The Role of Boundary-Layer Convergence Zones and Horizontal Rolls in the Initiation of Thunderstorms: A Case Study

1992 ◽  
Vol 120 (9) ◽  
pp. 1785-1815 ◽  
Author(s):  
James W. Wilson ◽  
G. Brant Foote ◽  
N. Andrew Cṙook ◽  
James C. Fankhauser ◽  
Charles G. Wade ◽  
...  
2021 ◽  
Author(s):  
Shaddy Ahmed ◽  
Jennie L Thomas ◽  
Kathleen Tuite ◽  
Jochen Stutz ◽  
Frank Flocke ◽  
...  

2021 ◽  
Author(s):  
Saewung Kim ◽  
Roger Seco ◽  
Dasa Gu ◽  
Dianne Sanchez ◽  
Daun Jeong ◽  
...  

This study presents vertical distributions of trace gases and OH reactivity in Seoul Metropolitan Area. The comparison between a suburban ground site and an airborne platform illustrates a rapid photo oxidation in the very bottom of the boundary layer.


2014 ◽  
Vol 21 (2) ◽  
pp. 489-501
Author(s):  
I. M. Mazzitelli ◽  
M. Cassol ◽  
M. M. Miglietta ◽  
U. Rizza ◽  
A. M. Sempreviva ◽  
...  

Abstract. The diurnal evolution of a cloud free, marine boundary layer is studied by means of experimental measurements and numerical simulations. Experimental data belong to an investigation of the mixing height over inner Danish waters. The mixed-layer height measured over the sea is generally nearly constant, and does not exhibit the diurnal cycle characteristic of boundary layers over land. A case study, during summer, showing an anomalous development of the mixed layer under unstable and nearly neutral atmospheric conditions, is selected in the campaign. Subsidence is identified as the main physical mechanism causing the sudden decrease in the mixing layer height. This is quantified by comparing radiosounding profiles with data from numerical simulations of a mesoscale model, and a large-eddy simulation model. Subsidence not only affects the mixing layer height, but also the turbulent fluctuations within it. By analyzing wind and scalar spectra, the role of subsidence is further investigated and a more complete interpretation of the experimental results emerges.


Author(s):  
Fu Dong ◽  
Ling Zhang ◽  
Weidong Chen ◽  
Dengxuan Li ◽  
Jia Wang ◽  
...  

1987 ◽  
Author(s):  
William A. Worrall ◽  
Ann W. Stockman

TAPPI Journal ◽  
2009 ◽  
Vol 8 (1) ◽  
pp. 20-26 ◽  
Author(s):  
PEEYUSH TRIPATHI ◽  
MARGARET JOYCE ◽  
PAUL D. FLEMING ◽  
MASAHIRO SUGIHARA

Using an experimental design approach, researchers altered process parameters and material prop-erties to stabilize the curtain of a pilot curtain coater at high speeds. Part I of this paper identifies the four significant variables that influence curtain stability. The boundary layer air removal system was critical to the stability of the curtain and base sheet roughness was found to be very important. A shear thinning coating rheology and higher curtain heights improved the curtain stability at high speeds. The sizing of the base sheet affected coverage and cur-tain stability because of its effect on base sheet wettability. The role of surfactant was inconclusive. Part II of this paper will report on further optimization of curtain stability with these four variables using a D-optimal partial-facto-rial design.


2019 ◽  
Vol 3 (1) ◽  
pp. 1-9
Author(s):  
Robert M. Anderson ◽  
Amy M. Lambert

The island marble butterfly (Euchloe ausonides insulanus), thought to be extinct throughout the 20th century until re-discovered on a single remote island in Puget Sound in 1998, has become the focus of a concerted protection effort to prevent its extinction. However, efforts to “restore” island marble habitat conflict with efforts to “restore” the prairie ecosystem where it lives, because of the butterfly’s use of a non-native “weedy” host plant. Through a case study of the island marble project, we examine the practice of ecological restoration as the enactment of particular norms that define which species are understood to belong in the place being restored. We contextualize this case study within ongoing debates over the value of “native” species, indicative of deep-seated uncertainties and anxieties about the role of human intervention to alter or manage landscapes and ecosystems, in the time commonly described as the “Anthropocene.” We interpret the question of “what plants and animals belong in a particular place?” as not a question of scientific truth, but a value-laden construct of environmental management in practice, and we argue for deeper reflexivity on the part of environmental scientists and managers about the social values that inform ecological restoration.


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