Source Regions

2021 ◽  
pp. 65-140
Author(s):  
Eugene G. Morozov ◽  
Roman Y. Tarakanov ◽  
Dmitry I. Frey
Keyword(s):  
Source Regions

Mobility Source Regions in West Bengal

2017 ◽  
Vol 31 (1) ◽  
pp. 35
Author(s):  
Manoj Debnath ◽  
D. K. Nayak
Keyword(s):  
West Bengal ◽  
Source Regions

scholarly journals Variability of springtime transpacific pollution transport during 2000–2006: the INTEX-B mission in the context of previous years

2010 ◽  
Vol 10 (3) ◽  
pp. 1345-1359 ◽  
Author(s):  
G. G. Pfister ◽  
L. K. Emmons ◽  
D. P. Edwards ◽  
A. Arellano ◽  
T. Campos ◽  
...  
Keyword(s):  
Transport Model ◽  
Pollution Transport ◽  
Chemistry Transport Model ◽  
Pollution Levels ◽  
Annual Variability ◽  
Source Regions ◽  
Time Period ◽  
The Pacific ◽  
The Us ◽  
Transport Experiment

Abstract. We analyze the transport of pollution across the Pacific during the NASA INTEX-B (Intercontinental Chemical Transport Experiment Part B) campaign in spring 2006 and examine how this year compares to the time period for 2000 through 2006. In addition to aircraft measurements of carbon monoxide (CO) collected during INTEX-B, we include in this study multi-year satellite retrievals of CO from the Measurements of Pollution in the Troposphere (MOPITT) instrument and simulations from the chemistry transport model MOZART-4. Model tracers are used to examine the contributions of different source regions and source types to pollution levels over the Pacific. Additional modeling studies are performed to separate the impacts of inter-annual variability in meteorology and dynamics from changes in source strength. Interannual variability in the tropospheric CO burden over the Pacific and the US as estimated from the MOPITT data range up to 7% and a somewhat smaller estimate (5%) is derived from the model. When keeping the emissions in the model constant between years, the year-to-year changes are reduced (2%), but show that in addition to changes in emissions, variable meteorological conditions also impact transpacific pollution transport. We estimate that about 1/3 of the variability in the tropospheric CO loading over the contiguous US is explained by changes in emissions and about 2/3 by changes in meteorology and transport. Biomass burning sources are found to be a larger driver for inter-annual variability in the CO loading compared to fossil and biofuel sources or photochemical CO production even though their absolute contributions are smaller. Source contribution analysis shows that the aircraft sampling during INTEX-B was fairly representative of the larger scale region, but with a slight bias towards higher influence from Asian contributions.

scholarly journals Enhanced Chlorinated very Short-Lived Substances in South East Asia: Potential Source Regions and Source Types

2020 ◽  
Vol 616 ◽  
pp. 012011
Author(s):  
Norfazrin Mohd Hanif ◽  
Claire E. Reeves ◽  
David E. Oram ◽  
Matthew J. Ashfold ◽  
Marios Panagi ◽  
...  
Keyword(s):  
East Asia ◽  
South East Asia ◽  
Source Regions ◽  
Potential Source

Investigation of potential source regions of atmospheric Black Carbon in the data deficit region of the western Himalayas and its foothills

2019 ◽  
Vol 10 (6) ◽  
pp. 1832-1842 ◽  
Author(s):  
Ashish Soni ◽  
Stefano Decesari ◽  
Vijay Shridhar ◽  
Vignesh Prabhu ◽  
Pooja Panwar ◽  
...  
Keyword(s):  
Black Carbon ◽  
Western Himalayas ◽  
Source Regions ◽  
Potential Source

scholarly journals Out of the Neotropics: Late Cretaceous colonization of Australasia by American arthropods

2012 ◽  
Vol 279 (1742) ◽  
pp. 3501-3509 ◽  
Author(s):  
Prashant P. Sharma ◽  
Gonzalo Giribet
Keyword(s):  
Late Cretaceous ◽  
Divergence Time ◽  
Disjunct Distribution ◽  
Continental Margins ◽  
Divergence Time Estimates ◽  
Evolutionary Origins ◽  
Source Regions ◽  
Time Estimates ◽  
Fiji Islands ◽  
The Pacific

The origins of tropical southwest Pacific diversity are traditionally attributed to southeast Asia or Australia. Oceanic and fragment islands are typically colonized by lineages from adjacent continental margins, resulting in attrition of diversity with distance from the mainland. Here, we show that an exceptional tropical family of harvestmen with a trans-Pacific disjunct distribution has its origin in the Neotropics. We found in a multi-locus phylogenetic analysis that the opilionid family Zalmoxidae, which is distributed in tropical forests on both sides of the Pacific, is a monophyletic entity with basal lineages endemic to Amazonia and Mesoamerica. Indo-Pacific Zalmoxidae constitute a nested clade, indicating a single colonization event. Lineages endemic to putative source regions, including Australia and New Guinea, constitute derived groups. Divergence time estimates and probabilistic ancestral area reconstructions support a Neotropical origin of the group, and a Late Cretaceous ( ca 82 Ma) colonization of Australasia out of the Fiji Islands and/or Borneo, which are consistent with a transoceanic dispersal event. Our results suggest that the endemic diversity within traditionally defined zoogeographic boundaries might have more complex evolutionary origins than previously envisioned.

scholarly journals Pan-Arctic aerosol number size distributions: seasonality and transport patterns

2017 ◽  
Vol 17 (13) ◽  
pp. 8101-8128 ◽  
Author(s):  
Eyal Freud ◽  
Radovan Krejci ◽  
Peter Tunved ◽  
Richard Leaitch ◽  
Quynh T. Nguyen ◽  
...  
Keyword(s):  
Arctic Ocean ◽  
Regional Scale ◽  
Arctic Region ◽  
The Arctic ◽  
Research Station ◽  
Size Distributions ◽  
Back Trajectories ◽  
Accumulation Mode ◽  
Source Regions ◽  
The Arctic Ocean

Abstract. The Arctic environment has an amplified response to global climatic change. It is sensitive to human activities that mostly take place elsewhere. For this study, a multi-year set of observed aerosol number size distributions in the diameter range of 10 to 500 nm from five sites around the Arctic Ocean (Alert, Villum Research Station – Station Nord, Zeppelin, Tiksi and Barrow) was assembled and analysed.A cluster analysis of the aerosol number size distributions revealed four distinct distributions. Together with Lagrangian air parcel back-trajectories, they were used to link the observed aerosol number size distributions with a variety of transport regimes. This analysis yields insight into aerosol dynamics, transport and removal processes, on both an intra- and an inter-monthly scale. For instance, the relative occurrence of aerosol number size distributions that indicate new particle formation (NPF) event is near zero during the dark months, increases gradually to  ∼ 40 % from spring to summer, and then collapses in autumn. Also, the likelihood of Arctic haze aerosols is minimal in summer and peaks in April at all sites.The residence time of accumulation-mode particles in the Arctic troposphere is typically long enough to allow tracking them back to their source regions. Air flow that passes at low altitude over central Siberia and western Russia is associated with relatively high concentrations of accumulation-mode particles (Nacc) at all five sites – often above 150 cm−3. There are also indications of air descending into the Arctic boundary layer after transport from lower latitudes.The analysis of the back-trajectories together with the meteorological fields along them indicates that the main driver of the Arctic annual cycle of Nacc, on the larger scale, is when atmospheric transport covers the source regions for these particles in the 10-day period preceding the observations in the Arctic. The scavenging of these particles by precipitation is shown to be important on a regional scale and it is most active in summer. Cloud processing is an additional factor that enhances the Nacc annual cycle.There are some consistent differences between the sites that are beyond the year-to-year variability. They are the result of differences in the proximity to the aerosol source regions and to the Arctic Ocean sea-ice edge, as well as in the exposure to free-tropospheric air and in precipitation patterns – to mention a few. Hence, for most purposes, aerosol observations from a single Arctic site cannot represent the entire Arctic region. Therefore, the results presented here are a powerful observational benchmark for evaluation of detailed climate and air chemistry modelling studies of aerosols throughout the vast Arctic region.

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