scholarly journals Cold‐pool‐driven convective initiation: using causal graph analysis to determine what convection‐permitting models are missing

2020 ◽  
Vol 146 (730) ◽  
pp. 2205-2227 ◽  
Author(s):  
Mirjam Hirt ◽  
George C. Craig ◽  
Sophia A. K. Schäfer ◽  
Julien Savre ◽  
Rieke Heinze
Keyword(s):  
Cold Pool ◽  
Graph Analysis ◽  
Convective Initiation ◽  
Causal Graph

scholarly journals Causal graph analysis of COVID-19 observational data in German districts reveals effects of determining factors on reported case numbers

PLoS ONE ◽  
2021 ◽  
Vol 16 (5) ◽  
pp. e0237277
Author(s):  
Edgar Steiger ◽  
Tobias Mussgnug ◽  
Lars Eric Kroll
Keyword(s):  
Negative Binomial ◽  
Graphical Representation ◽  
Driving Forces ◽  
Public Awareness ◽  
Causal Effects ◽  
Graph Analysis ◽  
Residential Areas ◽  
Robert Koch Institute ◽  
Causal Graph ◽  
Determining Factors

Several determinants are suspected to be causal drivers for new cases of COVID-19 infection. Correcting for possible confounders, we estimated the effects of the most prominent determining factors on reported case numbers. To this end, we used a directed acyclic graph (DAG) as a graphical representation of the hypothesized causal effects of the determinants on new reported cases of COVID-19. Based on this, we computed valid adjustment sets of the possible confounding factors. We collected data for Germany from publicly available sources (e.g. Robert Koch Institute, Germany’s National Meteorological Service, Google) for 401 German districts over the period of 15 February to 8 July 2020, and estimated total causal effects based on our DAG analysis by negative binomial regression. Our analysis revealed favorable effects of increasing temperature, increased public mobility for essential shopping (grocery and pharmacy) or within residential areas, and awareness measured by COVID-19 burden, all of them reducing the outcome of newly reported COVID-19 cases. Conversely, we saw adverse effects leading to an increase in new COVID-19 cases for public mobility in retail and recreational areas or workplaces, awareness measured by searches for “corona” in Google, higher rainfall, and some socio-demographic factors. Non-pharmaceutical interventions were found to be effective in reducing case numbers. This comprehensive causal graph analysis of a variety of determinants affecting COVID-19 progression gives strong evidence for the driving forces of mobility, public awareness, and temperature, whose implications need to be taken into account for future decisions regarding pandemic management.

Cold pool driven convective initiation: How can we improve its representation in km-scale models?

2020 ◽  
Author(s):  
Mirjam Hirt ◽  
George Craig
Keyword(s):  
Positive Impact ◽  
Potential Temperature ◽  
Horizontal Wind ◽  
Cold Pool ◽  
Model Resolution ◽  
Convective Initiation ◽  
Cold Pools ◽  
Scale Models ◽  
Gust Fronts ◽  
Gust Front

<p>Cold pools are essential for organizing convection and play a particular role in convective initiation in the afternoon and evening. Both aspects are deficient in current convection-permitting models and a better representation of cold pools is likely necessary to overcome these deficiencies. In a recent investigation, we identified several sensitivities of cold pool driven convective initiation to model resolution within hectometer simulations. In particular, a causal graph analysis has revealed that the dominant impact of model resolution on convective initiation is due to too weak gust front vertical velocities. This implies that cold pool gust fronts in km-scale models are too weak to trigger sufficient new convection.</p><p>To address this deficiency, we develop a parameterization for the convection-permitting COSMO model to improve the representation of cold pool gust fronts. We use the potential temperature gradient to identify cold pool gust fronts and enhance vertical wind tendencies within these gust front regions.  Also, we perturb horizontal wind tendencies to yield 3d non-divergent perturbations.  This parameterization strengthens gust front circulations and thereby enhances cold pool driven convective initiation. Consequently, precipitation is amplified and becomes more organized in the afternoon and evening. This improves the diurnal cycle of precipitation and also has some positive impact on the spatial distribution as quantified by the fraction skill score. Furthermore, cold pools themselves are strengthened, which can further enhance the gust front circulations, giving rise to a feedback loop. </p>

Interactions between Physics Diversity and Multiscale Initial Condition Perturbations for Storm-Scale Ensemble Forecasting

2020 ◽  
Vol 148 (8) ◽  
pp. 3549-3565
Author(s):  
Aaron Johnson ◽  
Xuguang Wang
Keyword(s):  
Spatial Scale ◽  
Lead Time ◽  
Cold Pool ◽  
Small Scale ◽  
Lead Times ◽  
Synoptic Scale ◽  
Convective Initiation ◽  
Forecast Performance ◽  
Forecast Lead Time

Abstract This study investigates impacts on convection-permitting ensemble forecast performance of different methods of generating the ensemble IC perturbations in the context of simultaneous physics diversity among the ensemble members. A total of 10 convectively active cases are selected for a systematic comparison of different methods of perturbing IC perturbations in 10-member convection-permitting ensembles, both with and without physics diversity. These IC perturbation methods include simple downscaling of coarse perturbations from a global model (LARGE), perturbations generated with ensemble data assimilation directly on the multiscale domain (MULTI), and perturbations generated using each method with small scales filtered out as a control. MULTI was found to be significantly more skillful than LARGE at early lead times in all ensemble physics configurations, with the advantage of MULTI gradually decreasing with increasing forecast lead time. The advantage of MULTI, relative to LARGE, was reduced but not eliminated by the presence of physics diversity because of the extra ensemble spread that the physics diversity provided. The advantage of MULTI, relative to LARGE, was also reduced by filtering the IC perturbations to a commonly resolved spatial scale in both ensembles, which highlights the importance of flow-dependent small-scale (<~10 m) IC perturbations in the ensemble design. The importance of the physics diversity, relative to the IC perturbation method, depended on the spatial scale of interest, forecast lead time, and the meteorological characteristics of the forecast case. Such meteorological characteristics include the strength of synoptic-scale forcing, the role of cold pool interactions, and the occurrence of convective initiation or dissipation.

scholarly journals Wave Disturbances and Their Role in the Maintenance, Structure, and Evolution of a Mesoscale Convection System

2019 ◽  
Vol 77 (1) ◽  
pp. 51-77 ◽  
Author(s):  
Shushi Zhang ◽  
David B. Parsons ◽  
Yuan Wang
Keyword(s):  
Great Plains ◽  
Wave Energy ◽  
Deep Convection ◽  
Inversion Layer ◽  
Mesoscale Convective System ◽  
Vertical Shear ◽  
Cold Pool ◽  
Convective System ◽  
Convective Initiation ◽  
Mesoscale Convective

Abstract This study investigates a nocturnal mesoscale convective system (MCS) observed during the Plains Elevated Convection At Night (PECAN) field campaign. A series of wavelike features were observed ahead of this MCS with extensive convective initiation (CI) taking place in the wake of one of these disturbances. Simulations with the WRF-ARW Model were utilized to understand the dynamics of these disturbances and their impact on the MCS. In these simulations, an “elevated bore” formed within an inversion layer aloft in response to the layer being lifted by air flowing up and over the cold pool. As the bore propagated ahead of the MCS, the lifting created an environment more conducive to deep convection allowing the MCS to discretely propagate due to CI in the bore’s wake. The Scorer parameter was somewhat favorable for trapping of this wave energy, although aspects of the environment evolved to be consistent with the expectations for an n = 2 mode deep tropospheric gravity wave. A bore within an inversion layer aloft is reminiscent of disturbances predicted by two-layer hydraulic theory, contrasting with recent studies that suggest bores are frequently initiated by the interaction between the flow within stable nocturnal boundary layer and convectively generated cold pools. Idealized simulations that expand upon this two-layer approach with orography and a well-mixed layer below the inversion suggest that elevated bores provide a possible mechanism for daytime squall lines to remove the capping inversion often found over the Great Plains, particularly in synoptically disturbed environments where vertical shear could create a favorable trapping of wave energy.

Inspiration Space

2019 ◽  
Vol 1 (1) ◽  
Author(s):  
Milene GONÇALVES ◽  
Katja THORING ◽  
Roland M. MUELLER ◽  
Petra BADKE-SCHAUB ◽  
Pieter DESMET
Keyword(s):  
Learning Environments ◽  
Physical Environment ◽  
Educational Institutions ◽  
Expert Interviews ◽  
Learning Spaces ◽  
Causal Graph ◽  
Physical Environments ◽  
Creative Learning ◽  
Design Students

Building on the assumption that the physical environment can have an influence on the creativity of designers and design students in particular, the aim of this paper is to provide theoretical propositions and evidences for this relationship. We develop various propositions about the influence of physical environments on creativity, based on eight expert interviews and supported by literature. A particular focus was given to the environments of design educational institutions. We present a summary of the main insights and visualize the developed propositions as a causal graph addressing how space influences creativity. These propositions can be regarded as a first step towards a theory of creativity-supporting learning environments and they can serve as a reference when designing or adjusting creative learning spaces.

Penggunaan Social Stories untuk Menurunkan Perilaku Nonadaptif Saat Berada dalam Kendaraan Bagi Autisme Dewasa

2020 ◽  
Vol 1 (2) ◽  
pp. 103
Author(s):  
Markus Nanang Irawan ◽  
Sri Widyawati
Keyword(s):  
Social Interaction ◽  
Behavior Problems ◽  
Adaptive Behavior ◽  
Behavioral Problems ◽  
Research Method ◽  
Social Stories ◽  
Steering Wheel ◽  
Graph Analysis ◽  
Adult Autism ◽  
The Individual

<pre><span>Individuals autism often have non-adaptive behavioral problems because of their barriers in communication and social interaction. The problem of non-adaptive behavior is often a nuisance to others because its appearance is not appropriate and not in accordance with the environment, age, and expectations of responsibility. One case of non-adaptive behavior that arises is the behavior while in a vehicle where the individual shows the behavior of singing loudly, knocking windows, pinching the driver, even holding the steering wheel. Based on these problems, this study aims to reduce non-adaptive behavior while in a vehicle. Participant is an adult autism. The research method is experiment by giving Social Stories to participants before riding the vehicle then recording to the possibility appearance of non adaptive behavior. The results of graph analysis showed a decrease in non adaptive behavior of adult autism adults while in a vehicle. This study became one of the important studies because it tries to understand the dynamics of behavior problems of individual autisme in adulthood.<strong></strong></span></pre><pre><span> </span></pre>

Fast Planning Through Planning Graph Analysis.

1995 ◽  
Author(s):  
Avrim L. Blum ◽  
Merrick L. Furst
Keyword(s):  
Graph Analysis ◽  
Planning Graph

What´s driving dermatology: Contribution title analysis of the largest German Dermatology Congress 2019 (Preprint)

2020 ◽  
Author(s):  
Robert Kaczmarczyk ◽  
Felix Bauerdorf ◽  
Alexander Zink
Keyword(s):  
Network Analysis ◽  
Annual Meeting ◽  
Research Network ◽  
Graph Analysis ◽  
Network Graph ◽  
Research Topics ◽  
German Speaking ◽  
Specialist Groups ◽  
Community Meeting ◽  
High Diversity

BACKGROUND Every two years, German-speaking dermatologic specialist groups gather in Berlin to share the latest developments at Germany´s largest dermatologic conference, the Annual Meeting of the Germany Society of Dermatology (DDG). Because this conference has a lasting effect on dermatologic practice and research, understanding what is moving the specialist groups means understanding what is driving dermatology in Germany. OBJECTIVE The objective of the article is to introduce the medical scientific community to a data visualization method, which will help understand more sophisticated data analysis and processing approaches in the future. METHODS We used word network analysis to compile and visualize the information embedded in the contribution titles to the DDG Annual Meeting in 2019. We extracted words, contributing cities and inter-connections. The data was standardized, visualized using network graphs and analyzed using common network analysis parameters. RESULTS A total of 5509 words were extracted from 1150 contribution titles. The most frequently used words were “therapy”, “patients”, and “psoriasis”. The highest number of contributions came from Hamburg, Berlin and Munich. High diversity in research topics was found, as well as a well-connected research network. CONCLUSIONS Focus of the well-connected German-speaking dermatology community meeting 2019 was patient and therapy centered and lies especially on the diseases psoriasis and melanoma. Network graph analysis can provide helpful insights and help planning future congresses. It can facilitate the choice which contributors to include as imbalances become apparent. Moreover, it can help distributing the topics more evenly across the whole dermatologic spectrum.

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