scholarly journals Study of strong tornadoes in Central Europe: Various aspects of Forecasting and Nowcasting

2021 ◽  
Author(s):  
Kathrin Wapler ◽  
Marcus Beyer
Keyword(s):  
Situational Awareness ◽  
Great Majority ◽  
Short Wave ◽  
The Other ◽  
Typical Situation ◽  
Wave Trough ◽  
Area Of Interest ◽  
Storm Evolution ◽  
Upper Level ◽  
Tornadic Storms

<p>Tornados pose a significant threat to life, property, and economy. Thus, an analysis of tornadoes is of high relevance. An understanding of historical events, e.g. regarding the characteristics of tornadic storms compared to multi-year storm statistics, may help to improve the situational awareness of future tornado events.</p><p>In this study, tornadic storms with a tornado intensity of F2 or stronger on the Fujita scale that occurred in recent years (2016 – 2020) in Germany were analyzed in detail. The four F3 tornadoes (Bützow, Affing, Bonndorf and Roetgen) and sixteen F2 tornadoes, which developed on 17 different days occurred in various parts of Germany. Most of the analysed tornadoes occurred from May to early September. The other three cases are typical winter cases that differ significantly from the summer cases in some aspects that are discussed where applicable. One case which happened in the third decade of September has characteristics form both, summer and winter, and is thus the only hybrid case. The great majority of all cases occurred during the second half of the day, most of them between 12 and 18 UTC. The most active hour was 16 to 17 UTC.</p><p>Regarding forecasting, similarities and differences of the prevailing synoptic and mesoscale conditions are assessed in addition to the convective environment of the events. Furthermore, the type of convection is analysed. The goal is to anticipate typical characteristics that enhance the threat of a potentially dangerous tornado situation. Using these findings may then help to strengthen the awareness of the forecaster. Two situations in mid- and upper-level flow are typical for the occurrence of strong tornadoes. On the majority of the analysed tornadic days, the event happened on the forward flank of a long wave trough that was slowly propagating eastward. The other typical situation is a vivid short wave trough passing rather fast over the area of interest from West to East.</p><p>Regarding nowcasting, a multi-source approach was applied to best analyse the events. For this purpose, radar reflectivity and rotation data were combined with lightning detection in order to analyse the tornadic storms with respect to storm mode and storm evolution as well as lightning and rotation characteristics. In many cases, radar radial wind data showed a persistent rotation track. The automatically detected mesocyclones had a vertical depth between 2.5 and 11 km at the time of the tornado, the diameter was above 8 km. The base of the rotation was low compared to multi-year statistics of all mesocyclonic storms. The lighting activity of the tornadic storms was high. In many cases, a lightning jump occurred between 5 and 120 minutes before the event.</p>

scholarly journals The Integral Role of a Diabatic Rossby Vortex in a Heavy Snowfall Event

2008 ◽  
Vol 136 (6) ◽  
pp. 1878-1897 ◽  
Author(s):  
Richard W. Moore ◽  
Michael T. Montgomery ◽  
Huw C. Davies
Keyword(s):  
Mesoscale Model ◽  
Heavy Precipitation ◽  
Short Wave ◽  
Low Level ◽  
Wave Trough ◽  
Surface Cyclone ◽  
Integral Role ◽  
Surface Disturbance ◽  
Upper Level ◽  
Inversion Techniques

Abstract On 24–25 February 2005, a significant East Coast cyclone deposited from 4 to nearly 12 in. (∼10–30 cm) of snow on parts of the northeastern United States. The heaviest snowfall and most rapid deepening of the cyclone coincided with the favorable positioning of an upper-level, short-wave trough immediately upstream of a preexisting surface cyclone. The surface cyclone in question formed approximately 15 h before the heaviest snowfall along a coastal front in a region of frontogenesis and heavy precipitation. The incipient surface cyclone subsequently intensified as it moved to the northeast, consistently generating the strongest convection to the east-northeast of the low-level circulation center. The use of potential vorticity (PV) inversion techniques and a suite of mesoscale model simulations illustrates that the early intensification of the incipient surface cyclone was primarily driven by diabatic effects and was not critically dependent on the upper-level wave. These facts, taken in conjunction with the observed structure, energetics, and Lagrangian evolution of the incipient surface disturbance, identify it as a diabatic Rossby vortex (DRV). The antecedent surface vorticity spinup associated with the DRV phase of development is found to be integral to the subsequent rapid growth. The qualitative similarity with a number of observed cases of explosive cyclogenesis leaves open the possibility that a DRV-like feature comprises the preexisting positive low-level PV anomaly in a number of cyclogenetic events that exhibit a two-stage evolution.

scholarly journals Exploiting the Binocular Head in Polarized Light Microscopy

1994 ◽  
Vol 2 (4) ◽  
pp. 16-16
Author(s):  
Walter C. McCrone
Keyword(s):  
Light Microscopy ◽  
Polarized Light ◽  
Polarized Light Microscopy ◽  
The Other ◽  
Monocular Viewing ◽  
Area Of Interest

Having been brought up on monocular microscopes I find the omnipresent binocular systems a luxury. To support this viewpoint I'd like to suggest some benefits you may not have considered.Because I'm used to monocular viewing I sometimes use two different oculars, say 10X and 25X, in order to scan quickly to find an area of interest and then to examine the detail with higher magnification. Occasionally I use both oculars simultaneously and “concentrate” on either image to the exclusion of the other. A better way is to set the interocular distance at the extreme setting most different from your own interocular distance. By moving your head about a centimeter either way you can use either ocular.

scholarly journals Change detection and building spatial geodatabase for Iraqi marshes

2018 ◽  
Vol 162 ◽  
pp. 03021
Author(s):  
Oday Jasim ◽  
Noor Hamed ◽  
Tamarra Abdulgabar
Keyword(s):  
Data Collection ◽  
Spatial Data ◽  
Satellite Images ◽  
The Other ◽  
Image Mosaic ◽  
Economic Potential ◽  
Second Stage ◽  
Area Of Interest ◽  
Natural Factors ◽  
Three Stages

The Iraqi Marshlands has natural and economic potential through its environment rich in various forms of lives. This region has suffered numerous setbacks due to human and natural factors, especially in the last two decades of the last century, which led to significant environmental degradation. The purpose of this paper is to prepare spatial data for the area of the marshes in Iraq as a base (Hour-al Hoveizah and central marshes and Hammar). Also, the other aim is to produce a digital geodatabase for the marshes for the years 1973, 1986, 1999, 2006 and 2016 by using ArcGIS. The process of building geodatabase has been through done in three stages: the first stage is including data collection. The second stage will be by merging the satellite images covering the Iraqi marshes and add to images in order to get the image mosaic process. Also, a georeferencing of satellite images is to be done with all the traditional maps of the same area of the marsh. Finally, complete the full geodatabase for the area of interest by using ArcGIS as the in Cartography Design. The results of this research would be a geodatabase for the Iraqi marshes.

Roma and Constantinopolis in Late-Antique Art From 312 to 365

1947 ◽  
Vol 37 (1-2) ◽  
pp. 135-144 ◽  
Author(s):  
J. M. C. Toynbee
Keyword(s):  
Religious Belief ◽  
Great Majority ◽  
Complex Problem ◽  
The Other ◽  
Late Antique ◽  
Public Monuments ◽  
The One ◽  
Independent Existence ◽  
Res Publica

Little more than a decade after Constantine's conversion to Christianity the ancient gods and goddesses of the Graeco-Roman pantheon ceased to appear upon the official coinage and public monuments of the Empire. The personifications—Victoria, Virtus, Pax, Libertas, Securitas, etc., and the ‘geographical’ figures of Res Publica, Roma, Tellus, cities, countries, and tribes—remained. Yet some of these had, up to that very time, received, like the Olympians, their shrines and altars and other honours associated with pagan cultus; and we ask ourselves how it was that a Christian State, while rejecting the one, could retain and ‘baptize’ the other. The answer to this question, which involves the whole complex problem of the nature of pagan religious belief under the later Empire, can only be tentatively suggested here. The pantheon had eventually to go because its denizens had possessed, for the great majority of pagans, a real, objective, and independent existence.

scholarly journals Ensemble Sensitivity Analysis for Mesoscale Forecasts of Dryline Convection Initiation

2016 ◽  
Vol 144 (11) ◽  
pp. 4161-4182 ◽  
Author(s):  
Aaron J. Hill ◽  
Christopher C. Weiss ◽  
Brian C. Ancell
Keyword(s):  
Sensitivity Analysis ◽  
Time Frame ◽  
Short Wave ◽  
Ensemble Member ◽  
Cold Pool ◽  
Dynamic Features ◽  
Wave Trough ◽  
Antecedent Precipitation ◽  
Non Gaussian ◽  
Convection Initiation

Abstract Two cases of dryline convection initiation (CI) over north Texas have been simulated (3 April 2012 and 15 May 2013) from a 50-member WRF-DART ensemble adjustment Kalman filter (EAKF) ensemble. In this study, ensemble sensitivity analysis (ESA) is applied to a convective forecast metric, maximum composite reflectivity (referred to as the response function), as a simple proxy for CI to analyze dynamic mesoscale sensitivities at the surface and aloft. Analysis reveals positional and magnitude sensitivities related to the strength and placement of important dynamic features. Convection initiation is sensitive to the evolving temperature and dewpoint fields upstream of the forecast response region in the near-CI time frame (0–12 h), prior to initiation. The sensitivity to thermodynamics is also manifest in the magnitude of dewpoint gradients along the dryline that triggers the convection. ESA additionally highlights the importance of antecedent precipitation and cold pool generation that modifies the pre-CI environment. Aloft, sensitivity of CI to a weak short-wave trough and capping inversion-level temperature is coherent, consistent, and traceable through the entire forecast period. Notwithstanding the (often) non-Gaussian distribution of ensemble member forecasts of convection, which violate the underpinnings of ESA theory, ESA is demonstrated to sufficiently identify regions that influence dryline CI. These results indicate an application of ESA for severe storm forecasting at operational centers and forecast offices as well as other mesoscale forecasting applications.

scholarly journals Studies on Amphibian Metamorphosis

1939 ◽  
Vol 16 (1) ◽  
pp. 96-120
Author(s):  
O. M. HELFF
Keyword(s):  
Great Majority ◽  
Gill Tissue ◽  
Shoulder Girdle ◽  
The Other ◽  
Histological Structure ◽  
Serial Sections ◽  
Stages Of Development ◽  
Amphibian Metamorphosis ◽  
The Right ◽  
Made In

(1) Opercular integument, homoplastically transplanted to the back and side of R. temporaria larvae, underwent a process of partial degeneration. The histolysis was not confined to any localized region of the transplant. (2) Autoplastic transplantation of opercular integument to the back and side produced a variety of results. Normal histological structure was maintained in certain transplants, generalized degeneration was observed in others, while in several instances localized histolysis resulting in perforation formation occurred. (3) Homoplastic and autoplastic transplantation of back and side skin to the opercular region resulted in histolysis and perforation formation in such transplants during larval involution. (4) The right forelimbs (in early stages of development) with attached portions of the shoulder girdle were extirpated in R. temporaria and B. bufo. During subsequent metamorphosis, normal opercular histolysis followed by perforation formation in many cases was observed. In most instances, serial sections of the peribranchial cavity revealed the absence of cutaneous glands. (5) Extirpation of the right forelimb only was made in the same two species. Opercular histolysis subsequently occurred in all instances, resulting in perforation formation in the great majority of cases during larval involution. In many of the B. bufo animals two separate perforations developed, one filled with limb stump and the other with gill tissue. (6) It is concluded that in R. temporaria a particular area of the operculum may in some individuals possess self-degenerative potentialities conducive to histolysis and perforation formation during metamorphosis. In both R. temporaria and B. bufo histolytic influences emanating from the atrophying gill tissue and the cutaneous glands of the forelimb are probably also responsible for opercular histolysis and perforation formation. Limb pressure must be considered a supplemental factor. (7) The results are discussed in general and attention called to the fact that opercular histolysis and perforation formation are "doubly assured" in some species and possibly even "triply assured" in others. Emphasis is placed on the evidently wide divergence between species as regards the particular combination of factors responsible for opercular histolysis and perforation formation. Apparently, no one explanation can serve to account for the phenomenon as it occurs in various species of anurans.

scholarly journals Social engineers and myth-busters: A comparative research on Lithuanian, Norwegian and Serbian language experts

2020 ◽  
pp. 292-344
Author(s):  
Vuk Vukotić
Keyword(s):  
News Media ◽  
Language Ideologies ◽  
Great Majority ◽  
Online News ◽  
The Other ◽  
Striking Similarity ◽  
The Public ◽  
Other Hand ◽  
The Public Sphere ◽  
The One

This article compares the language ideologies of language experts (both academic and non-academic) in online news media in Lithuania, Norway and Serbia. The results will reveal that language is understood in diametrically opposed ways amongst Lithuanian and Serbian academic experts on the one, and Norwegian academic experts on the other hand. Lithuanian and Serbian academic experts are influenced by modernist ideas of language as a single, homogenous entity, whose borders ideally match the borders of an ethnic group. Norwegian academic experts function in the public sphere as those who try to deconstruct the modernist notion of language by employing an understanding of language as a cognitive tool that performs communicative and other functions. On the other hand, non-academic experts in all the three countries exhibit a striking similarity in their language ideologies, as the great majority expresses modernist ideals of language.

scholarly journals Tularemia, Weather, and Rabbit Populations

1952 ◽  
Vol 25 (1-6) ◽  
pp. 351-382
Author(s):  
Ralph E. Yeatter ◽  
David H. Thompson
Keyword(s):  
Great Majority ◽  
The State ◽  
The Other ◽  
Risk Of Infection ◽  
Undue Risk ◽  
Different Parts

Tularemia, a disease of rabbits and hares (lagomorphs), rodents, and several other animals, is transmissible to man. In the period 1926- 1940. Illinois had more than 3,000 reported cases of human tularemia, about twice as many as any of the other states. The great majority of these Illinois cases were traceable to contact with cottontail rabbits. This paper deals with the relation of human tularemia in different parts of the state and in different years to weather, to the abundance of rabbits, and to some other aspects of its epidemiology. In analyzing the information on tularemia in Illinois, the writers have made an effort to determine the methods of management which would permit Illinois hunters to enjoy the sport of rabbit hunting without undue risk of infection.

Una aproximación empírica a la ­clasificación y traducción de las figuras retóricas en la publicidad

Babel ◽  
2011 ◽  
Vol 57 (1) ◽  
pp. 32-57 ◽  
Author(s):  
Maria Calzada Perez
Keyword(s):  
Empirical Investigation ◽  
Great Majority ◽  
Translation Studies ◽  
The Other ◽  
Translation Process ◽  
New Rhetoric ◽  
Rhetorical Figures ◽  
Ancient Times ◽  
The One

Since ancient times the suasive value of rhetorical figures has been vastly studied. In fact, Aristotle himself argued that the aim of rhetoric was not just to persuade but to find the best methods of persuasion (Aristotle, Retorica, ed. 1990). These methods have been frequently used in advertising, where they are employed to capture the consumer’s attention and, consequently, to sell the advertised product. However (despite the frequent appearance of rhetorical figures in advertising), there is a scarcity of studies on the role of these persuasive mechanisms in the translation of publicity. Bearing upon the “new rhetoric”, the present paper has a twofold purpose. On the one hand, it aims to import a clear taxonomy of rhetorical figures from advertising into translation studies and subsequently to illustrate the transfer of these figures. On the other hand, it analyses the behaviour of rhetorical figures in the translation process by means of an empirical investigation whose goal it is to further categorise them in a systematic and rational way. Drawing upon the seminal work of McQuarrie and his collaborators, the paper performs a quantitative analysis of a corpus of 120 matching pairs consisting of English advertisements and their existing Spanish counterparts. Results evidence that a great majority of rhetorical figures are “translated”, thus confirming the globalising tendencies of advertising.

scholarly journals Ensemble Sensitivity Tools for Assessing Extratropical Cyclone Intensity and Track Predictability

2013 ◽  
Vol 28 (5) ◽  
pp. 1133-1156 ◽  
Author(s):  
Minghua Zheng ◽  
Edmund K. M. Chang ◽  
Brian A. Colle
Keyword(s):  
Wave Packet ◽  
Great Plains ◽  
Rossby Wave ◽  
Short Wave ◽  
Empirical Orthogonal Functions ◽  
Track Forecast ◽  
Forecast Errors ◽  
Southern Great Plains ◽  
Cyclone Intensity ◽  
Wave Trough

Abstract This paper applies ensemble sensitivity analysis to a U.S. East Coast snowstorm on 26–28 December 2010 in a way that may be beneficial for an operational forecaster to better understand the forecast uncertainties. Sensitivity using the principal components of the leading empirical orthogonal functions (EOFs) on the 50-member European Centre for Medium-Range Weather Forecasts (ECMWF) ensemble identifies the sensitive regions and weather systems at earlier times associated with the cyclone intensity and track uncertainty separately. The 5.5-day forecast cyclone intensity uncertainty in the ECMWF ensemble is associated with trough and ridge systems over the northeastern Pacific and central United States, respectively, while the track uncertainty is associated with a short-wave trough over the southern Great Plains. Sensitivity based on the ensemble mean sea level pressure difference between two run cycles also suggests that the track's shift between the two cycles is linked with the initial errors in the short-wave trough over the southern Great Plains. The sensitivity approach is run forward in time using forward ensemble regression based on short-range forecast errors, which further confirms that the short-term error over the southern plains trough was associated with the shift in cyclone position between the two forecast cycles. A coherent Rossby wave packet originated from the central North Pacific 6 days before this snowstorm event. The sensitivity signals behave like a wave packet and exhibit the same group velocity of ~29° longitude per day, indicating that Rossby wave packets may have also amplified uncertainty in both the cyclone amplitude and track forecast.

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