scholarly journals Waterspout cloud top detection using MSG SEVIRI infrared brightness temperature over the northern Ionian Sea, Greece

2015 ◽  
Vol 12 (1) ◽  
pp. 45-49
Author(s):  
K. Papachristopoulou ◽  
I. T. Matsangouras ◽  
P. T. Nastos

Abstract. Waterspouts pose a significant threat for coastal areas, maritime activities and structures and thus their study is essential. They are frequently occurring in the Mediterranean Sea and particularly in the northern coasts. A vulnerable area of waterspout formation is the Ionian Sea according to recent research and especially the water body around Corfu Island, Greece. The Laboratory of Climatology and Atmospheric Environment of the University of Athens has assembled a detailed database of waterspout events, providing additional information such as location and time of these events; valuable information for the methodology followed. In this study, the waterspout data base concerns events from 20 March 2007 to 31 December 2013. Thus, a total of 74 events were recorded and catalogued on 47 days, as there were days with multiple waterspout events. The aim of this study is to investigate the temporal evolution of brightness temperature on tops of waterspout parent clouds that triggered the formation of single or multiple waterspout events, based on the aforementioned database. The cloud top temperature was assessed by using channel at 10.8 μm MSG SEVIRI Level 1.5 Image Data product. The minimum brightness temperature of the cloud top around the waterspout location for four different examined radiuses was estimated during 60 min prior to and after waterspout formation. Results are illustrated in terms of seasonal analysis. During autumn season a decrease of brightness temperature (colder values) was detected at waterspout parent cloud close to waterspout formation.

1979 ◽  
Vol 46 ◽  
pp. 368
Author(s):  
Clinton B. Ford

A “new charts program” for the Americal Association of Variable Star Observers was instigated in 1966 via the gift to the Association of the complete variable star observing records, charts, photographs, etc. of the late Prof. Charles P. Olivier of the University of Pennsylvania (USA). Adequate material covering about 60 variables, not previously charted by the AAVSO, was included in this original data, and was suitably charted in reproducible standard format.Since 1966, much additional information has been assembled from other sources, three Catalogs have been issued which list the new or revised charts produced, and which specify how copies of same may be obtained. The latest such Catalog is dated June 1978, and lists 670 different charts covering a total of 611 variables none of which was charted in reproducible standard form previous to 1966.


Robotica ◽  
2000 ◽  
Vol 18 (3) ◽  
pp. 299-303 ◽  
Author(s):  
Carl-Henrik Oertel

Machine vision-based sensing enables automatic hover stabilization of helicopters. The evaluation of image data, which is produced by a camera looking straight to the ground, results in a drift free autonomous on-board position measurement system. No additional information about the appearance of the scenery seen by the camera (e.g. landmarks) is needed. The technique being applied is a combination of the 4D-approach with two dimensional template tracking of a priori unknown features.


2021 ◽  
Author(s):  
ADRIANA W. (AGNES) BLOM-SCHIEBER ◽  
WEI GUO ◽  
EKTA SAMANI ◽  
ASHIS BANERJEE

A machine learning approach to improve the detection of tow ends for automated inspection of fiber-placed composites is presented. Automated inspection systems for automated fiber placement processes have been introduced to reduce the time it takes to inspect plies after they are laid down. The existing system uses image data from ply boundaries and a contrast-based algorithm to locate the tow ends in these images. This system fails to recognize approximately 10% of the tow ends, which are then presented to the operator for manual review, taking up precious time in the production process. An improved tow end detection algorithm based on machine learning is developed through a research project with the Boeing Advanced Research Center (BARC) at the University of Washington. This presentation shows the preprocessing, neural network and post‐processing steps implemented in the algorithm, and the results achieved with the machine learning algorithm. The machine learning algorithm resulted in a 90% reduction in the number of undetected tows compared to the existing system.


2020 ◽  
Vol 28 (18) ◽  
pp. 25730
Author(s):  
Wenwen Li ◽  
Feng Zhang ◽  
Yi-Ning Shi ◽  
Hironobu Iwabuchi ◽  
Mingwei Zhu ◽  
...  

2014 ◽  
Vol 53 (7) ◽  
pp. 1844-1857 ◽  
Author(s):  
Chunpeng Wang ◽  
Zhengzhao Johnny Luo ◽  
Xiuhong Chen ◽  
Xiping Zeng ◽  
Wei-Kuo Tao ◽  
...  

AbstractCloud-top temperature (CTT) is an important parameter for convective clouds and is usually different from the 11-μm brightness temperature due to non-blackbody effects. This paper presents an algorithm for estimating convective CTT by using simultaneous passive [Moderate Resolution Imaging Spectroradiometer (MODIS)] and active [CloudSat + Cloud–Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO)] measurements of clouds to correct for the non-blackbody effect. To do this, a weighting function of the MODIS 11-μm band is explicitly calculated by feeding cloud hydrometer profiles from CloudSat and CALIPSO retrievals and temperature and humidity profiles based on ECMWF analyses into a radiation transfer model. Among 16 837 tropical deep convective clouds observed by CloudSat in 2008, the averaged effective emission level (EEL) of the 11-μm channel is located at optical depth ~0.72, with a standard deviation of 0.3. The distance between the EEL and cloud-top height determined by CloudSat is shown to be related to a parameter called cloud-top fuzziness (CTF), defined as the vertical separation between −30 and 10 dBZ of CloudSat radar reflectivity. On the basis of these findings a relationship is then developed between the CTF and the difference between MODIS 11-μm brightness temperature and physical CTT, the latter being the non-blackbody correction of CTT. Correction of the non-blackbody effect of CTT is applied to analyze convective cloud-top buoyancy. With this correction, about 70% of the convective cores observed by CloudSat in the height range of 6–10 km have positive buoyancy near cloud top, meaning clouds are still growing vertically, although their final fate cannot be determined by snapshot observations.


Author(s):  
Cornetta L. Mosley

Purpose A comprehensive aural rehabilitation (AR) program incorporates sensory management, perceptual training, counseling, and instruction. However, the process of designing and implementing such a program is inconsistent across clinical sites, and additional information regarding the use of teleaudiology to implement AR services is needed. The purpose of this clinical focus article is to describe the process of creating and implementing a comprehensive teleaudiology AR program for older adults who use cochlear implants (CIs) at the University of South Alabama (USA) Speech & Hearing Center. Conclusions A comprehensive teleaudiology AR program may be successfully designed and implemented for older adult populations. Information provided in this clinical focus article may serve as a guide or example for other trained health care professionals looking to create an in-person or telehealth AR program for older adults who use CIs. Supplemental Material https://doi.org/10.23641/asha.16755289


Author(s):  
ALFRED MAROYI

Helichrysum longifolium and Helichrysum pedunculatum have a long history of medicinal use, particularly managing wounds acquired during male circumcision rites in South Africa. There is a need to evaluate the existence of any correlation between the ethnomedicinal applications, the phytochemistry and pharmacological properties of the species. Therefore, in this review, analyses of the botanical, medicinal, and chemical and biological activities of H. longifolium and H. pedunculatum are presented as well as exploring the potential of the two species as important sources of health and pharmaceutical products. Information on the botany, medicinal uses, and phytochemistry and biological activities of H. longifolium and H. pedunculatum was assembled from several internet sources which included Scopus, Google Scholar, Elsevier, Science Direct, Web of Science, PubMed, SciFinder, and BMC. Additional information was sourced from journal articles, scientific reports, theses, books, and book chapters obtained from the University library. This study showed that alkaloids, flavonoids, linoleic acid, oleic acid, phenol, proanthocyanidin, saponins, and tannins have been identified from the leaves of H. longifolium and H. pedunculatum. The pharmacological research showed that H. longifolium and H. pedunculatum extracts and compounds isolated from the species have antibacterial, antifungal, anti-inflammatory, antioxidant, antiplasmodial, antiprotozoal, and cytotoxicity activities. For local communities to use H. longifolium and H. pedunculatum extracts with confidence as herbal medicines, there is a need for extensive phytochemical and pharmacological studies. Further research is required to establish the safety profiles of different H. longifolium and H. pedunculatum preparations.


Author(s):  
L Buckley-Johnstone ◽  
M Harmon ◽  
R Lewis ◽  
C Hardwick ◽  
R Stock

This paper describes two methods, carried out at two different test scales, for assessing the friction modifier performance. Study A used the wear data from a full-scale rig test at the voestalpine Schienen GmbH and compared it with the wear data from twin disc tests using the SUROS test machine at the University of Sheffield. Study B compared the ‘retentivity’ data, from a full-scale rig at the University of Sheffield, with the data from the SUROS tests. Study A concluded that a good correlation existed between the two scales although assumptions made in the full-scale contact calculation introduce a large spread into the results. There was a greater correlation between the two data sets at more severe contact conditions. Study B showed a different baseline coefficient of traction between the two scales and that a longer test length is required to fully evaluate the ‘retention’ of the friction modifier on the full-scale rig. The paper expands on a previous conference presentation on the same subject. Additional information on the test procedure and test rigs is included here. Surface and subsurface analyses of the SUROS test samples have also been added. The analyses have shown that applying the friction modifier leads to a similar wear mechanism as for the dry contact, but the wear is less severe and there is less subsurface deformation. A discussion describing the differences in test scales and comparing lab tests to field operation is also included.


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