scholarly journals Non-volant modes of migration in terrestrial arthropods

2014 ◽  
Vol 2 (1) ◽  
Author(s):  
Don R. Reynolds ◽  
Andrew M. Reynolds ◽  
Jason W. Chapman
Keyword(s):  
Atmospheric Transport ◽  
Transport Processes ◽  
Biological Processes ◽  
Factors Affecting ◽  
Terrestrial Arthropods ◽  
Taxonomic Range ◽  
Migratory Movements ◽  
Dispersal Kernels ◽  
Typical Mode ◽  
Behavioural Adaptations

AbstractAnimal migration is often defined in terms appropriate only to the ‘to-and-fro’ movements of large, charismatic (and often vertebrate) species. However, like other important biological processes, the definition should apply over as broad a taxonomic range as possible in order to be intellectually satisfying. Here we illustrate the process of migration in insects and other terrestrial arthropods (e.g. arachnids, myriapods, and non-insect hexapods) but provide a different perspective by excluding the ‘typical’ mode of migration in insects, i.e. flapping flight. Instead, we review non-volant migratory movements, including: aerial migration by wingless species, pedestrian and waterborne migration, and phoresy. This reveals some fascinating and sometimes bizarre morphological and behavioural adaptations to facilitate movement. We also outline some innovative modelling approaches exploring the interactions between atmospheric transport processes and biological factors affecting the ‘dispersal kernels’ of wingless arthropods

scholarly journals Evaluation of the atmospheric transport in a GCM using radon measurements: sensitivity to cumulus convection parameterization

2008 ◽  
Vol 8 (10) ◽  
pp. 2811-2832 ◽  
Author(s):  
K. Zhang ◽  
H. Wan ◽  
M. Zhang ◽  
B. Wang
Keyword(s):  
Vertical Distribution ◽  
Radon Concentration ◽  
Large Scale ◽  
Atmospheric Transport ◽  
Surface Concentration ◽  
Transport Processes ◽  
Cumulus Convection ◽  
Models Comparison ◽  
Convection Schemes ◽  
Convection Parameterization

Abstract. The radioactive species radon (222Rn) has long been used as a test tracer for the numerical simulation of large scale transport processes. In this study, radon transport experiments are carried out using an atmospheric GCM with a finite-difference dynamical core, the van Leer type FFSL advection algorithm, and two state-of-the-art cumulus convection parameterization schemes. Measurements of surface concentration and vertical distribution of radon collected from the literature are used as references in model evaluation. The simulated radon concentrations using both convection schemes turn out to be consistent with earlier studies with many other models. Comparison with measurements indicates that at the locations where significant seasonal variations are observed in reality, the model can reproduce both the monthly mean surface radon concentration and the annual cycle quite well. At those sites where the seasonal variation is not large, the model is able to give a correct magnitude of the annual mean. In East Asia, where radon simulations are rarely reported in the literature, detailed analysis shows that our results compare reasonably well with the observations. The most evident changes caused by the use of a different convection scheme are found in the vertical distribution of the tracer. The scheme associated with weaker upward transport gives higher radon concentration up to about 6 km above the surface, and lower values in higher altitudes. In the lower part of the atmosphere results from this scheme does not agree as well with the measurements as the other scheme. Differences from 6 km to the model top are even larger, although we are not yet able to tell which simulation is better due to the lack of observations at such high altitudes.

Preliminary results of the first assessment of 20 years of dust activity in the Patagonia desert (South America) with aerosol products from the MODIS sensors

2021 ◽  
Author(s):  
Santiago Gassó ◽  
Pawan Gupta ◽  
Paul Ginoux ◽  
Robert Levy
Keyword(s):  
Time Series ◽  
South America ◽  
Volcanic Eruptions ◽  
Transport Processes ◽  
Dust Storms ◽  
Biological Processes ◽  
Aerosol Transport ◽  
Deep Blue ◽  
Fire Activity ◽  
Analysis Of Time Series

<p>Aerosol transport processes in the Southern Hemisphere (SH) have been the center of renewed attention in the last two decades because of a number of major geophysical events such as volcanic eruptions (Chile and Argentina), biomass burning (Australia and Chile) and dust storms (Australia and Argentina).<br><br>While volcanic and fire activity in the SH have been the focus of several studies, there is a dearth of satellite assessments of dust activity. The lack of such analysis impairs the understanding of biological processes in the Southern Ocean and of the provenance of dust found in snow at the surface of East Antarctica.<br><br>This presentation will show an analysis of time series of Aerosol Optical Depths over the Patagonia desert in South America. Data from two aerosol algorithms (Dark Target and Deep Blue) will be jointly analyzed to establish a timeline of dust activity in the region. Also, dust proxies from both algorithms will be compared with ground-based observations of visibility at different airports in the area. Once an understanding of frequency and time evolution of the dust activity is achieved, first estimations of ocean-going dust fluxes will be derived.</p>

scholarly journals Transport of short-lived halocarbons to the stratosphere over the Pacific Ocean

2020 ◽  
Vol 20 (2) ◽  
pp. 1163-1181
Author(s):  
Michal T. Filus ◽  
Elliot L. Atlas ◽  
Maria A. Navarro ◽  
Elena Meneguz ◽  
David Thomson ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Lower Stratosphere ◽  
Atmospheric Transport ◽  
Convective Transport ◽  
Transport Processes ◽  
Lagrangian Model ◽  
Convection Scheme ◽  
Model Calculations ◽  
Upper Troposphere ◽  
Tropical Troposphere

Abstract. The effectiveness of transport of short-lived halocarbons to the upper troposphere and lower stratosphere remains an important uncertainty in quantifying the supply of ozone-depleting substances to the stratosphere. In early 2014, a major field campaign in Guam in the western Pacific, involving UK and US research aircraft, sampled the tropical troposphere and lower stratosphere. The resulting measurements of CH3I, CHBr3 and CH2Br2 are compared here with calculations from a Lagrangian model. This methodology benefits from an updated convection scheme that improves simulation of the effect of deep convective motions on particle distribution within the tropical troposphere. We find that the observed CH3I, CHBr3 and CH2Br2 mixing ratios in the tropical tropopause layer (TTL) are consistent with those in the boundary layer when the new convection scheme is used to account for convective transport. More specifically, comparisons between modelled estimates and observations of short-lived CH3I indicate that the updated convection scheme is realistic up to the lower TTL but is less good at reproducing the small number of extreme convective events in the upper TTL. This study consolidates our understanding of the transport of short-lived halocarbons to the upper troposphere and lower stratosphere by using improved model calculations to confirm consistency between observations in the boundary layer, observations in the TTL and atmospheric transport processes. Our results support recent estimates of the contribution of short-lived bromocarbons to the stratospheric bromine budget.

scholarly journals Aerobiology: Experimental Considerations, Observations, and Future Tools

2017 ◽  
Vol 83 (17) ◽  
Author(s):  
Allen E. Haddrell ◽  
Richard J. Thomas
Keyword(s):  
Atmospheric Chemistry ◽  
Atmospheric Transport ◽  
Method Comparison ◽  
Careful Consideration ◽  
Biological Processes ◽  
Single Droplet ◽  
Aerosol Generation ◽  
Research Fields ◽  
Molecular Microbiology ◽  
Modeling Techniques

ABSTRACT Understanding airborne survival and decay of microorganisms is important for a range of public health and biodefense applications, including epidemiological and risk analysis modeling. Techniques for experimental aerosol generation, retention in the aerosol phase, and sampling require careful consideration and understanding so that they are representative of the conditions the bioaerosol would experience in the environment. This review explores the current understanding of atmospheric transport in relation to advances and limitations of aerosol generation, maintenance in the aerosol phase, and sampling techniques. Potential tools for the future are examined at the interface between atmospheric chemistry, aerosol physics, and molecular microbiology where the heterogeneity and variability of aerosols can be explored at the single-droplet and single-microorganism levels within a bioaerosol. The review highlights the importance of method comparison and validation in bioaerosol research and the benefits that the application of novel techniques could bring to increasing the understanding of aerobiological phenomena in diverse research fields, particularly during the progression of atmospheric transport, where complex interdependent physicochemical and biological processes occur within bioaerosol particles.

scholarly journals Factors affecting the atmospheric occurrence and deposition of polychlorinated biphenyls in the Southern Ocean

2013 ◽  
Vol 13 (23) ◽  
pp. 12029-12041 ◽  
Author(s):  
C. J. Galbán-Malagón ◽  
S. Del Vento ◽  
A. Cabrerizo ◽  
J. Dachs
Keyword(s):  
Polychlorinated Biphenyls ◽  
Southern Ocean ◽  
Gas Phase ◽  
Long Range ◽  
Atmospheric Transport ◽  
Austral Summer ◽  
Deposition Flux ◽  
Atmospheric Concentration ◽  
Factors Affecting ◽  
Antarctic Soils

Abstract. Persistent organic pollutants, such as polychlorinated biphenyls, reach the Southern Ocean atmosphere through long-range atmospheric transport. In this study we report the largest dataset available for the atmospheric occurrence of PCBs in the Southern Ocean surrounding the Antarctic Peninsula from samples obtained during three cruises in 2005, 2008 and 2009. The gas phase concentrations of total PCBs (Σ25PCBs) ranged from 1 to 70 pg m−3, while the aerosol phase concentrations were significantly lower (0.04 to 0.4 pg m−3). The aerosol phase is enriched in the more hydrophobic congeners consistent with the model predictions of gas-particle partitioning. There is a net air-to-water diffusive flux of PCBs to the Southern Ocean, up to 100 times higher than the dry deposition flux of aerosol-bound PCBs. The air-water disequilibrium is higher for the more hydrophobic congeners consistent with the role of the biological pump removing PCBs from the water column by settling of PCBs bound to organic matter. The atmospheric half-lives of PCB 52 and 180 are of 3.8 and 1 days, respectively, as calculated from the measured atmospheric concentration and depositional fluxes. The volatilization of PCBs from Antarctic soils during the austral summer drives higher gas phase concentrations in the atmosphere over Antarctica during the warmer periods. This temperature dependence is not observed for PCBs over the adjacent Southern Ocean, probably due to the importance of long-range atmospheric transport and atmospheric deposition modulating the atmospheric occurrence of PCBs.

scholarly journals Evaluation of size segregation of elemental carbon emission in Europe: influence on atmospheric long-range transportation

2015 ◽  
Vol 15 (21) ◽  
pp. 31053-31087 ◽  
Author(s):  
Y. Chen ◽  
Y. F. Cheng ◽  
S. Nordmann ◽  
W. Birmili ◽  
H. A. C. Denier van der Gon ◽  
...  
Keyword(s):  
Long Range ◽  
Elemental Carbon ◽  
Atmospheric Transport ◽  
Transport Processes ◽  
Point Sources ◽  
Size Segregation ◽  
Wind Pattern ◽  
Coarse Mode ◽  
Nearby Point ◽  
Emission Fraction

Abstract. Elemental Carbon (EC) has significant impact on human health and climate change. In order to evaluate the size segregation of EC emission and investigation of its influence on atmospheric transport processes in Europe, we used the fully coupled online Weather Research and Forecasting/Chemistry model (WRF-Chem) at a resolution of 2 km focusing on a region in Germany, in conjunction with a high-resolution EC emission inventory. The ground meteorology conditions, vertical structure and wind pattern were well reproduced by the model. The simulations of particle number/mass size distributions were evaluated by observations taken at the central European background site Melpitz. The fine mode aerosol was reasonably well simulated, but the coarse mode was substantially overestimated by the model. We found that it was mainly due to the nearby point source plume emitting a high amount of EC in the coarse mode. The comparisons between simulated EC and Multi-angle Absorption Photometers (MAAP) measurements at Melpitz, Leipzig-TROPOS and Bösel indicated that coarse mode EC (ECc) emission in the nearby point sources might be overestimated by a factor of 2–10. The emission fraction of EC in coarse mode was overestimated by about 10–30 % for Russian and 5–10 % for Eastern Europe (e.g.: Poland and Belarus), respectively. This overestimation in ECc emission fraction makes EC particles having less opportunity to accumulate in the atmosphere and participate to the long range transport, due to the shorter lifetime of coarse mode aerosol. The deposition concept model showed that the transported EC mass from Warsaw and Moskva to Melpitz may be reduced by 25–35 and 25–55 % respectively, due to the overestimation of ECc emission fraction. This may partly explain the underestimation of EC concentrations for Germany under eastern wind pattern in some other modelling research.

scholarly journals Measurements of NO, NO<sub>y</sub>, N<sub>2</sub>O, and O<sub>3</sub> during SPURT: implications for transport and chemistry in the lowermost stratosphere

2005 ◽  
Vol 5 (5) ◽  
pp. 8649-8688 ◽  
Author(s):  
M. I. Hegglin ◽  
D. Brunner ◽  
Th. Peter ◽  
P. Hoor ◽  
H. Fischer ◽  
...  
Keyword(s):  
Atmospheric Transport ◽  
Potential Temperature ◽  
Transport Processes ◽  
Ozone Production ◽  
Data Set ◽  
Latitude Range ◽  
Mixing Ratios ◽  
Tropical Tropopause ◽  
Tropopause Region ◽  
Extratropical Tropopause

Abstract. We present measurements of NO, NOy, O3, and N2O within the lowermost stratosphere (LMS) over Europe obtained during the SPURT project. The measurements cover each of the four seasons during two years between November 2001 and July 2003, and probe the entire altitude and latitude range of the LMS: from 5° N to 85° N equivalent latitude, and from 290 to 375 K potential temperature. The measurements represent a comprehensive data set of these tracers and reveal atmospheric transport processes that influence tracer distributions in the LMS. Mean mixing ratios of stratospheric tracers in equivalent latitude-potential temperature coordinates show a clear seasonal cycle related to the Brewer-Dobson circulation with highest values in spring and lowest values in autumn. Vertical profiles show strong gradients at the extratropical tropopause suggesting that vertical (cross-isentropic) mixing is reduced above the tropopause. Mixing along isentropes is also strongly reduced since pronounced meridional gradients are found on potential temperature surfaces in the LMS. Concurrent large gradients in PV in the vertical and in the meridional direction horizontally suggest the presence of a transport and mixing barrier. Well above the tropopause distinguished seasonal cycles were found in the correlation slopes ΔO3/ΔN2O and ΔNOy/ΔN2O. Smallest slopes found during spring indicate chemically aged stratospheric air originating from high altitudes and latitudes. The slopes are larger in summer and autumn suggesting that a substantial fraction of air takes a 'short-cut' from the tropical tropopause region into the extratropical LMS. The comparison of measured NO with critical NO values at which net ozone production changes from negative to positive implies a net ozone production up to 20 K above the local tropopause in winter, increasing during spring and summer to up to 50 K in autumn. Above this height NO values favor ozone destruction.

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