scholarly journals A Characterisation of Alpine Mesocyclone Occurrence

2021 ◽  
Author(s):  
Monika Feldmann ◽  
Urs Germann ◽  
Marco Gabella ◽  
Alexis Berne
Keyword(s):  
Temporal Distribution ◽  
Radar Data ◽  
Detection Algorithm ◽  
Data Set ◽  
Additional Information ◽  
Detection And Tracking ◽  
Synoptic Weather ◽  
Southern Side ◽  
The Alps ◽  
Spatio Temporal

Abstract. This work presents a characterization of mesocyclone occurrence and frequency in the Alpine region, as observed from the Swiss operational radar network. Five years of radar data are processed with a thunderstorm detection and tracking algorithm and subsequently with a mesocyclone detection algorithm. A quality assessment of the radar domain provides additional information on the reliability of the tracking algorithms throughout the domain. The resulting data set provides the first insight into the spatio-temporal distribution of mesocyclones in the Swiss domain, with a more detailed focus on the influence of synoptic weather, diurnal cycle and terrain. Both on the northern and southern side of the Alps mesocyclonic signatures in thunderstorms are frequent. The regions with highest occurrence are predominantly the Southern Prealps and to a lesser degree the Northern Prealps. The parallels to hail research over the same region are discussed.

scholarly journals A characterisation of Alpine mesocyclone occurrence

2021 ◽  
Vol 2 (4) ◽  
pp. 1225-1244
Author(s):  
Monika Feldmann ◽  
Urs Germann ◽  
Marco Gabella ◽  
Alexis Berne
Keyword(s):  
Radar Data ◽  
Detection Algorithm ◽  
Data Set ◽  
Additional Information ◽  
Detection And Tracking ◽  
Synoptic Weather ◽  
Radar Network ◽  
Southern Side ◽  
The Alps ◽  
Insight Into

Abstract. This work presents a characterisation of mesocyclone occurrence and frequency in the Alpine region, as observed from the Swiss operational radar network; 5 years of radar data are processed with a thunderstorm detection and tracking algorithm and subsequently with a new mesocyclone detection algorithm. A quality assessment of the radar domain provides additional information on the reliability of the tracking algorithms throughout the domain. The resulting data set provides the first insight into the spatiotemporal distribution of mesocyclones in the Swiss domain, with a more detailed focus on the influence of synoptic weather, diurnal cycle and terrain. Both on the northern and southern side of the Alps mesocyclonic signatures in thunderstorms occur regularly. The regions with the highest occurrence are predominantly the Southern Prealps and to a lesser degree the Northern Prealps. The parallels to hail research over the same region are discussed.

Interfacial Interactions

2010 ◽  
pp. 128-177
Author(s):  
Wei Ge ◽  
Ning Yang ◽  
Wei Wang ◽  
Jinghai Li
Keyword(s):  
Temporal Distribution ◽  
Gravitational Potential Energy ◽  
Immersed Boundary ◽  
Immersed Boundary Methods ◽  
Additional Information ◽  
Mesoscale Structures ◽  
Computational Fluid Dynamics Cfd ◽  
Spatio Temporal ◽  
Drag Models ◽  
The Stability

The drag interaction between gas and solids not only acts as a driving force for solids in gas-solids flows but also plays as a major role in the dissipation of the energy due to drag losses. This leads to enormous complexities as these drag terms are highly non-linear and multiscale in nature because of the variations in solids spatio-temporal distribution. This chapter provides an overview of this important aspect of the hydrodynamic interactions between the gas and solids and the role of spatio-temporal heterogeneities on the quantification of this drag force. In particular, a model is presented which introduces a mesoscale description into two-fluid models for gas-solids flows. This description is formulated in terms of the stability of gas-solids suspension. The stability condition is, in turn, posed as a minimization problem where the competing factors are the energy consumption required to suspend and transport the solids and their gravitational potential energy. However, the lack of scale-separation leads to many uncertainties in quantifying mesoscale structures. The authors have incorporated this model into computational fluid dynamics (CFD) simulations which have shown improvements over traditional drag models. Fully resolved simulations, such as those mentioned in this chapter and the subject of a later chapter on Immersed Boundary Methods, can be used to obtain additional information about these mesoscale structures. This can be used to formulate better constitutive equations for continuum models.

scholarly journals Using treemaps for variable selection in spatio-temporal visualisation

2008 ◽  
Vol 7 (3-4) ◽  
pp. 210-224 ◽  
Author(s):  
Aidan Slingsby ◽  
Jason Dykes ◽  
Jo Wood
Keyword(s):  
Variable Selection ◽  
Visual Analysis ◽  
Temporal Distribution ◽  
Temporal Data ◽  
Data Set ◽  
Raster Maps ◽  
Categorical Attributes ◽  
Interactive Interfaces ◽  
Road Maps ◽  
Spatio Temporal

We demonstrate and reflect upon the use of enhanced treemaps that incorporate spatial and temporal ordering for exploring a large multivariate spatio-temporal data set. The resulting data-dense views summarise and simultaneously present hundreds of space-, time-, and variable-constrained subsets of a large multivariate data set in a structure that facilitates their meaningful comparison and supports visual analysis. Interactive techniques allow localised patterns to be explored and subsets of interest selected and compared with the spatial aggregate. Spatial variation is considered through interactive raster maps and high-resolution local road maps. The techniques are developed in the context of 42.2 million records of vehicular activity in a 98 km2 area of central London and informally evaluated through a design used in the exploratory visualisation of this data set. The main advantages of our technique are the means to simultaneously display hundreds of summaries of the data and to interactively browse hundreds of variable combinations with ordering and symbolism that are consistent and appropriate for space- and time-based variables. These capabilities are difficult to achieve in the case of spatio-temporal data with categorical attributes using existing geovisualisation methods. We acknowledge limitations in the treemap representation but enhance the cognitive plausibility of this popular layout through our two-dimensional ordering algorithm and interactions. Patterns that are expected (e.g. more traffic in central London), interesting (e.g. the spatial and temporal distribution of particular vehicle types) and anomalous (e.g. low speeds on particular road sections) are detected at various scales and locations using the approach. In many cases, anomalies identify biases that may have implications for future use of the data set for analyses and applications. Ordered treemaps appear to have potential as interactive interfaces for variable selection in spatio-temporal visualisation.

scholarly journals Fall Detection with CNN-Casual LSTM Network

Information ◽  
2021 ◽  
Vol 12 (10) ◽  
pp. 403
Author(s):  
Jiang Wu ◽  
Jiale Wang ◽  
Ao Zhan ◽  
Chengyu Wu
Keyword(s):  
Fall Detection ◽  
Detection Algorithm ◽  
Personal Privacy ◽  
Data Set ◽  
The Public ◽  
The Neural Network ◽  
Public Data ◽  
Spatio Temporal ◽  
Axis Rotation ◽  
Lstm Network

Falls are one of the main causes of elderly injuries. If the faller can be found in time, further injury can be effectively avoided. In order to protect personal privacy and improve the accuracy of fall detection, this paper proposes a fall detection algorithm using the CNN-Casual LSTM network based on three-axis acceleration and three-axis rotation angular velocity sensors. The neural network in this system includes an encoding layer, a decoding layer, and a ResNet18 classifier. Furthermore, the encoding layer includes three layers of CNN and three layers of Casual LSTM. The decoding layer includes three layers of deconvolution and three layers of Casual LSTM. The decoding layer maps spatio-temporal information to a hidden variable output that is more conducive relative to the work of the classification network, which is classified by ResNet18. Moreover, we used the public data set SisFall to evaluate the performance of the algorithm. The results of the experiments show that the algorithm has high accuracy up to 99.79%.

Stratigraphy of architectural elements in a buried volcanic system and implications for hydrocarbon exploration

2017 ◽  
Vol 5 (3) ◽  
pp. SK141-SK159 ◽  
Author(s):  
Alan Patrick Bischoff ◽  
Andrew Nicol ◽  
Mac Beggs
Keyword(s):  
Temporal Distribution ◽  
Large Data ◽  
Sedimentary Basins ◽  
Building Blocks ◽  
Hydrocarbon Exploration ◽  
Coarse Grained ◽  
Data Set ◽  
Volcanic System ◽  
Architectural Elements ◽  
Spatio Temporal

The interaction between magmatism and sedimentation creates a range of petroleum plays at different stratigraphic levels due to the emplacement and burial of volcanoes. This study characterizes the spatio-temporal distribution of the fundamental building blocks (i.e., architectural elements) of a buried volcano and enclosing sedimentary strata to provide insights for hydrocarbon exploration in volcanic systems. We use a large data set of wells and seismic reflection surveys from the offshore Taranaki Basin, New Zealand, compared with outcropping volcanic systems worldwide to demonstrate the local impacts of magmatism on the evolution of the host sedimentary basin and petroleum system. We discover the architecture of Kora volcano, a Miocene andesitic polygenetic stratovolcano that is currently buried by more than 1000 m of sedimentary strata and hosts a subcommercial discovery within volcanogenic deposits. The 22 individual architectural elements have been characterized within three main stratigraphic sequences of the Kora volcanic system. These sequences are referred to as premagmatic (predate magmatism), synmagmatic (defined by the occurrence of intrusive, eruptive, and sedimentary architectural elements), and postmagmatic (degradation and burial of the volcanic structures after magmatism ceased). Potential petroleum plays were identified based on the distribution of the architectural elements and on the geologic circumstances resulting from the interaction between magmatism and sedimentation. At the endogenous level, emplacement of magma forms structural traps, such as drag folds and strata jacked up above intrusions. At the exogenous level, syneruptive, intereruptive, and postmagmatic processes mainly form stratigraphic and paleogeomorphic traps, such as interbedded volcano-sedimentary deposits, and upturned pinchout of volcanogenic and nonvolcanogenic coarse-grained deposits onto the volcanic edifice. Potential reservoirs are located at systematic vertical and lateral distances from eruptive centers. We have determined that identifying the architectural elements of buried volcanoes is necessary for building predictive models and for derisking hydrocarbon exploration in sedimentary basins affected by magmatism.

scholarly journals Seasonality of Vertical Structure in Radar-Observed Precipitation over Southern Switzerland

2013 ◽  
Vol 14 (1) ◽  
pp. 318-330 ◽  
Author(s):  
James V. Rudolph ◽  
Katja Friedrich
Keyword(s):  
Vertical Structure ◽  
Winter Season ◽  
Radar Data ◽  
Convective Precipitation ◽  
Similar Amount ◽  
Winter Type ◽  
Southern Side ◽  
The Alps ◽  
Precipitation Events

Abstract Operational radar data reveal that precipitation systems occurring on the southern side of the Alps near Locarno, Switzerland, follow seasonal patterns of vertical reflectivity structure. Storms occurring in summer are more convective than winter season storms as indicated by more frequent observation of reflectivity at higher altitudes during summer. Individual precipitation events occurring year-round are classified by comparison to average seasonal vertical reflectivity structure. Seasonal classification of individual storms reveals a transition between winter- and summer-type storms during spring and fall that follows changes in average daily surface temperature. In addition to distinct vertical structure, summer- and winter-type storms have differences in duration, intensity, and interval between storms. Although summer- and winter-type storms result in a similar amount of total precipitation, summer-type storms have shorter duration, and therefore greater intensity. The dependence of storm types on temperature has implications for intensification of the hydrologic cycle due to climate change. Warmer winter, spring, or fall surface temperatures may affect average precipitation intensity by increasing the number of days per year that experience more intense convective precipitation while decreasing the probability of less intense stratiform precipitation.

scholarly journals A climatology of sub-seasonal temporal clustering of extreme precipitation in Switzerland and its impacts

2021 ◽  
Author(s):  
Alexandre Tuel ◽  
Olivia Martius
Keyword(s):  
Extreme Precipitation ◽  
Precipitation Extremes ◽  
Flood Events ◽  
Temporal Clustering ◽  
Extreme Precipitation Events ◽  
Southern Side ◽  
Northern Side ◽  
The Alps ◽  
Spatio Temporal ◽  
Seasonal Time Scale

Abstract. The successive occurrence of extreme precipitation events on a sub-seasonal time-scale can lead to large precipitation accumulations, a classic trigger of flood events. Here we analyse sub-seasonal clustering in Switzerland, first characterizing the tendency of precipitation extremes to cluster in time for each season separately, and second, linking the occurrence of persistent flood events to sub-seasonal clusters of precipitation extremes. We find a distinct spatio-temporal pattern in temporal clustering behavior of precipitation extremes, with temporal clustering occurring on the northern side of the Alps in winter, and on their southern side in fall. In winter, the magnitude of precipitation extremes is generally lower, and much of the precipitation falls as snow, therefore temporal clusters contribute little to the occurrence of persistent flood events. In fall, however, temporal clusters associated with large precipitation accumulations over the southern Alps are found to be almost systematically followed by floods. In addition, discharge magnitudes decrease more slowly after clustered extremes.

scholarly journals Spatio-Temporal Clustering of Sarawak Malaysia Total Protected Area Visitors

2021 ◽  
Vol 13 (21) ◽  
pp. 11618
Author(s):  
Abang Zainoren Abang Abdurahman ◽  
Syerina Azlin Md Nasir ◽  
Wan Fairos Wan Yaacob ◽  
Serah Jaya ◽  
Suhaili Mokhtar
Keyword(s):  
National Parks ◽  
Temporal Distribution ◽  
Temporal Analysis ◽  
Minimum Variance ◽  
Additional Information ◽  
Spatial And Temporal Analysis ◽  
Spatio Temporal ◽  
Underlying Trend ◽  
Very High ◽  
Minimum Variance Method

Based on data of visitors to national parks, nature reserves and wildlife sanctuaries in Sarawak, this study’s objective is to use the spatial and temporal analysis to describe the underlying trend and temporal pattern of local and foreign visitors and ultimately infer the temporal distribution of visitors to 18 different TPAs. The second aim of the study is to cluster the visitors according to the location of TPAs using Wards hierarchical clustering method. By comparing average monthly visitors’ count, we observed that the average number of monthly visitors significantly reflects the distribution concentration of visitors based on the spatial map. Findings indicate that the monthly distributions of local and foreign visitors differ according to different TPAs. The spatial and temporal analysis found that local visitors’ arrival is high at the end of the year while foreign visitors showed significant arrival during the months of July, August and September. The Wards minimum variance method was able to cluster TPAs local and foreign visitors into very high, high, medium and low visitor area. This study provides additional information that could contribute to identifying the periods of highest visitor pressure, design measures to manage the concentration of visitors and improve the overall visitors’ experience. The findings of the study are also important to respective local authorities in providing information for planning and monitoring tourism in TPAs. Consecutively, this will ensure sustainability of TPAs resources while protecting their biodiversity.

scholarly journals A Calibration/Disaggregation Coupling Scheme for Retrieving Soil Moisture at High Spatio-Temporal Resolution: Synergy between SMAP Passive Microwave, MODIS/Landsat Optical/Thermal and Sentinel-1 Radar Data

Sensors ◽  
2021 ◽  
Vol 21 (21) ◽  
pp. 7406
Author(s):  
Nitu Ojha ◽  
Olivier Merlin ◽  
Abdelhakim Amazirh ◽  
Nadia Ouaadi ◽  
Vincent Rivalland ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Soil Moisture ◽  
Temporal Resolution ◽  
Radar Data ◽  
Passive Microwave ◽  
Field Scale ◽  
Data Set ◽  
Thermal Data ◽  
Spatio Temporal

Soil moisture (SM) data are required at high spatio-temporal resolution—typically the crop field scale every 3–6 days—for agricultural and hydrological purposes. To provide such high-resolution SM data, many remote sensing methods have been developed from passive microwave, active microwave and thermal data. Despite the pros and cons of each technique in terms of spatio-temporal resolution and their sensitivity to perturbing factors such as vegetation cover, soil roughness and meteorological conditions, there is currently no synergistic approach that takes advantage of all relevant (passive, active microwave and thermal) remote sensing data. In this context, the objective of the paper is to develop a new algorithm that combines SMAP L-band passive microwave, MODIS/Landsat optical/thermal and Sentinel-1 C-band radar data to provide SM data at the field scale at the observation frequency of Sentinel-1. In practice, it is a three-step procedure in which: (1) the 36 km resolution SMAP SM data are disaggregated at 100 m resolution using MODIS/Landsat optical/thermal data on clear sky days, (2) the 100 m resolution disaggregated SM data set is used to calibrate a radar-based SM retrieval model and (3) the so-calibrated radar model is run at field scale on each Sentinel-1 overpass. The calibration approach also uses a vegetation descriptor as ancillary data that is derived either from optical (Sentinel-2) or radar (Sentinel-1) data. Two radar models (an empirical linear regression model and a non-linear semi-empirical formulation derived from the water cloud model) are tested using three vegetation descriptors (NDVI, polarization ratio (PR) and radar coherence (CO)) separately. Both models are applied over three experimental irrigated and rainfed wheat crop sites in central Morocco. The field-scale temporal correlation between predicted and in situ SM is in the range of 0.66–0.81 depending on the retrieval configuration. Based on this data set, the linear radar model using PR as a vegetation descriptor offers a relatively good compromise between precision and robustness all throughout the agricultural season with only three parameters to set. The proposed synergistical approach combining multi-resolution/multi-sensor SM-relevant data offers the advantage of not requiring in situ measurements for calibration.

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