Potential Source Areas for Atmospheric Lead Reaching Ny-Ålesund from 2010 to 2018

Lead content, enrichment factors, and isotopic composition (208Pb/206Pb and 207Pb/206Pb) measured in atmospheric particulate matter (PM10) samples collected for nine years at Ny-Ålesund (Svalbard islands, Norwegian Arctic) during spring and summer are presented and discussed. The possible source areas (PSA) for particulate inferred from Pb isotope ratio values were compared to cluster analysis of back-trajectories. Results show that anthropogenic Pb dominates over natural crustal Pb, with a recurring higher influence in spring, compared to summer. Crustal Pb accounted for 5–16% of the measured Pb concentration. Anthropogenic Pb was affected by (i) a Central Asian PSA with Pb isotope signature compatible with ores smelted in the Rudny Altai region, at the Russian and Kazakhstan border, which accounted for 85% of the anthropogenic Pb concentration, and (ii) a weaker North American PSA, contributing for the remaining 15%. Central Asian PSA exerted an influence on 71–86% of spring samples, without any significant interannual variation. On the contrary, 59–87% of summer samples were influenced by the North American PSA, with higher contributions during 2015 and 2018. Back-trajectory analysis agreed on the seasonal difference in PSA and highlighted a possible increased influence for North American air masses during summer 2010 and 2018, but not for summer 2015.

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Moisture trajectories during heavy rainfall events using Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model

Journal of Physics Conference Series ◽

10.1088/1742-6596/2070/1/012066 ◽

2021 ◽

Vol 2070 (1) ◽

pp. 012066

Author(s):

S Aryalakshmi ◽

Dhanya Madhu

Keyword(s):

Single Particle ◽

Moisture Transport ◽

Heavy Rainfall ◽

Back Trajectory ◽

Hysplit Model ◽

Monsoon Period ◽

Back Trajectories ◽

North East ◽

The North ◽

South West Monsoon

Abstract Heavy rainfall inducing other catastrophic events are frequently experienced globally. Understanding the mechanisms of moisture transport during such events will help in furthering our knowledge about such systems. In the current study, estimation of most likely moisture trajectoriesis performed using back trajectory analyses. Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model available from National Oceanic and Atmospheric Administration’s (NOAA) Air Resources Laboratory (ARL) is used for the purpose. A preliminary analysis is conducted by calculating the frequencies of back trajectories from two locations in Kerala for three heavy rainfall cases. The analysis indicates that both the locations have similar pattern of moisture trajectories during the cases occurring in south west monsoon and pre monsoon periods. However, a change in the behaviour of the trajectories for the two locations is observed for the case during the north east monsoon period. Since this study involved only individual cases, robust conclusions cannot be made based on this for the dynamics of moisture transport for these locations. More detailed analysis will follow this preliminary study in future for the purpose.

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Systematics and taxonomic diversity of squamates from the Upper Cretaceous Djadochta Formation, Bayan Mandahu, Gobi Desert, People's Republic of China

Canadian Journal of Earth Sciences ◽

10.1139/e96-043 ◽

1996 ◽

Vol 33 (4) ◽

pp. 578-598 ◽

Cited By ~ 24

Author(s):

Keqin Gao ◽

Lianhai Hou

Keyword(s):

North American ◽

Upper Cretaceous ◽

Low Frequency ◽

Taxonomic Diversity ◽

Gobi Desert ◽

Republic Of China ◽

Terrestrial Vertebrates ◽

The North ◽

Central Asian ◽

Warm Temperate

Squamate fossils collected for the Sino-Canadian dinosaur expeditions (1986–1990) include some 70 specimens from the Upper Cretaceous (Campanian) Djadochta Formation, exposed at the vicinity of Bayan Mandahu, Inner Mongolia, China. Well-preserved skulls, jaws, postcranial skeletons, and even osteodermal armor document a fossil assemblage composed of at least 18 genera in 8 families. Besides showing considerable taxonomic diversity, several families recorded in the assemblage are of importance in understanding the geologic and biogeographic distribution of the relevant groups, and the paleoenvironment in which these lizards lived. Comparison of the Gobi lizard assemblage with North American and Central Asian assemblages is briefly discussed. Taxonomic differences in the assemblage from that of the Upper Cretaceous in the North American Western Interior reflect endemism and suggest a low frequency of interchange of small terrestrial vertebrates between the two regions during Campanian time. The taphonomic setting of the squamate fossils indicates quick burial in arid to semiarid environments in the Gobi Desert, differing importantly from the Western Interior of North America, where the accumulation of disarticulated jaw fragments reflects postmortem decomposition and fluvial transportation under subtropical to warm temperate conditions.

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