Atmospheric phenomena data processing and display

Several related efforts which deal with the analysis and display of data pertaining to various atmospheric phenomena are reported. Spectrometer data analysis, with refinements to the preexisting programs, is discussed. A discussion of a Monte Carlo simulation of a photon transfer problem is presented. Raw data gathered in the field by a high-flying U2 aircraft is usually pulse code modulated (PCM). Techniques to reduce the data into a computer-amenable format are described. Several utility programs and other work are outlined

Processing and display of atmospheric phenomenaa data

A series of technical efforts dealing with various atmospheric phenomena is described. Refinements to the Potential in an Electrostatic Cloud (PEC) model are discussed. The development of an Apple III graphics program, the NSSL Lightning Data Program and a description of data reduction procedures are examined. Several utility programs are also discussed

Application of the particle filter to tracking of fish in aquaculture research

The analysis of fish movement as an indicator of fish behaviour plays an important role in aquaculture research. Currently observations are carried out manually using video recordings. In this paper we describe a tracking system which can automatically detect and track two fish in a video sequence in a small aquaculture tank. The system is based on the particle filter tracking algorithm augmented by an adaptive partition scheme and using a Global Nearest Neighbour approach for data association. Results show that this method is sufficient for simple interactions where fish bypass each other without significant changes in velocity. However, more complex scenarios involving occlusions, loss of tracks and fish manoeuvres can cause ambiguity during data association

Wind-Tunnel Investigation of Perforated Split Flaps for Use as Dive Brakes on a Tapered NACA 23012 Airfoil

Aerodynamic characteristics of a tapered NACA 23012 airfoil with single and double perforated split flaps have been determined in the NACA 7- by 10-foot wind tunnel. Dynamic pressure surveys were made behind the airfoil at the approximate location of the tail in order to determine the extent and location of the wake for several of the flap arrangements. In addition, computations have been made of an application of perforated double split flaps for use as fighter brakes. The results indicated that single or double perforated split flaps may be used to obtain satisfactory dive control without undue buffeting effects and that single or double perforated split flaps may also be used as fighter brakes. The perforated split flaps had approximately the same effects on the aerodynamic and wake characteristics of the tapered airfoil as on a comparable rectangular airfoil

A first assessment of the sources of isoprene and monoterpene emissions from a short-rotation coppice Eucalyptus gunnii bioenergy plantation in the UK

Eucalyptus gunnii is a fast-growing, cold-tolerant tree species endemic to Tasmania that is suitable for growing as short-rotation coppice (SRC) plantations in the UK. Fast growing eucalypts such as E. gunnii could potentially deliver higher biomass yields with a superior calorific value for the domestic bioenergy market than other SRC plantation species such as willow or poplar. However, eucalypts are known emitters of biogenic volatile organic compounds (BVOC) like isoprene and monoterpenes. These compounds contribute to the formation of atmospheric pollutants such as ozone and secondary organic aerosols. An assessment of the sources of BVOCs during the lifecycle of a UK E. gunnii SRC plantation found the mean standardised emissions of isoprene and total monoterpenes from branches of juvenile foliage to be 7.50 μg C gdw−1 h−1 and 1.30 μg C gdw−1 h−1, respectively. The predominant monoterpene emitted was cis-β-ocimene. Isoprene emissions from the forest floor were extremely low but monoterpene emissions peaked at 50 μg C m−2 h−1. α-Pinene and d-limonene were the major components of the monoterpene emissions, with higher emissions correlated to the abundance of leaf litter. Both the magnitude and composition of monoterpene emissions from the forest floor varied during the SRC plantation life cycle, with the coppiced and regrowth stands of eucalyptus producing less emissions. The woodchip produced at harvesting emitted only trace levels of isoprene but substantial monoterpene emissions, up to 90 μg C m−2 h−1, predominately eucalyptol. Harvesting and resulting biomass chips may provide a short-lived concentrated source of BVOCs in winter at SRC plantations. Modelled annual emissions using MEGAN 2.1 (canopy emissions only) suggest that BVOC emissions from a UK E. gunnii SRC plantation are most abundant in summer, and that modelled annual isoprene and total monoterpenes emissions could be around 6.9 kg C ha−1 and 2.4 kg C ha−1 respectively, for a young plantation. Based on the very limited data, the per-hectare E. gunnii isoprene emissions are smaller than estimates for other SRC/SRF plantation species in the UK; the per-hectare monoterpene emissions are in the span of estimates for other plantation species

Global distribution of the cold-water coral Lophelia pertusa

Lophelia pertusa plays an important role as a major contributor to many cold-water coral reefs, supporting a high diversity of associated benthic and benthopelagic species. Due to the high sensitivity of L. pertusa to human activity, it has been classified as indicator species for Vulnerable Marine Ecosystems. However, the global spatial distribution of L. pertusa is far from well known. In this study, a database of L. pertusa presence data was compiled derived from the large number of L. pertusa occurrence records appearing in recent years. In conjunction with data layers covering a range of environmental drivers, habitat suitability for L. pertusa was predicted using the Random Forest approach. Suitable habitat for L. pertusa was predicted to occur primarily on continental margins, with the most suitable habitat likely to occur in the North East Atlantic and South Eastern United States of America. Aragonite saturation state, temperature and salinity were identified as the most important contributors to the habitat suitability model. Given the high vulnerability of reef-forming cold-water corals to anthropogenic impacts, habitat suitability models are critical in developing worldwide conservation and management strategies for biodiverse and biomass rich cold-water coral ecosystems

Rapid recovery following short-term acoustic disturbance in two fish species

ArticleNoise from human activities is known to impact organisms in a variety of taxa, but most experimental studies on the behavioural effects of noise have focused on examining responses associated with the period of actual exposure. Unlike most pollutants, acoustic noise is generally short-lived, usually dissipating quickly after the source is turned off or leaves the area. In a series of experiments, we use established experimental paradigms to examine how fish behaviour and physiology are affected, both during short-term (2 min) exposure to playback of recordings of anthropogenic noise sources and in the immediate aftermath of noise exposure. We considered the anti-predator response and ventilation rate of juvenile European eels (Anguilla anguilla), and ventilation rate of juvenile European seabass (Dicentrarchus labrax). As previously found, additional-noise exposure decreased eel anti-predator responses, increased startle latency and increased ventilation rate relative to ambient-noise-exposed controls. Our results show for the first time that those effects quickly dissipated; eels showed rapid recovery of startle responses and startle latency, and rapid albeit incomplete recovery of ventilation rate in the 2 min after noise cessation. Seabass in both laboratory and open-water conditions showed an increased ventilation rate during playback of additional noise compared to ambient conditions. However, within 2 min of noise cessation, ventilation rate showed complete recovery to levels equivalent to ambient-exposed control individuals. Care should be taken in generalizing these rapid-recovery results, as individuals might have accrued other costs during noise exposure and other species might show different recovery times. Nonetheless, our results from two different fish species provide tentative cause for optimism concerning recovery following short-duration noise exposure, and suggest that considering periods following noise exposures could be important for mitigation and management decisions.DefraNER