Grain Surface Models and Data for Astrochemistry

AbstractThe cross-disciplinary field of astrochemistry exists to understand the formation, destruction, and survival of molecules in astrophysical environments. Molecules in space are synthesized via a large variety of gas-phase reactions, and reactions on dust-grain surfaces, where the surface acts as a catalyst. A broad consensus has been reached in the astrochemistry community on how to suitably treat gas-phase processes in models, and also on how to present the necessary reaction data in databases; however, no such consensus has yet been reached for grain-surface processes. A team of ∼25 experts covering observational, laboratory and theoretical (astro)chemistry met in summer of 2014 at the Lorentz Center in Leiden with the aim to provide solutions for this problem and to review the current state-of-the-art of grain surface models, both in terms of technical implementation into models as well as the most up-to-date information available from experiments and chemical computations. This review builds on the results of this workshop and gives an outlook for future directions

Inuvialuit traditional ecological knowledge of beluga whale ( Delphinapterus leucas

This paper documents Inuvialuit traditional ecological knowledge of beluga, including ecology and behavior, hunting techniques, and food preparation under changing climatic conditions in Tuktoyaktuk, NT. Beluga whale (Delphinapterus leucas) is an important food source for Inuvialuit in the western Canadian Arctic, a region that is experiencing dramatic climate change. Data were collected using semi-directed interviews with 17 Inuvialuit beluga harvesters and participant observation. The research found that Inuvialuit beluga harvesters possess detailed rational knowledge of beluga, particularly regarding hunting techniques and food preparation, both which are guided by a moral code about how to behave with respect to beluga. In terms of beluga ecology and behavior, Inuvialuit knowledge is limited to anecdotal reasoning drawing on generalized observations of beluga and the accounts of others. Inuvialuit are experiencing the effects of climate change, but seem to be coping thus far in the context of beluga harvesting but ongoing change in the region may increase the risks associated with hunting and preparing beluga in the future

The Determination of Ecological Quality in -Shallow Lakes. A Tested System (ECOFRAME) for Implementation of the European Water Framework Directive.

Abstract not availableJRC.H-Institute for environment and sustainability (Ispra

Response of Zooplankton to Nutrient Enrichment and Fish Predation in Shallow Lakes Along a European Climatic Gradient. A Pan-European Mesocosm Experiment.

Abstract not availableJRC.H-Institute for environment and sustainability (Ispra

Continental-Scale Patterns of Nutrient and Fish Effects on Shallow Wetland Lakes. Synthesis of a Pan-European International Mesocosm Experiment.

Abstract not availableJRC.H-Institute for environment and sustainability (Ispra

Responses of Phytoplankton to Fish Predation and Nutrient Loading in Shallow Lakes: a Pan-European Mesocosm Experiment.

Abstract not availableJRC.H-Institute for environment and sustainability (Ispra

Continental Scale Patterns of Nutrient and Fish Effects on Shallow Wetland Lakes. Introduction to a Pan-European International Mesocosm Experiment.

Abstract not availableJRC.H-Institute for environment and sustainability (Ispra

Factors controlling hydrochemical and trophic state variables in 86 shallow lakes in Europe

In order to disentangle the causes of variations in water chemistry among European shallow lakes, we performed standardised sampling programs in 86 lakes along a latitudinal gradient from southern Spain to northern Sweden. Lakes with an area of 0.1 to 27 000 ha and mean depth of 0.4–5.6 m located in low to high altitudes were investigated within the EC project ECOFRAME 1–4 times during June–October 2000–2001. Several variables like conductivity, alkalinity, abundance of submerged plants, concentrations of suspended solids, total nitrogen and phosphorus were latitude-dependent decreasing from south to north. Secchi depth, concentrations of total nitrogen, total phosphorus, suspended solids, and chlorophyll a correlated strongly with the presumed quality classes of the lakes. We came to the conclusion that the variability of shallow lakes in Europe is still mostly dependent on natural differences. Variables connected to lake morphometry, seasonality, basin geology and climate explained altogether nearly half of the total variability of lakes. The trophic state factor, describing mostly the human influence on lakes, was the strongest single factor responsible for nearly a quarter of the total variability of the studied European lakes [KEYWORDS: ecological status, European shallow lakes, hydrochemistry, latitude]

Continental-scale patterns of nutrient and fish effects on shallow lakes: synthesis of a pan-European mesocosm experiment

1. Results are analysed from 11 experiments in which effects of fish addition and nutrient loading on shallow lakes were studied in mesocosms. The experiments, five in 1998, six in 1999, were carried out in six lakes, distributed from Finland to southern Spain, according to a standard protocol. 2. Effects of the treatments on 29 standard chemical, phytoplankton and zooplankton variables are examined to assess the relative importance of bottom-up (nutrient enrichment) and top-down (fish predation) effects. For each year, the experiments in different locations are treated as replicates in a meta-analysis. Results of individual experiments are then compared in terms of the patterns of significant influences of nutrient addition and fish predation with these overall results (the baseline), 3. The overall meta-analysis gave consistent results across the 2 years, with nutrient loading influencing all of the chemical variables, and on average 31% of primary producer and 39% of zooplankton variables. In contrast, fish influenced none of the chemical variables, 11% of the primary producer and 44% of the zooplankton variables. Nutrient effects on the system were thus about three times greater than fish effects, although fish effects were not inconsiderable. 4. The relative importance of nutrients and fish in individual experiments often differed between years at the same location and effects deviated to varying degrees from the baseline. These deviations were treated as measures of consistency (predictability) of conclusions in repeat experiments. Consistency increased southwards and this is interpreted as a consequence of more variable annual weather northwards. 5. The influence of nutrient loading was greater southwards and this was probably manifested through naturally greater annual macrophyte abundance in warmer locations in consequence of the longer plant growing-season. There was no trend in the relative importance of fish effects with latitude but this may partly be an artefact of the simple fish community used. These findings suggest that nutrient control should be a greater priority than biomanipulation in the restoration of eutrophicated shall 6. Starting conditions affected the outcome of experiments. High initial concentrations of total phosphorus and planktonic chlorophyll a concentration (created by local conditions prior to the experiment) led to de-emphasis of the importance of nutrient loading in the experiment. [KEYWORDS: continental gradient ; fish ; meta-analysis ; nutrients ; weather variation]

Factors controlling hydrochemical and trophic state variables in 86 shallow lakes in Europe

In order to disentangle the causes of variations in water chemistry among European shallow lakes, we performed standardised sampling programs in 86 lakes along a latitudinal gradient from southern Spain to northern Sweden. Lakes with an area of 0.1 to 27 000 ha and mean depth of 0.4–5.6 m located in low to high altitudes were investigated within the EC project ECOFRAME 1–4 times during June–October 2000–2001. Several variables like conductivity, alkalinity, abundance of submerged plants, concentrations of suspended solids, total nitrogen and phosphorus were latitude-dependent decreasing from south to north. Secchi depth, concentrations of total nitrogen, total phosphorus, suspended solids, and chlorophyll a correlated strongly with the presumed quality classes of the lakes. We came to the conclusion that the variability of shallow lakes in Europe is still mostly dependent on natural differences. Variables connected to lake morphometry, seasonality, basin geology and climate explained altogether nearly half of the total variability of lakes. The trophic state factor, describing mostly the human influence on lakes, was the strongest single factor responsible for nearly a quarter of the total variability of the studied European lakes [KEYWORDS: ecological status, European shallow lakes, hydrochemistry, latitude