scholarly journals Adaptive strategies of high-flying migratory hoverflies in response to wind currents

2020 ◽  
Vol 287 (1928) ◽  
pp. 20200406 ◽  
Author(s):  
Boya Gao ◽  
Karl R. Wotton ◽  
Will L. S. Hawkes ◽  
Myles H. M. Menz ◽  
Don R. Reynolds ◽  
...  
Keyword(s):  
High Altitude ◽  
Ground Level ◽  
Adaptive Strategies ◽  
Sufficient Accuracy ◽  
Wind Drift ◽  
Complex Behaviour ◽  
Complex Orientation ◽  
Prevailing Direction ◽  
The Uk ◽  
Wind Currents

Large migrating insects, flying at high altitude, often exhibit complex behaviour. They frequently elect to fly on winds with directions quite different from the prevailing direction, and they show a degree of common orientation, both of which facilitate transport in seasonally beneficial directions. Much less is known about the migration behaviour of smaller (10–70 mg) insects. To address this issue, we used radar to examine the high-altitude flight of hoverflies (Diptera: Syrphidae), a group of day-active, medium-sized insects commonly migrating over the UK. We found that autumn migrants, which must move south, did indeed show migration timings and orientation responses that would take them in this direction, despite the unfavourability of the prevailing winds. Evidently, these hoverfly migrants must have a compass (probably a time-compensated solar mechanism), and a means of sensing the wind direction (which may be determined with sufficient accuracy at ground level, before take-off). By contrast, hoverflies arriving in the UK in spring showed weaker orientation tendencies, and did not correct for wind drift away from their seasonally adaptive direction (northwards). However, the spring migrants necessarily come from the south (on warm southerly winds), so we surmise that complex orientation behaviour may not be so crucial for the spring movements.

An aerial netting study of insects migrating at high altitude over England

2004 ◽  
Vol 94 (2) ◽  
pp. 123-136 ◽  
Author(s):  
J.W. Chapman ◽  
D.R. Reynolds ◽  
A.D. Smith ◽  
E.T. Smith ◽  
I.P. Woiwod
Keyword(s):  
Global Warming ◽  
High Altitude ◽  
North Sea ◽  
Ground Level ◽  
Diel Periodicity ◽  
Tethered Balloon ◽  
Extensive Survey ◽  
Economic Significance ◽  
Large Populations ◽  
The Uk

AbstractDay and night sampling of windborne arthropods at a height of 200 m above ground was undertaken at Cardington, Bedfordshire, UK, during July 1999, 2000 and 2002, using a net supported by a tethered balloon. The results from this study are compared with those from the classic aerial sampling programmes carried out by Hardy, Freeman and colleagues over the UK and North Sea in the 1930s. In the present study, aerial netting was undertaken at night as well as daytime, and so the diel periodicity of migration could be investigated, and comparisons made with the results from Lewis and Taylor’s extensive survey of flight periodicity near ground level. In some taxa with day-time emigration, quite large populations could continue in high-altitude flight after dark, perhaps to a previously underrated extent, and this would greatly increase their potential migratory range. Any trend towards increases in night temperatures, associated with global warming, would facilitate movements of this type in the UK. Observations on the windborne migration of a variety of species, particularly those of economic significance or of radar-detectable size, are briefly discussed.

scholarly journals Simultaneous generalized and low-layer SCIDAR turbulence profiles at san pedro mártir observatory

2019 ◽  
Vol 490 (1) ◽  
pp. 1397-1405 ◽  
Author(s):  
R Avila ◽  
O Valdés-Hernández ◽  
L J Sánchez ◽  
I Cruz-González ◽  
J L Avilés ◽  
...  
Keyword(s):  
High Altitude ◽  
Wind Direction ◽  
Close Agreement ◽  
Baja California ◽  
Ground Level ◽  
Combined Effect ◽  
Moderate Altitude ◽  
San Pedro ◽  
Simultaneous Measurements

ABSTRACT We present optical turbulence profiles obtained with a Generalized SCIDAR (G-SCIDAR) and a low-layer SCIDAR (LOLAS) at the Observatorio Astronómico Nacional in San Pedro Mártir (OAN-SPM), Baja California, Mexico, during three observing campaigns in 2013, 2014, and 2015. The G-SCIDAR delivers profiles with moderate altitude-resolution (a few hundred metres) along the entire turbulent section of the atmosphere, while the LOLAS gives high altitude resolution (on the order of tens of metres) but only within the first few hundred metres. Simultaneous measurements were obtained on 2014 and allowed us to characterize in detail the combined effect of the local orography and wind direction on the turbulence distribution close to the ground. At the beginning of several nights, the LOLAS profiles show that turbulence peaks between 25 and 50 m above the ground, not at ground level as was expected. The G-SCIDAR profiles exhibit a peak within the first kilometre. In 55 per cent and 36 per cent of the nights stable layers are detected between 10 and 15 km and at 3 km, respectively. This distribution is consistent with the results obtained with a G-SCIDAR in 1997 and 2000 observing campaigns. Statistics computed with the 7891 profiles that have been measured at the OAN-SPM with a G-SCIDAR in 1997, 2000, 2014, and 2015 campaigns are presented. The seeing values calculated with each of those profiles have a median of 0.79, first and third quartiles of 0.51 and 1.08 arcsec, which are in close agreement with other long term seeing monitoring performed at the OAN-SPM.

scholarly journals Modelling surface ozone during the 2003 heat-wave in the UK

2010 ◽  
Vol 10 (16) ◽  
pp. 7963-7978 ◽  
Author(s):  
M. Vieno ◽  
A. J. Dore ◽  
D. S. Stevenson ◽  
R. Doherty ◽  
M. R. Heal ◽  
...  
Keyword(s):  
Heat Wave ◽  
Transport Model ◽  
Temporal Structure ◽  
Surface Ozone ◽  
Wrf Model ◽  
Ground Level ◽  
Reanalysis Data ◽  
Diurnal Cycles ◽  
Spatio Temporal ◽  
The Uk

Abstract. The EMEP4UK modelling system is a high resolution (5×5 km2) application of the EMEP chemistry-transport model, designed for scientific and policy studies in the UK. We demonstrate the use and performance of the EMEP4UK system through the study of ground-level ozone (O3) during the extreme August 2003 heat-wave. Meteorology is generated by the Weather Research and Forecast (WRF) model, nudged every six hours with reanalysis data. We focus on SE England, where hourly average O3 reached up to 140 ppb during the heat-wave. EMEP4UK accurately reproduces elevated O3 and much of its day-to-day variability during the heat-wave. Key O3 precursors, nitrogen dioxide and isoprene, are less well simulated, but show generally accurate diurnal cycles and concentrations to within a factor of ~2–3 of observations. The modelled surface O3 distribution has an intricate spatio-temporal structure, governed by a combination of meteorology, emissions and photochemistry. A series of sensitivity runs with the model are used to explore the factors that influenced O3 levels during the heat-wave. Various factors appear to be important on different days and at different sites. Ozone imported from outside the model domain, especially the south, is very important on several days during the heat-wave, contributing up to 85 ppb. The effect of dry deposition is also important on several days. Modelled isoprene concentrations are generally best simulated if isoprene emissions are changed from the base emissions: typically doubled, but elevated by up to a factor of five on one hot day. We found that accurate modelling of the exact positions of nitrogen oxide and volatile organic compound plumes is crucial for the successful simulation of O3 at a particular time and location. Variations in temperature of ±5 K were found to have impacts on O3 of typically less than ±10 ppb.

scholarly journals Flight periodicity and the vertical distribution of high-altitude moth migration over southern Britain

2009 ◽  
Vol 99 (5) ◽  
pp. 525-535 ◽  
Author(s):  
C.R. Wood ◽  
D.R. Reynolds ◽  
P.M. Wells ◽  
J.F. Barlow ◽  
I.P. Woiwod ◽  
...  
Keyword(s):  
Vertical Distribution ◽  
High Altitude ◽  
Light Trapping ◽  
Radar Data ◽  
Study Approach ◽  
Autographa Gamma ◽  
Combining Data ◽  
The Uk ◽  
First Time ◽  
The Vertical Distribution

AbstractThe continuous operation of insect-monitoring radars in the UK has permitted, for the first time, the characterization of various phenomena associated with high-altitude migration of large insects over this part of northern Europe. Previous studies have taken a case-study approach, concentrating on a small number of nights of particular interest. Here, combining data from two radars, and from an extensive suction- and light-trapping network, we have undertaken a more systematic, longer-term study of diel flight periodicity and vertical distribution of macro-insects in the atmosphere. Firstly, we identify general features of insect abundance and stratification, occurring during the 24-hour cycle, which emerge from four years' aggregated radar data for the summer months in southern Britain. These features include mass emigrations at dusk and, to a lesser extent, at dawn and daytime concentrations associated with thermal convection. We then focus our attention on the well-defined layers of large nocturnal migrants that form in the early evening, usually at heights of 200–500 m above ground. We present evidence from both radar and trap data that these nocturnal layers are composed mainly of noctuid moths, with species such as Noctua pronuba, Autographa gamma, Agrotis exclamationis, A. segetum, Xestia c-nigrum and Phlogophora meticulosa predominating.

scholarly journals The changing oxidizing environment in London – trends in ozone precursors and their contribution to ozone production

2014 ◽  
Vol 14 (2) ◽  
pp. 1287-1316 ◽  
Author(s):  
E. von Schneidemesser ◽  
M. Vieno ◽  
P. S. Monks
Keyword(s):  
Nitrogen Oxides ◽  
Tropospheric Ozone ◽  
Urban Areas ◽  
Harmful Effect ◽  
Ground Level ◽  
Ozone Production ◽  
Population Exposure ◽  
High Concentrations ◽  
Mitigation Effort ◽  
The Uk

Abstract. Ground-level ozone is recognized to be a threat to human health (WHO, 2003), have a deleterious impact on vegetation (Fowler et al., 2009), is also an important greenhouse gas (IPCC, 2007) and key to the oxidative ability of the atmosphere (Monks et al., 2009). Owing to its harmful effect on health, much policy and mitigation effort has been put into reducing its precursors – the nitrogen oxides (NOx) and non-methane volatile organic compounds (NMVOCs). The non-linear chemistry of tropospheric ozone formation, dependent mainly on NOx and NMVOC concentrations in the atmosphere, makes controlling tropospheric ozone complex. Furthermore, the concentration of ozone at any given point is a complex superimposition of in-situ produced or destroyed ozone and transported ozone on the regional and hemispheric-scale. In order to effectively address ozone, a more detailed understanding of its origins is needed. Here we show that roughly half (5 μg m−3) of the observed increase in urban (London) ozone (10 μg m−3) in the UK from 1998 to 2008 is owing to factors of local origin, in particular, the change in NO : NO2 ratio, NMVOC : NOx balance, NMVOC speciation, and emission reductions (including NOx titration). In areas with previously higher large concentrations of nitrogen oxides, ozone that was previously suppressed by high concentrations of NO has now been "unmasked", as in London and other urban areas of the UK. The remaining half (approximately 5 μg m−3) of the observed ozone increase is attributed to non-local factors such as long-term transport of ozone, changes in background ozone, and meteorological variability. These results show that a two-pronged approach, local action and regional-to-hemispheric cooperation, is needed to reduce ozone and thereby population exposure, which is especially important for urban ozone.

scholarly journals Modelling surface ozone during the 2003 heat wave in the UK

2009 ◽  
Vol 9 (5) ◽  
pp. 19509-19544 ◽  
Author(s):  
M. Vieno ◽  
A. J. Dore ◽  
D. S. Stevenson ◽  
R. Doherty ◽  
M. R. Heal ◽  
...  
Keyword(s):  
Heat Wave ◽  
Transport Model ◽  
Temporal Structure ◽  
Surface Ozone ◽  
Wrf Model ◽  
Ground Level ◽  
Reanalysis Data ◽  
Diurnal Cycles ◽  
The Uk ◽  
Surface O3

Abstract. A high resolution (5×5 km2) UK-scale chemistry-transport model (EMEP4UK) is used to study ground-level ozone (O3) during the August 2003 heat-wave. Meteorology is generated by the Weather Research and Forecast (WRF) model, nudged every six hours with reanalysis data. We focus on SE England, where hourly average O3 reached up to 140 ppb during the heat-wave. EMEP4UK accurately reproduces observed annual and diurnal cycles of surface O3 at urban and rural sites. Elevated O3 and much of its day-to-day variability during the heat-wave are well captured. Key O3 precursors, nitrogen dioxide and isoprene (C5H8), are less well simulated, but show generally accurate diurnal cycles and concentrations to within a factor of ~2–3 of observations. The modelled surface O3 distribution has an intricate spatio-temporal structure, governed by a combination of meteorology, emissions and photochemistry. A series of sensitivity runs with the model are used to explore the factors that influenced O3 levels during the heat-wave. Various factors appear to be important on different days and at different sites. Ozone imported from outside the model domain, especially the south, is very important on several days during the heat-wave, contributing up to 85 ppb. Dry deposition of O3, when completely switched off, elevated simulated O3 by up to 50 ppb, and this may have been an important factor on several days. Modelled C5H8 concentrations are generally best simulated if C5H8 emissions are changed from the base emissions: typically doubled, but elevated by up to a factor of five on some days. Accurately modelling the exact positions of individual plumes of anthropogenically emitted nitrogen oxides and volatile organic compounds is crucial for the successful simulation of O3 at a particular time and location. Variations in surface temperature of ±5 K were found to have impacts on O3 of typically less than ±10 ppb.

scholarly journals Comparisons of spectrally resolved nightglow emission locally simulated with space and ground level observations

2020 ◽  
Vol 10 ◽  
pp. 21 ◽  
Author(s):  
Christophe Bellisario ◽  
Pierre Simoneau ◽  
Philippe Keckhut ◽  
Alain Hauchecorne
Keyword(s):  
High Altitude ◽  
Large Scale ◽  
Molecular Diffusion ◽  
Ground Level ◽  
Atmospheric Tides ◽  
Emission Rates ◽  
Spectral Radiation ◽  
Volume Emission ◽  
Spectrally Resolved ◽  
The Impact

A mesospheric model of the airglow emission is developed to recover the night variations observed at ground level. The model is based on a 1D vertical photochemical model, including the photodissociation and heating processes. The spectral radiation is calculated at high altitude and propagated through the atmosphere to the ground. We also include short scale vertical dynamic such as turbulences and the molecular diffusion. Simulations reveal realistic emissions when compared with space observations. In addition, we estimate the impact of changes associated with parameterized atmospheric tides. The comparison with observations is performed over high altitude and ground level. We confront the model outputs at high altitude with satellite observations (SABER and GOMOS) and the simulations propagated at ground level are compared to local measurements campaigns performed in France and India. Biases between observed and simulated radiances and volume emission rates are suspected to be due to the impact of gravity waves or the large scale dynamic.

scholarly journals Understanding breastfeeding behaviours: a cross-sectional analysis of associated factors in Ireland, the United Kingdom and Australia

2020 ◽  
Vol 15 (1) ◽  
Author(s):  
Danielle Gallegos ◽  
Joy Parkinson ◽  
Sinead Duane ◽  
Christine Domegan ◽  
Elena Jansen ◽  
...  
Keyword(s):  
United Kingdom ◽  
Infant Feeding ◽  
Adult Women ◽  
Feeding Mode ◽  
Complex Behaviour ◽  
The United Kingdom ◽  
Country Differences ◽  
Breastfeeding Rates ◽  
The Uk ◽  
Context Models

Abstract Background Breastfeeding is a complex behaviour relying on a combination of individual mother and infant characteristics, health systems, and family, community and professional support. Optimal breastfeeding in high-income countries is particularly low. Despite having similar sociocultural backgrounds, breastfeeding rates between Ireland, the United Kingdom (UK) and Australia vary, thus there is a need to understand whether this is due to individual, sociocultural or policy differences. This research identifies the between-country differences in infant feeding mode and examines if country differences in feeding mode persist once known individual, behavioural and structural factors are considered using socioecological and person-context models. Methods Participants were adult women with at least one infant less than 6 months of age, who completed an online survey (n = 2047) that was distributed by social media in June 2016. Within-country differences in infant feeding mode (‘any breastfeeding’ vs. ‘no breastfeeding’) were examined first before hierarchical multivariable logistic regression was used to determine if country differences in feeding mode persisted after adjusting for known factors associated with breastfeeding. Results In this sample, ‘any breastfeeding’ rates were 89, 71 and 72% in Australia, Ireland and the United Kingdom respectively. Within-country differences were evident in Australia, Ireland and the UK. Four factors showed no association with infant feeding mode in Australia while they did in the other countries (maternal age, income, skin-to-skin contact, support from friends and family). Two factors were unique to Australia: the odds of being in the ‘no breastfeeding’ group increased when the baby was delivered via caesarean and when not enough breastfeeding information was available after birth. One determinant was unique to Ireland: the odds of being in the ‘no breastfeeding’ group increased when respondents indicated they were not religious; in the UK this occurred when respondents were living in a town/village. After adjusting for sets of known factors of infant feeding mode based on socioecological and person-context models, country differences remained in hierarchical regressions: the odds of not breastfeeding were higher in both Ireland (AOR 3.3, 95%CI 1.8,6.1) and the United Kingdom (AOR 2.7, 95%CI 1.5, 4.7) compared to Australia. Conclusions This study indicates that different levels in the socioecological system are related to infant feeding behaviours. An adequate inter-systems level response would consider the interactions within and between behavioural and structural mechanisms which support breastfeeding behaviour. Optimising infant feeding practices will require an integrated web of interventions that go beyond the individual and focus on addressing factors that will influence families within their communities as they move between systems.

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