Mapping Bio-CO2 and Wind Resources for Decarbonized Steel, E-Methanol and District Heat Production in the Bothnian Bay

Hydrogen is a versatile feedstock for various chemical and industrial processes, as well as an energy carrier. Dedicated hydrogen infrastructure is envisioned to conceptualize in hydrogen valleys, which link together the suppliers and consumers of hydrogen, heat, oxygen, and electricity. One potential hydrogen valley is the Bay of Bothnia, located in the northern part of the Baltic Sea between Finland and Sweden. The region is characterized as having excellent wind power potential, a strong forest cluster with numerous pulp and paper mills, and significant iron ore and steel production. The study investigates the hydrogen-related opportunities in the region, focusing on infrastructural requirements, flexibility, and co-operation of different sectors. The study found that local wind power capacity is rapidly increasing and will eventually enable the decarbonization of the steel sector in the area, along with moderate Power-to-X implementation. In such case, the heat obtained as a by-product from the electrolysis of hydrogen would greatly exceed the combined district heat demand of the major cities in the area. To completely fulfil its district heat demand, the city of Oulu was simulated to require 0.5–1.2 GW of electrolyser capacity, supported by heat pumps and optionally with heat storages.

Communities Beyond Society: Divergence of Local Prehistories on the Bothnian Arc, Northern Europe

This article presents a comparison of material records of two nearby regions on the coast of the Bothnian Bay. The timeframe is 5300–2000 BCE. The focus is on regional differences, which indicate a schizmogenesis of communal identities. The study calls for a reorientation of research concerning Fennoscandian prehistory. More attention should be paid to localized prehistories. It is argued that when prehistoric society is used as a fundamental group category, especially in the context of forager communities, the modern concept of state society distorts the underlying framework. Focusing on the regional level by constructing local prehistoric narratives limits the anachronistic effect and allows the proliferation of local communal identities. Such local prehistories, when collated and compared, offer a pathway to understanding prehistoric stateless societies, which are misrepresented by simplistic material cultural zones and the inherent homogeny ingrained within the concept of society. In this paper, the analysis is focused on practices representing local traditions. Two divergent themes that arise from the local prehistoric narratives are the Late Mesolithic use of local stone materials and regional changes in Neolithic dwelling forms.

Landfast sea ice in the Bothnian Bay (Baltic Sea) as a temporary storage compartment for greenhouse gases

Although studies of biogeochemical processes in polar sea ice have been increasing, similar research on relatively warm low-salinity sea ice remains sparse. In this study, we investigated biogeochemical properties of the landfast sea ice cover in the brackish Bothnian Bay (Northern Baltic Sea) and the possible role of this sea ice in mediating the exchange of greenhouse gases, including carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) across the water column–sea ice–atmosphere interface. Observations of total alkalinity and dissolved inorganic carbon in both landfast sea ice and the water column suggest that the carbonate system is mainly driven by salinity. While high CH4 and N2O concentrations were observed in both the water column (up to 14.3 and 17.5 nmol L–1, respectively) and the sea ice (up to 143.6 and 22.4 nmol L–1, respectively), these gases appear to be enriched in sea ice compared to the water column. This enrichment may be attributable to the sea ice formation process, which concentrates impurities within brine. As sea ice temperature and brine volume decrease, gas solubility decreases as well, promoting the formation of bubbles. Gas bubbles originating from underlying sediments may also be incorporated within the ice cover and contribute to the enrichment in sea ice. The fate of these greenhouse gases within the ice merits further research, as storage in this low-salinity seasonal sea ice is temporary.

Temperature and Humidity in the Base-floors of Three Northern Finnish Churches Containing 17th–19th-century Burials

Natural mummification occurs in various favorable conditions. Cold environments have produced mummified human remains in northern Finland. These remains buried under the church floors mummified naturally probably through a process resembling freeze-drying. This chapter explores the conditions that led to the mummification of dozens and potentially hundreds of human remains. To conduct our study, we installed logging temperature and humidity measuring devices under the floors of three churches located by the shore of Bothnian Bay in northern Finland. Even our preliminary results show that the humidity and temperature conditions differ between these churches. It is also clear that relative humidity remains very high under the floors of each church. It appears that mummification has occurred in almost “cellar like” conditions. The preservation process was probably aided by the loose laid constructions allowing the air to freely move in the graves carrying the moisture from the remains.

Tracing anthropogenic sources of Tantalum and Niobium in Bothnian Bay sediments, Sweden

Purpose This study aims to evaluate temporal trends of Tantalum (Ta) and Niobium (Nb) concentrations in northern Baltic Sea sediments with focus on the potential impact from the Rönnskär sulfide ore smelter, located 15 km east of Skellefteå in northern Sweden. The potential of Ta or Nb to serve as tracers for environmental pollution caused by the electronic waste is compared. Lastly, correlations between Ta and Nb concentrations and those of major redox elements are investigated. Methods A 35-cm-deep core was collected in the harbor bay (Kallholmsfjärden) outside of the smelter. A secondary 6-m-deep sediment core was collected in the deep Bothnian Bay for comparative purposes. Element screening analysis was conducted the using ICP-SFMS for the Kallhomsfjärden core and a combination of ICP-SFMS and ICP-OES for the Bothnian Bay core. In the final analysis, a 5-step sequential extraction technique was preformed to allow for better prediction of the fate and mobility of Ta and Nb. Results and discussion In the vicinity of the smelter, Ta concentration increases from 0.42 to 3.8 ppm from the time coinciding with the beginning of electronic waste processing. Conversely, Nb concentration remained stable at background levels throughout the core at 6.33 ± 0.78 ppm. The Nb/Ta ratio thus changed from 14.5 to 1.7, reflecting an increase of anthropogenic input of Ta into the bay sediments. In the pre-industrial part of the sediment, concentrations of both elements follow concentration of aluminosilicates in the core. In recent sediments, however, the anthropogenic Ta exhibits an association with hydrous ferric oxides (HFOs) and organic matter. Conclusions Notable increases in Ta concentrations began following the beginning of scrap metal and electronic waste processing at the Rönnskär smelter. Anthropogenic Ta introduced in the upper portion of the sediment and are more associated with HFOs and organic material than natural Ta seen in the deeper parts of the core where detrital Ta is most common. Niobium was not affected by the Rönnskär smelter and displayed no notable change to the preindustrial background.

Baltic Sea sediments record anthropogenic loads of Cd, Pb, and Zn

The unsustainable settlement and high industrialization around the catchment of the Baltic Sea has left records of anthropogenic heavy metal contamination in Baltic Sea sediments. Here, we show that sediments record post-industrial and anthropogenic loads of Cd, Zn, and Pb over a large spatial scale in the Baltic Sea. We also demonstrate that there is a control on the accumulation of these metals in relation to oxic/anoxic conditions of bottom waters. The total concentrations of Cd, Zn, and Pb were obtained with the near-total digestion method in thirteen cores collected from the Bothnian Bay, the Bothnian Sea, and the west and central Baltic Proper. The lowest average concentrations of Cd, Zn, and Pb were observed in Bothnian Bay (0.4, 125, 40.2 mg kg−1 DW, respectively). In contrast, the highest concentrations were observed in the west Baltic Proper (5.5, 435, and 56.6 mg kg−1 DW, respectively). The results indicate an increasing trend for Cd, Zn, and Pb from the early nineteenth century until the 1970s, followed by a decrease until 2000–2008. However, surface sediments still have concentrations above the pre-industrial values suggested by the Swedish EPA (Cd is 0.2, Zn is 85, and Pb is 31 mg kg−1 DW). The results also show that the pre-industrial Cd, Zn, and Pb concentrations obtained from 3 cores with ages < 1500 B.C. were 1.8, 1.7, and 1.2 times higher, respectively, than the pre-industrial values suggested by the Swedish EPA. To conclude, accumulations of metals in the Baltic Sea are governed by anthropogenic load and the redox conditions of the environment. The significance of correct environmental governance (measures) can be illustrated with the reduction in the pollution of Pb, Zn, and Cd within the Baltic Sea since the 1980s.

Simulation-Based Assessment of the Operational Performance of the Finnish–Swedish Winter Navigation System

This article presents a discrete event simulation-based approach for assessing the operating performance of the Finnish–Swedish Winter Navigation System (FSWNS) under different operating scenarios. Different operating scenarios are specified in terms of ice conditions, the volume of maritime traffic, number of icebreakers (IBs), and regulations such as the Energy Efficiency Design Index (EEDI). Considered performance indicators include transport capacity, number of instances of icebreaker (IB) assistance, and IB waiting times. The approach is validated against real-world data on maritime traffic in the Bothnian Bay. In terms of the number of ship arrivals per port, indicating the transport capacity of the FSWNS, the simulation agrees well with the data. In terms of the number of instances of IB assistance and IB waiting times per port, the standard deviations between the mean of 35 independent simulation runs and the data are 13% and 18%, respectively. A sensitivity analysis indicates that the simulated number of instances of IB assistance and IB waiting times is particularly sensitive to assumptions concerning the presence of brash ice channels. Case studies indicate that, unless the number of IBs is increased, the EEDI regulations may result in a significant increase in both the number of instances of IB assistance and the cumulated IB waiting times.

Winter atmospheric boundary layer observations over sea ice in the coastal zone of the Bothnian Bay (Baltic Sea)

The Hailuoto Atmospheric Observations over Sea ice (HAOS) campaign took place at the westernmost point of Hailuoto island (Finland) between 27 February and 2 March 2020. The aim of the campaign was to obtain atmospheric boundary layer (ABL) observations over seasonal sea ice in the Bay of Bothnia. Throughout 4 days both fixed-wing and quad-propeller rotorcraft unmanned aerial vehicles (UAV) were deployed over the sea ice to measure the properties of the lower ABL and to obtain accompanying high-resolution aerial photographs of the underlying ice surface. Additionally, a 3D sonic anenometer, an automatic weather station and a Halo Doppler lidar were installed on the shore to collect meteorological observations. During the UAV flights, measurements of temperature, relative humidity and atmospheric pressure were collected at 4 different altitudes between 25 m and 100 m, over an area of ~ 1.5 km2 of sea ice, located 1.1–1.3 km offshore from the Hailuoto Marjaniemi pier, together with orthomosaic maps of the ice surface below. Altogether the obtained dataset consists of 27 meteorological flights, 4 photogrammetry missions and continuous measurements of atmospheric properties from ground-based stations located at the coast. The acquired observations have been quality controlled and post processed and are available through the PANGAEA repository (https://doi.pangaea.de/10.1594/PANGAEA.918823, Wenta et al., 2020).