MetNH3 Whim Bog Intercomparison Off-line ammonia metrology intercomparison

There is no regular quality assurance programme for ammonia passive samplers despite widespread use of these samplers across Europe and the rest of the world. In order to improve standards and begin to embed quality assurance in the measurement of ambient ammonia using passive samplers, within the EMRP MetNH3 project a passive sampler intercomparison was planned to enable side-by side exposure of the samplers to varying levels of ammonia in the field. From this experiment and in parallel the NPL CATFAC experiment (also within MetNH3), sufficient information and protocols could be developed. The method and infrastructure developed will then be available for future studies

Literature review on the performance of diffusive samplers for the measurement of ammonia in ambient air and emissions to air

The information in this document has formed the basis from which a new standard on measurements employing ammonia diffusive samplers by CEN TC264 WG11 'Ambient air - Diffusive samplers' is being developed and provides an open reference document for the ammonia passive sampling techniques

The future European standard to determine odour in ambient air by using field inspection

peer reviewedThis paper presents the methodologies to determine odour in ambient air by field inspection that will be a new European standard. The objective is to characterize the odour in a defined area. Without making a link with potential annoyance due to the presence of odours, the described methods propose the way to characterize an exposed environment. Two approaches are defined in the new standard: the grid method and the plume method. The grid method can be used determine the exposure to ambient odours in a defined area of study, using direct observation of recognizable odours in the field by human panel members. This method must be applied over a sufficiently long period of time (6 or 12 months) to be representative for the meteorological conditions of that location. The result is the distribution of the frequency of exposure to odours within the assessment area. The plume method can be used to determine the extent of detectable and recognizable odours from a specific source using direct observation in the field by human panel members under specific meteorological conditions

Review of the Application of Diffusive Samplers for the Measurement of Nitrogen Dioxide in Ambient Air in the European Union

A number of diffusive samplers that are used for longer-term monitoring of nitrogen dioxide in the European Union were subjected to a review of their use and performance characteristics. The information collected was used to evaluate the capacity of diffusive samplers for monitoring the European Union annual limit value of 40 µg.m-3 and to draft a proposal method for monitoring nitrogen dioxide in ambient air using diffusive samplers for later standardisation by the CEN Technical Committee 264 ¿Air Quality¿ Working Group 11 ¿Diffusive Samplers¿. A bibliographic review was carried out to determine the availability of validation data for these samplers, their capacity to meet the data quality objectives for indicative and/or fixed measurements of the European Directive, the possibility for users to analyse the samplers and their current use throughout the European Union for measuring ambient air quality. Two tubes-type samplers and a radial sampler were found to be used throughout the European Union. Based on the findings of the review it was concluded only for tube-type samplers based on the application of triethanolamine as the sorbent sufficient information was available to underpin its potential for meeting European Union data quality objectives, at the least, for indicative measurements of nitrogen dioxide in ambient air.JRC.H.4-Transport and air qualit

Swiss tree rings reveal warm and wet summers during medieval times

We present a 1200 year drought reconstruction for the European Alpine region based on carbon isotope variations of tree rings from living larch trees and historic timber. The carbon isotope fractionation at the study site is sensitive to summer precipitation, temperature, and irradiance, resulting in a stable and high correlation with a drought index for interannual to decadal frequencies and possibly beyond (r(2)=0.58 for 1901-2004, July/August). When combining this information with maximum latewood density-derived summer temperature, a strongly reduced occurrence of summer droughts during the warm A.D. 900-1200 period is evident, coinciding with the Medieval Climate Anomaly (MCA), with a shift to colder and drier conditions for the subsequent centuries. The warm-wet MCA contrasts strongly with the climate of the drought-prone warm phase of the recent decades, indicating different forcing mechanism for these two warm periods and pointing to beneficial conditions for agriculture and human well-being during the MCA in this region

Path integration controls nest-plume following in desert ants

The desert ant Cataglyphis fortis is equipped with sophisticated navigational skills for returning to its nest after foraging [1, 2]. The ant's primary means for long-distance navigation is path integration, which provides a continuous readout of the ant's approximate distance [3] and direction [4] from the nest [5]. The nest is pinpointed with the aid of visual [6–8] and olfactory landmarks [9–11]. Similar landmark cues help ants locate familiar food sites. Ants on their outward trip will position themselves so that they can move upwind using odor cues to find food [12]. Here we show that homing ants also move upwind along nest-derived odor plumes to approach their nest. The ants only respond to odor plumes if the state of their path integrator tells them that they are near the nest. This influence of path integration is important because we could experimentally provoke ants to follow odor plumes from a foreign, conspecific nest and enter that nest. We identified CO2 as one nest-plume component that can by itself induce plume following in homing ants. Taken together, the results suggest that path-integration information enables ants to avoid entering the wrong nest, where they would inevitably be killed by resident ants