scholarly journals Protection against lightning on the geomagnetic observatory

2014 ◽  
Vol 4 (1) ◽  
pp. 213-234
Author(s):  
R. Čop ◽  
G. Milev ◽  
D. Deželjin ◽  
J. Kosmač
Keyword(s):  
Electrical Charge ◽  
Secondary Effects ◽  
Geomagnetic Observatory ◽  
Humid Air ◽  
Air Masses ◽  
Thunderstorm Cloud ◽  
Short Time

Abstract. The Sinji Vrh Geomagnetic Observatory was built on the brow of the mountain Gora, above Ajdovščina, and all over Europe one may hardly find an area which is more often struck by lightning than this south-western part of Slovenia. When the humid air masses of a storm front hit the edge of Gora, they rise up more than 1000 m in a very short time, and this causes the additional electrical charge of stormy clouds. The reliability of operations performed in the every building of observatory could be increased by understanding the formation of lightning in the thunderstorm cloud, the application of already proven methods of protection against a strike of lightning and against its secondary effects. To reach this goal the following groups of experts have to co-operate: the experts in the field of protection against lightening phenomenon, the constructors and manufacturers of equipment and the observatory managers.

scholarly journals Protection against lightning at a geomagnetic observatory

2014 ◽  
Vol 3 (2) ◽  
pp. 135-141 ◽  
Author(s):  
R. Čop ◽  
G. Milev ◽  
D. Deželjin ◽  
J. Kosmač
Keyword(s):  
Electrical Charge ◽  
Secondary Effects ◽  
Geomagnetic Observatory ◽  
Southwestern Part ◽  
Humid Air ◽  
Air Masses ◽  
Thunderstorm Cloud ◽  
Short Time

Abstract. The Sinji Vrh Geomagnetic Observatory was built on the brow of Gora, the mountain above Ajdovščina, which is a part of Trnovo plateau, and all over Europe one can hardly find an area which is more often struck by lightning than this southwestern part of Slovenia. When the humid air masses of a storm front hit the edge of Gora, they rise up more than 1000 m in a very short time, and this causes an additional electrical charge of stormy clouds. The reliability of operations performed in every section of the observatory could be increased by understanding the formation of lightning in a thunderstorm cloud and the application of already-proven methods of protection against a stroke of lightning and against its secondary effects. To reach this goal the following groups of experts have to cooperate: experts in the field of protection against lightning, constructors and manufacturers of equipment and observatory managers.

Inflammability and Electrical Studies of Foams Which may Occur at Altitude by De-Aeration of Aviation Turbine Fuels

1959 ◽  
Vol 63 (586) ◽  
pp. 581-588 ◽  
Author(s):  
B. V. Poulston ◽  
A. Thomas
Keyword(s):  
High Altitude ◽  
Sea Level ◽  
Atmospheric Pressure ◽  
Ambient Pressure ◽  
Electrical Charge ◽  
Air Bubbles ◽  
Electrical Studies ◽  
To Come ◽  
Short Time

Air dissolves in aircraft fuels to an extent directly proportional to the ambient pressure, so that when fuel which has been stored at sea-level atmospheric pressure is taken up to a high altitude, there is a tendency for air to come out of solution. In certain circumstances, which are later described in detail, air bubbles can be liberated very violently from fuels in aircraft tanks at high altitude and a thick foam can form on the surface for a short time.The production of fuel foams by degassing has posed a certain problem; foams, being intimate mixtures of air and fuel, may well be inflammable; furthermore, the rising of air bubbles through fuel can result in the accumulation of electrical charge in the foam giving rise to the possibility of a source of ignition.

Dynamic and thermodynamic drivers of Arctic lower tropospheric warm extremes

2020 ◽  
Author(s):  
Lukas Papritz
Keyword(s):  
Storm Track ◽  
Lower Troposphere ◽  
High Arctic ◽  
Heat Fluxes ◽  
The Arctic ◽  
Sensible Heat ◽  
Humid Air ◽  
Secondary Importance ◽  
Air Masses ◽  
Diabatic Processes

<p align="justify">Recent decades have revealed dramatic changes in the high Arctic (> 80°N) related to natural variability and anthropogenic climate change. In particular, episodes of extremely warm temperatures in the lower troposphere and their role for sea ice melting have gained considerable attention. While it has been recognized that injections of warm and humid air masses contribute to wintertime warm anomalies, summertime warm anomalies have also been linked to blocking anticyclones within the high Arctic. Yet, the relative importance of the various thermodynamic and atmospheric dynamical processes that can contribute to the formation of extreme warm anomalies in the high Arctic is poorly understood.</p><p align="justify">In this work, we present a systematic analysis of the processes leading to the formation of winter- and summertime lower tropospheric warm extremes in the high Arctic by means of kinematic backward trajectories based on the ERA-Interim reanalysis. The trajectories enable us to quantify the relative contributions of poleward transport from (potentially) warmer regions, adiabatic warming due to subsidence, and diabatic heating associated with surface sensible heat fluxes and latent heat release. Furthermore, we relate these processes to atmospheric dynamical flow features such as atmospheric blocking and extratropical cyclones.</p><p align="justify">Our analyses reveal that subsidence in blocking anticyclones over the Barents and Kara Seas and diabatic warming by surface sensible heat fluxes are the dominant mechanisms leading to wintertime warm extremes (contributing about 40% each), whereas the transport from southerly latitudes – predominantly accomplished by the injection of warm and humid air masses associated with an intensified and westward displaced storm track in the Nordic Seas - is of secondary importance (20%). Summertime warm anomalies, in contrast, are essentially the result of subsidence in blocking anticyclones (70%) that are located within the high Arctic. Thus, our findings point towards a rich, seasonally varying spectrum of dynamical and thermodynamic processes contributing to Arctic warm extremes that result from a complex interplay between transport induced by dynamical weather systems and diabatic processes. Furthermore, they emphasize the importance of processes within the Arctic for the formation of warm extremes.</p><p align="justify">Papritz, L., 2019: Arctic lower tropospheric warm and cold extremes: horizontal and vertical transport, diabatic processes, and linkage to synoptic circulation features, <em>J. Climate</em>, doi: 10.1175/JCLI-D-19-0638.1</p>

scholarly journals Increasing frequencies of warm and humid air masses over the conterminous United States from 1948 to 2005

2008 ◽  
Vol 35 (10) ◽  
Author(s):  
David B. Knight ◽  
Robert E. Davis ◽  
Scott C. Sheridan ◽  
David M. Hondula ◽  
Luke J. Sitka ◽  
...  
Keyword(s):  
United States ◽  
Humid Air ◽  
Air Masses

scholarly journals Detecting moisture transport pathways to the subtropical North Atlantic free troposphere using paired H<sub>2</sub>O-<i>δ</i>D in situ measurements

2016 ◽  
Vol 16 (7) ◽  
pp. 4251-4269 ◽  
Author(s):  
Yenny González ◽  
Matthias Schneider ◽  
Christoph Dyroff ◽  
Sergio Rodríguez ◽  
Emanuel Christner ◽  
...  
Keyword(s):  
North Atlantic ◽  
In Situ Measurements ◽  
Back Trajectory ◽  
Free Troposphere ◽  
Night Time ◽  
Humid Air ◽  
Transport Pathways ◽  
Air Masses ◽  
Dry Convection

Abstract. We present two years of in situ measurements of water vapour (H2O) and its isotopologue ratio (δD, the standardized ratio between H216O and HD16O), made at two remote mountain sites on Tenerife in the subtropical North Atlantic. We show that the data – if measured during night-time – are well representative for the lower/middle free troposphere. We use the measured H2O-δD pairs, together with dust measurements and back trajectory modelling for analysing the moisture pathways to this region. We can identify four principally different transport pathways. The air mass transport from high altitudes and high latitudes shows two different scenarios. The first scenario brings dry air masses to the stations, as the result of condensation events occurring at low temperatures. The second scenario brings humid air masses to the stations, due to cross-isentropic mixing with lower-level and more humid air during transport since last condensation (LC). The third pathway is transportation from lower latitudes and lower altitudes, whereby we can identify rain re-evaporation as an occasional source of moisture. The fourth pathway is linked to the African continent, where during summer, dry convection processes over the Sahara very effectively inject humidity from the boundary layer to higher altitudes. This so-called Saharan Air Layer (SAL) is then advected westward over the Atlantic and contributes to moisten the free troposphere. We demonstrate that the different pathways leave distinct fingerprints on the measured H2O-δD pairs.

scholarly journals Temporal 10Be Variations in Ice

Radiocarbon ◽  
1983 ◽  
Vol 25 (2) ◽  
pp. 269-278 ◽  
Author(s):  
Juerg Beer ◽  
Michael Andree ◽  
Hans Oeschger ◽  
Bernhard Stauffer ◽  
Richard Balzer ◽  
...  
Keyword(s):  
Residence Time ◽  
Mean Residence Time ◽  
Cosmic Ray ◽  
Early Summer ◽  
Air Masses ◽  
Spallation Reactions ◽  
The Mean ◽  
Short Time ◽  
Snow And Ice

10Be (T1/2 = 1.5·106y) is mainly produced in the atmosphere by cosmic ray spallation reactions on nitrogen and oxygen. About 70 % of the production takes place in the stratosphere. 10Be becomes attached to aerosols within a very short time. If 10Be is produced in the stratosphere some latitudinal mixing occurs. Most of the 10Be is transferred to the troposphere during spring and early summer when, mainly at median latitudes, large stratospheric air masses enter the troposphere. Tropospheric 10Be is deposited rapidly on the earth's surface by precipitation. The mean residence time of 10Be in the atmosphere is ca 1 to 2 years. 10Be removed from the atmosphere by precipitation is either preserved in snow and ice layers, in the topsoil and the biosphere, or it enters the hydrosphere (oceans and lakes), where it is transported to the sediments.

What the replication reformation wrought

2018 ◽  
Vol 41 ◽  
Author(s):  
Barbara A. Spellman ◽  
Daniel Kahneman
Keyword(s):  
Reform Movement ◽  
Short Time

AbstractReplication failures were among the triggers of a reform movement which, in a very short time, has been enormously useful in raising standards and improving methods. As a result, the massive multilab multi-experiment replication projects have served their purpose and will die out. We describe other types of replications – both friendly and adversarial – that should continue to be beneficial.

Periodic Variations in the Coronal Green Line Intensity and their Connection with the White-light Coronal Structures

2000 ◽  
Vol 179 ◽  
pp. 197-200
Author(s):  
Milan Minarovjech ◽  
Milan Rybanský ◽  
Vojtech Rušin
Keyword(s):  
Time Resolution ◽  
White Light ◽  
Short Time Scale ◽  
High Time Resolution ◽  
Green Line ◽  
Periodic Intensity ◽  
Coronal Green Line ◽  
Significant Intensity ◽  
Short Time ◽  
Coronal Structures

AbstractWe present an analysis of short time-scale intensity variations in the coronal green line as obtained with high time resolution observations. The observed data can be divided into two groups. The first one shows periodic intensity variations with a period of 5 min. the second one does not show any significant intensity variations. We studied the relation between regions of coronal intensity oscillations and the shape of white-light coronal structures. We found that the coronal green-line oscillations occur mainly in regions where open white-light coronal structures are located.

Destruction of Actin Filaments by Osmium Tetroxide

1977 ◽  
Vol 35 ◽  
pp. 466-467
Author(s):  
P. Maupin-Szamier ◽  
T. D. Pollard
Keyword(s):  
Actin Filaments ◽  
Time Course ◽  
Osmium Tetroxide ◽  
Rabbit Muscle ◽  
Muscle Actin ◽  
Sodium Phosphate Buffer ◽  
Transmission Electron ◽  
The Difference ◽  
Rates Of Decay ◽  
Short Time

We have studied the destruction of rabbit muscle actin filaments by osmium tetroxide (OSO4) to develop methods which will preserve the structure of actin filaments during preparation for transmission electron microscopy.Negatively stained F-actin, which appears as smooth, gently curved filaments in control samples (Fig. 1a), acquire an angular, distorted profile and break into progressively shorter pieces after exposure to OSO4 (Fig. 1b,c). We followed the time course of the reaction with viscometry since it is a simple, quantitative method to assess filament integrity. The difference in rates of decay in viscosity of polymerized actin solutions after the addition of four concentrations of OSO4 is illustrated in Fig. 2. Viscometry indicated that the rate of actin filament destruction is also dependent upon temperature, buffer type, buffer concentration, and pH, and requires the continued presence of OSO4. The conditions most favorable to filament preservation are fixation in a low concentration of OSO4 for a short time at 0°C in 100mM sodium phosphate buffer, pH 6.0.

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