a mountainous catchment in Honduras: quality assessment and spatiotemporal characteristics
- 2010
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Ingår i: Theoretical and Applied Climatology. - : Springer Nature. - 0177-798X .- 1434-4483. ; 101:3-4, s. 381-396
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Tidskriftsartikel (refereegranskat)abstract
- An accurate description of temporal and spatial precipitation variability in Central America is important for local farming, water supply and flood management. Data quality problems and lack of consistent precipitation data impede hydrometeorological analysis in the 7,500 km2 Choluteca River basin in central Honduras, encompassing the capital Tegucigalpa. We used precipitation data from 60 daily and 13 monthly stations in 1913–2006 from five local authorities and NOAA's Global Historical Climatology Network. Quality control routines were developed to tackle the specific data quality problems. The quality-controlled data were characterised spatially and temporally, and compared with regional and larger-scale studies. Two gapfilling methods for daily data and three interpolation methods for monthly and mean annual precipitation were compared. The coefficient-of-correlation-weighting method provided the best results for gap-filling and the universal kriging method for spatial interpolation. In-homogeneity in the time series was the main quality problem, and 22% of the daily precipitation data were too poor to be used. Spatial autocorrelation for monthly precipitation was low during the dry season, and correlation increased markedly when data were temporally aggregated from a daily time scale to 4–5 days. The analysis manifested the high spatial and temporal variability caused by the diverse precipitationgenerating mechanisms and the need for an improved monitoring network.
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| 5. |
- Gumbel, Jörg, et al.
(författare)
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The MATS satellite mission - gravity wave studies by Mesospheric Airglow/Aerosol Tomography and Spectroscopy
- 2020
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Ingår i: Atmospheric Chemistry And Physics. - : COPERNICUS GESELLSCHAFT MBH. - 1680-7316 .- 1680-7324. ; 20:1, s. 431-455
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Tidskriftsartikel (refereegranskat)abstract
- Global three-dimensional data are a key to understanding gravity waves in the mesosphere and lower thermosphere. MATS (Mesospheric Airglow/Aerosol Tomography and Spectroscopy) is a new Swedish satellite mission that addresses this need. It applies space-borne limb imaging in combination with tomographic and spectroscopic analysis to obtain gravity wave data on relevant spatial scales. Primary measurement targets are O-2 atmospheric band dayglow and nightglow in the near infrared, and sunlight scattered from noctilucent clouds in the ultraviolet. While tomography provides horizontally and vertically resolved data, spectroscopy allows analysis in terms of mesospheric temperature, composition, and cloud properties. Based on these dynamical tracers, MATS will produce a climatology on wave spectra during a 2-year mission. Major scientific objectives include a characterization of gravity waves and their interaction with larger-scale waves and mean flow in the mesosphere and lower thermosphere, as well as their relationship to dynamical conditions in the lower and upper atmosphere. MATS is currently being prepared to be ready for a launch in 2020. This paper provides an overview of scientific goals, measurement concepts, instruments, and analysis ideas.
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| 6. |
- Kjellström, Erik, et al.
(författare)
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Simulated climate conditions in Europe during the Marine Isotope Stage 3 stadial
- 2010
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Ingår i: Boreas. - : Wiley. - 0300-9483 .- 1502-3885. ; 39:2, s. 436-456
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Tidskriftsartikel (refereegranskat)abstract
- State-of-the-art climate models were used to simulate climate conditions in Europe during Greenland Stadial (GS) 12 at 44 ka BP. The models employed for these simulations were: (i) a fully coupled atmosphere-ocean global climate model (AOGCM), and (ii) a regional atmospheric climate model (RCM) to dynamically downscale results from the global model for a more detailed investigation of European climate conditions. The vegetation was simulated off-line by a dynamic vegetation model forced by the climate from the RCM. The resulting vegetation was then compared with the a priori vegetation used in the first simulation. In a subsequent step, the RCM was rerun to yield a new climate more consistent with the simulated vegetation. Forcing conditions included orbital forcing, land-sea distribution, ice-sheet configuration, and atmospheric greenhouse gas concentrations representative for 44 ka BP. The results show a cold climate on the global scale, with global annual mean surface temperatures 5 degrees C colder than the modern climate. This is still significantly warmer than temperatures derived from the same model system for the Last Glacial Maximum (LGM). Regional, northern European climate is much colder than today, but still significantly warmer than during the LGM. Comparisons between the simulated climate and proxy-based sea-surface temperature reconstructions show that the results are in broad agreement, albeit with a possible cold bias in parts of the North Atlantic in summer. Given a prescribed restricted Marine Isotope Stage 3 ice-sheet configuration, with large ice-free regions in Sweden and Finland, the AOGCM and RCM model simulations produce a cold and dry climate in line with the restricted ice-sheet configuration during GS 12. The simulated temperature climate, with prescribed ice-free conditions in south-central Fennoscandia, is favourable for the development of permafrost, but does not allow local ice-sheet formation as all snow melts during summer.
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| 7. |
- Riehm, Mats, et al.
(författare)
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Optimization of winter road maintenance energy costs in Sweden : a critique of site specific frost warning techniques
- 2012
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Ingår i: Meteorological Applications. - : Wiley. - 1350-4827 .- 1469-8080. ; 19:4, s. 443-453
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Tidskriftsartikel (refereegranskat)abstract
- Frost formation on roads may cause slippery conditions and thereby increase the risk of accident occurrence. Roads are often treated with preventive operations using de-icing agents (e.g. road salt), which are ideally planned and performed prior to frost formation. The decisions on when and where to treat different road stretches with salt are based on meteorological measurements and forecasts. This paper investigates how uncertainties in meteorological measurements for frost prediction at road weather stations affect the efficiency of winter road maintenance. Different types of uncertainties and errors are discussed, together with potential solutions. The effects on winter road maintenance efficiency are discussed in terms of energy and cost. It was found that improvements in frost warning accuracy and reliability can lead to considerable savings and more efficient winter road maintenance.
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| 8. |
- Sardina, Gaetano, 1982, et al.
(författare)
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Broadening of Cloud Droplet Size Spectra by Stochastic Condensation: Effects of Mean Updraft Velocity and CCN Activation
- 2018
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Ingår i: Journals of the Atmospheric Sciences. - : American Meteorological Society. - 1520-0469 .- 0022-4928. ; 75:2, s. 451-467
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Tidskriftsartikel (refereegranskat)abstract
- The authors study the condensational growth of cloud droplets in homogeneous isotropic turbulence by means of a large-eddy simulation (LES) approach. The authors investigate the role of a mean updraft velocity and of the chemical composition of the cloud condensation nuclei (CCN) on droplet growth. The results show that a mean constant updraft velocity superimposed onto a turbulent field reduces the broadening of the droplet size spectra induced by the turbulent fluctuations alone. Extending the authors' previous results regarding stochastic condensation, the authors introduce a new theoretical estimation of the droplet size spectrum broadening that accounts for this updraft velocity effect. A similar reduction of the spectra broadening is observed when the droplets reach their critical size, which depends on the chemical composition of CCN. The analysis of the square of the droplet radius distribution, proportional to the droplet surface, shows that for large particles the distribution is purely Gaussian, while it becomes strongly non-Gaussian for smaller particles, with the left tail characterized by a peak around the haze activation radius. This kind of distribution can significantly affect the later stages of the droplet growth involving turbulent collisions, since the collision probability kernel depends on the droplet size, implying the need for new specific closure models to capture this effect.
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| 9. |
- Giorgini, Ludovico Theo, et al.
(författare)
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Non-Gaussian stochastic dynamical model for the El Niño southern oscillation
- 2022
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Ingår i: Physical Review Research. - : American Physical Society (APS). - 2643-1564. ; 4:2
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Tidskriftsartikel (refereegranskat)abstract
- A nonautonomous stochastic dynamical model approach is developed to describe the seasonal to interannual variability of the El Niño southern oscillation (ENSO). We determine the model coefficients by systematic statistical estimations using partial observations involving only sea surface temperature data. Our approach reproduces the observed seasonal phase locking and its uncertainty, as well as the highly non-Gaussian statistics of ENSO. Finally, we recover the intermittent time series of the hidden processes, including the thermocline depth and the wind bursts.
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| 10. |
- Capuano, Tonia Astrid, et al.
(författare)
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Oceanic realistic application of a microplastic biofouling model to the river discharge case
- 2024
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Ingår i: Environmental Pollution. - : Elsevier BV. - 0269-7491 .- 1873-6424. ; 359
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Tidskriftsartikel (refereegranskat)abstract
- Marine biofouling is considered one of the major biophysical processes influencing the vertical dynamics of plastic debris in seawater. We numerically implement, for the first time, this mechanism within a fine-resolution, regional model of the Tyrrhenian Sea, in order to simulate the dispersion of microplastics (MPs) released at the mouth of a highly polluting river. Four polymers and three particle sizes are used to quantify algal concentration influence on the trajectories, fates, and accumulation spots of the tracked MPs, by comparing 2002 winter and summer runs encompassing or not biofouling. Besides a marked seasonality for most of the MP types and radii tested, biofouling effects are prominently observed for only 2 polymers and particles bigger than 1μm. Thus, further realistic applications of the biofouling mechanism in oceanic circulation models are required to achieve a thorough assessment of its impact on plastic density within distinctive basins of the world seas.
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