Climatology and variability of cyclone clustering

2021 ◽  
Author(s):  
Chris Weijenborg ◽  
Thomas Spengler
Keyword(s):  
Diabatic Heating ◽  
Baroclinic Instability ◽  
Temporal Distance ◽  
Extratropical Cyclones ◽  
Eof Analysis ◽  
Apparent Contradiction ◽  
Atmospheric Rivers ◽  
Short Period ◽  
Spatio Temporal

<div> <div> <div> <p>The existence of cyclone clustering, the succession of multiple extratropical cyclones during a short period of time, indicates that the baroclinicity feeding these storms undergoes longer lasting episodic cycles supporting multiple cyclones. However, the generally accepted paradigm for baroclinic instability implies that individual cyclones reduce baroclinicity to support their growth. This apparent contradiction motivates our hypothesis that some cyclones within increase baroclinicity, yielding a pathway for cyclone clustering. A case study of the extreme storm Dagmar confirms that a particular sequence of storms culminating in a severe cyclone is due to the fact that the previous storms act to maintain or increase the background baroclinity along which the succeeding storms evolved. </p> <p>Using a new cyclone clustering diagnostic based on spatio-temporal distance between cyclone tracks, we analyse cyclone clustering globally for the period 1979 until 2016. We complement this analysis with a baroclinicity diagnostic based on the slope of isentropic surfaces. With the isentropic slope and its tendencies, the relative roles of diabatic and adiabatic effects associated with extra-tropical cyclones in maintaining baroclinicity are assessed. We present a climatological analysis of where and when cyclone clustering occurs. We compare these findings to composites of clustered and non-clustered cyclones to quantify how consistent the proposed clustering mechanism is and its relation to changes in the frequency of atmospheric rivers. We complement this with an EOF analysis to investigate the variability of the clusters and how it covaries with the jet and diabatic heating.</p> </div> </div> </div>

Can Extratropical Cyclones Increase Baroclinicty? A Pathway to Cyclone Clustering

2020 ◽  
Author(s):  
Chris Weijenborg ◽  
Thomas Spengler
Keyword(s):  
Life Cycle ◽  
Tropical Cyclones ◽  
Baroclinic Instability ◽  
Temporal Distance ◽  
Extratropical Cyclones ◽  
Apparent Contradiction ◽  
Cyclone Tracks ◽  
Spatio Temporal

<p>The existence of cyclone clustering, the succession of multiple cyclones in a short amount of time, indicates that the baroclinicity feeding these storms undergoes episodic cycles. With the generally accepted paradigm of baroclinic instability for extratropical cyclones, one would anticipate that clustering coincides with increased baroclinicity, though simultaneously individual cyclones reduce baroclinicity to maintain their growth. This apparent contradiction motivates our hypothesis that some cyclones increase baroclinicity, which could be a pathway for cyclone clustering.</p><p>Using a new cyclone clustering diagnostic based on spatio-temporal distance between cyclone tracks, we analyse cyclone clustering for the period 1979 until 2016. We complement this analysis with a baroclinity diagnostic, the slope of isentropic surfaces. With the isentropic slope and its tendencies, the relative roles of diabatic and adiabatic effects associated with extra-tropical cyclones in maintaining baroclinicity are assessed. We first present a case study, for which a sequence of cyclones culminated in severe cyclones due to the fact that one of the storms significantly increased the background baroclinity along which the succeeding storms evolved. The life cycle of these storms is discussed in terms of how the storm changes and uses its environment to attain its intensity. We compare these findings to composites of clustered and non-clustered cyclones to quantify how consistent the proposed clustering-mechanism is.</p>

Sensitivity of simulated warm conveyor belt associated with an extratropical cyclone to model resolution and treatment of cloud processes - a NAWDEX case study

2020 ◽  
Author(s):  
Anubhav Choudhary ◽  
Aiko Voigt
Keyword(s):  
Diabatic Heating ◽  
Conveyor Belt ◽  
Cloud Microphysics ◽  
Extratropical Cyclones ◽  
Model Resolution ◽  
New Class ◽  
Diabatic Processes ◽  
Fine Resolution ◽  
The Impact

<p>Previous work showed that simulations of extratropical cyclones and their intensity are significantly impacted by model resolution. This might be explained by the impact of resolution on cloud diabatic processes occurring within the warm conveyor belt (WCB), as these are linked to the strength of cyclones. To investigate this link, we move gradually from very coarse (80km) to very fine resolution (2.5km) simulations and study if there is a systematic impact of resolution on the simulated WCB processes. For this purpose, we analyse ICON simulations in a regional North Atlatnic setup for a specific case from the NAWDEX campaign -  cyclone Vladiana - that occurred on 23<sup>rd</sup> September, 2016. Furthermore, we compare simulations with 1- and 2- moment cloud microphysics and with explicit and parametrized convection. From these simulations WCB trajectories are calculated over 48 hours by means of the Lagranto tool and 1-hourly model output to sample cloud diabatic processes within the WCB. We find a systematic increase in the number of WCB trajectories with finer resolution, which also ascent higher. Moreover, the fine-resolution simulations show a new class of anticyclonic trajectories that is absent in the low-resolution simulations. This effect becomes more pronounced when convection is represented explicitly, but is not strongly affected by the treatment of cloud microphysics. We diagnose the impact of increasing resolution on WCB in terms of changes in processes like updraft velocity, diabatic heating and modification of potential vorticity by total diabatic heating and individual diabatic processes.</p>

Spatio-temporal approach for identification of critical conservation areas: a case study with two pine species from a threatened temperate forest in Mexico

2019 ◽  
Vol 28 (7) ◽  
pp. 1863-1883 ◽  
Author(s):  
Agustín Molina Sánchez ◽  
Patricia Delgado ◽  
Antonio González-Rodríguez ◽  
Clementina González ◽  
A. Francisco Gómez-Tagle Rojas ◽  
...  
Keyword(s):  
Temperate Forest ◽  
Conservation Areas ◽  
Spatio Temporal ◽  
Pine Species

scholarly journals A comparison of multiple neighborhood matrix specifications for spatio-temporal model fitting: a case study on COVID-19 data

2021 ◽  
Author(s):  
Álvaro Briz-Redón ◽  
Adina Iftimi ◽  
Juan Francisco Correcher ◽  
Jose De Andrés ◽  
Manuel Lozano ◽  
...  
Keyword(s):  
Model Fitting ◽  
Temporal Model ◽  
Spatio Temporal

scholarly journals Spatio-temporal analysis of COVID-19 incidence rate using GIS: a case study—Tehran metropolitan, Iran

GeoJournal ◽  
2021 ◽  
Author(s):  
R. Nasiri ◽  
S. Akbarpour ◽  
AR. Zali ◽  
N. Khodakarami ◽  
MH. Boochani ◽  
...  
Keyword(s):  
Incidence Rate ◽  
Temporal Analysis ◽  
Spatio Temporal

scholarly journals Multi-Criteria, Co-Evolutionary Charging Behavior: An Agent-Based Simulation of Urban Electromobility

2021 ◽  
Vol 12 (1) ◽  
pp. 18
Author(s):  
Lennart Adenaw ◽  
Markus Lienkamp
Keyword(s):  
Urban Areas ◽  
City Planning ◽  
User Behavior ◽  
Transport Sector ◽  
Simulation Framework ◽  
Agent Based Simulation ◽  
Agent Based ◽  
Charging Station ◽  
Spatio Temporal

In order to electrify the transport sector, scores of charging stations are needed to incentivize people to buy electric vehicles. In urban areas with a high charging demand and little space, decision-makers are in need of planning tools that enable them to efficiently allocate financial and organizational resources to the promotion of electromobility. As with many other city planning tasks, simulations foster successful decision-making. This article presents a novel agent-based simulation framework for urban electromobility aimed at the analysis of charging station utilization and user behavior. The approach presented here employs a novel co-evolutionary learning model for adaptive charging behavior. The simulation framework is tested and verified by means of a case study conducted in the city of Munich. The case study shows that the presented approach realistically reproduces charging behavior and spatio-temporal charger utilization.

Seabird bycatch vulnerability in pelagic longline fisheries based on modelling of a long-term dataset

2021 ◽  
pp. 1-16
Author(s):  
CAN ZHOU ◽  
NIGEL BROTHERS
Keyword(s):  
Capture Event ◽  
Retrieval Rate ◽  
Competitive Environments ◽  
Global Concern ◽  
Competitive Species ◽  
Spatio Temporal ◽  
Longline Fisheries ◽  
Pelagic Longline

Summary The incidental mortality of seabirds in fisheries remains a serious global concern. Obtaining unbiased and accurate estimates of bycatch rates is a priority for seabird bycatch mitigation and demographic research. For measuring the capture risk of seabird interactions in fisheries, the rate of carcass retrieval from hauled gear is commonly used. However, reliability can be limited by a lack of direct capture observations and the substantial pre-haul bycatch losses known to occur, meaning incidence of seabird bycatch is underestimated. To solve this problem, a new measure (bycatch vulnerability) that links an observed interaction directly to the underlying capture event is proposed to represent the capture risk of fishery interactions by seabirds. The new measure is not affected by subsequent bycatch loss. To illustrate how to estimate and analyse bycatch vulnerability, a case study based on a long-term dataset of seabird interactions and capture confirmation is provided. Bayesian modelling and hypothesis testing were conducted to identify important bycatch risk factors. Competition was found to play a central role in determining seabird bycatch vulnerability. More competitive environments were riskier for seabirds, and larger and thus more competitive species were more at risk than smaller sized and less competitive species. Species foraging behaviour also played a role. On the other hand, no additional effect of physical oceanic condition and spatio-temporal factors on bycatch vulnerability was detected. Bycatch vulnerability is recommended as a replacement for the commonly used bycatch rate or carcass retrieval rate to measure the capture risk of an interaction. Combined with a normalized contact rate, bycatch vulnerability offers an unbiased estimate of seabird bycatch rate in pelagic longline fisheries.

Texts: A Case Study of Joint Action

SATS ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Nivedita Gangopadhyay ◽  
Alois Pichler
Keyword(s):  
Social Cognition ◽  
Digital Media ◽  
Philosophy Of Mind ◽  
Joint Action ◽  
Digital Humanities ◽  
Linguistic Communication ◽  
Unique Type ◽  
Joint Actions ◽  
Spatio Temporal

Abstract Our linguistic communication often takes the form of creating texts. In this paper, we propose that creating texts or ‘texting’ is a form of joint action. We examine the nature and evolution of this joint action. We argue that creating texts ushers in a special type of joint action, which, while lacking some central features of normal, everyday joint actions such as spatio-temporal collocation of agency and embodiment, nonetheless results in an authentic, strong, and unique type of joint action agency. This special type of agency is already present in creating texts in general and is further augmented in creating texts through digital media. We propose that such a unique type of joint action agency has a transformative effect on the experience of our sense of agency and subjectivity. We conclude with the implications of the proposal for social cognition and social agency. The paper combines research in philosophy of mind with the emerging fields of digital humanities and text technology.

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