Search results for "climate"

Ultraviolet Imaging of Volcanic Plumes: A New Paradigm in Volcanology

2017

Ultraviolet imaging has been applied in volcanology over the last ten years or so. This provides considerably higher temporal and spatial resolution volcanic gas emission rate data than available previously, enabling the volcanology community to investigate a range of far faster plume degassing processes, than achievable hitherto. To date this has covered rapid oscillations in passive degassing through conduits and lava lakes, as well as puffing and explosions, facilitating exciting connections to be made for the first time between previously rather separate sub disciplines of volcanology. Firstly, there has been corroboration between geophysical and degassing datasets at ≈ 1 Hz e…

2021

Holocene climate in Central Europe was characterized by variations on millennial to decadal time scales. Speleothems provide the opportunity to study such palaeoclimate variability using high temporal resolution proxy records, and offer precise age models by U-series dating. However, the significance of proxy records from an individual speleothem is still a matter of debate, and limited sample availability often hampers the possibility to reproduce proxy records or to resolve spatial climate patterns. Here we present a palaeoclimate record based on four stalagmites from the Hüttenbläserschachthöhle (HBSH), western Germany. Two specimens cover almost the entire Holocene, with a short hiatus …

Subsurface swimming and stationary diving are metabolically cheap in adult Pacific walruses (Odobenus rosmarus divergens).

2021

ABSTRACT Walruses rely on sea-ice to efficiently forage and rest between diving bouts while maintaining proximity to prime foraging habitat. Recent declines in summer sea ice have resulted in walruses hauling out on land where they have to travel farther to access productive benthic habitat while potentially increasing energetic costs. Despite the need to better understand the impact of sea ice loss on energy expenditure, knowledge about metabolic demands of specific behaviours in walruses is scarce. In the present study, 3 adult female Pacific walruses (Odobenus rosmarus divergens) housed in professional care participated in flow-through respirometry trials to measure metabolic rates while…

2018

Volcanoes are a significant halogen source to the atmosphere. After water, carbon dioxide and sulfur compounds, halogens are often the most abundant gases in volcanic plumes. In the past, less attention was given to the heavy halogens bromine and iodine. However, the discovery of bromine monoxide (BrO) in volcanic plumes led to new interest especially in volcanic bromine chemistry and its impact on atmospheric processes. The BrO detection came along with advances in volcanic remote sensing techniques, in particular, robust DOAS applications and the possibility of continuous measurements by automated instruments located at safe distances from the volcano. As one of the consequences, the volc…

Measurements of volcanic SO2 and CO2 fluxes by combined DOAS, Multi-GAS and FTIR observations: a case study from Turrialba and Telica volcanoes

2014

Over the past few decades, substantial progress has been made to overcome the technical difficulties of continuously measuring volcanic SO2 emissions. However, measurements of CO2 emissions still present many difficulties, partly due to the lack of instruments that can directly measure CO2 emissions and partly due to its strong atmospheric background. In order to overcome these difficulties, a commonly taken approach is to combine differential optical absorption spectroscopy (DOAS) by using NOVAC scan-DOAS instruments for continuous measurements of crateric SO2 emissions, and electrochemical/NDIR multi-component gas analyser system (multi-GAS) instruments for measuring CO2/SO2 ratios of exc…

Potential Impact of Global Climate Change on Species Richness of Long-Distance Migrants

2003

Little evidence exists demonstrating that global climate change leads to systematic changes in the struc- ture of ecological communities. For avian communities, one would expect warmer winters to lead to declines in numbers of long-distance migrants if resident birds benefit from warmer winters and impose increasing competi- tive pressure on migrants. To study the potential influence of global climate change on long-distance migrants, we correlated the number of all species of land birds and the number and proportion of long-distance migrants, short- distance migrants, and residents in 595 grid cells across Europe. We used mean temperature of the coldest month, mean spring temperature, and …

Rapid recovery of invertebrate communities after ecological restoration of boreal mires

2015

Mire degradation due to drainage for forestry results in the loss of mire specialist species. To halt the loss in biodiversity, ecological restoration is needed and already implemented. However, a major challenge in ecological restoration is whether actions taken have the desired outcome. Key abiotic and biotic conditions for the successful restoration of invertebrate communities can be identified by testing the “Field of Dreams” hypothesis, which postulates that if a habitat is successfully restored, species will return. This study was conducted in nine boreal mires located in Eastern Finland, 1–3 years after restoration. Parts of each mire were drained for forestry during the 1960s and 19…

Maritime antarctic lakes as sentinels of climate change

2012

Remote lakes, such as lakes from the Maritime Antarctica, can be used as sentinels of climate change, because they are mostly free of direct anthropogenic pressures, and they experience climate change as a main stressor capable of modifying the ecosystem structure and function. In this paper, the content of a lecture that has been presented at the First Conference of Lake Sustainability, which has been centred in our studies on lakes from Byers Peninsula (Maritime Antarctica), are summarized. These included physical, chemical and biological studies of these lakes and other freshwater ecosystems, which highlighted the relevance of biotic interactions for these ecosystems and its sensibility …

Pampa Biome Environmental Particularities Regarding to Energy Balance

2020

Ecosystem evapotranspiration (ET) has been quantified around the world by different methodologies to understand the energy balance, especially to control the evolution of climate change. It is known that the vegetation of the pampa biome is natural grasslands, it has a large variety of species (flora and fauna), however is it different in the environmental aspects related to the energy balance when compared to the grassland cultivated? In this study the objective was to analyze the environmental differences of the Pampa Biome related to the energy balance in comparison with the pastures cultivated in Barrax, Spain. In the first one the minimum daily ET is 0.99 mm/day, while in the second is…

Conservation of threatened habitat types under future climate change – Lessons from plant-distribution models and current extinction trends in southe…

2015

A higher risk of future range losses as a result of climate change is expected to be one of the main drivers of extinction trends in vascular plants occurring in habitat types of high conservation value. Nevertheless, the impact of the climate changes of the last 60 years on the current distribution and extinction patterns of plants is still largely unclear. We applied species distribution models to study the impact of environmental variables (climate, soil conditions, land cover, topography), on the current distribution of 18 vascular plant species characteristic of three threatened habitat types in southern Germany: (i) xero-thermophilous vegetation, (ii) mesophilous mountain grasslands (…