Mesoscale Convective Systems Monitoring on the Basis of MSG Data – Case Studies

Abstract Analysis described in the paper were made in the frame of the PROZA (Operational decisionmaking based on atmospheric conditions, http://projekt-proza.pl/) project co-financed by the European Union through the European Regional Development Fund. One of its tasks was to develop an operational forecast system, which is going to support different economies branches like forestry or fruit farming by reducing the risk of economic decisions with taking into consideration weather conditions. The main purpose of the paper is to describe the method of the MCSs (Mesoscale Convective Systems) tracking on the basis of the MSG (Meteosat Second Generation) data. Until now several tests were performed. The Meteosat satellite images in selected spectral channels collected for Central Europe Region for May 2010 were used to detect and track cloud systems recognized as MCSs in Poland. The ISIS tracking method was applied here. First the cloud objects are defined using the temperature threshold and next the selected cells are tracked using principle of overlapping position on consecutive images. The main benefit of using a temperature threshold to define cells is its efficiency. During the tracking process the algorithm links the cells of the image at time t to the one of the following image at time t+dt that correspond to the same cloud system. Selected cases present phenomena, which appeared at the territory of Poland. They were compared to the weather radar data and UKMO UM (United Kingdom MetOffice Unified Model) forecasts. The paper presents analysis of exemplary MCSs in the context of near realtime prediction system development and proves that developed tool can be helpful in MCSs monitoring.

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Lightning and precipitation produced by severe weather systems over Belém, Brazil

Revista Brasileira de Meteorologia ◽

10.1590/0102-778620130039 ◽

2014 ◽

Vol 29 (spe) ◽

pp. 41-59 ◽

Cited By ~ 3

Author(s):

Wanda Maria do Nascimento Ribeiro ◽

José Ricardo Santos Souza ◽

Márcio Nirlando Gomes Lopes ◽

Renata Kelen Cardoso Câmara ◽

Edson José Paulino Rocha ◽

...

Keyword(s):

Large Scale ◽

Electric Activity ◽

Weather Conditions ◽

Rain Gauge ◽

Mesoscale Convective Systems ◽

Major Influence ◽

Rainfall Events ◽

Convective Systems ◽

Mesoscale Convective ◽

Cg Lightning

CG Lightning flashes events monitored by a LDN of the Amazon Protection System, which included 12 LPATS IV VAISALA sensors distributed over eastern Amazonia, were analyzed during four severe rainstorm occurrences in Belem-PA-Brazil, in the 2006-2007 period. These selected case studies referred to rainfall events, which produced more than 25 mm/hour, or more than 40 mm/ 2 hours of precipitation rate totals, registered by a tipping bucket automatic high-resolution rain gauge, located at 1º 47' 53" S and 48º 30' 16" W. Centered at this location, a 30 ,10 and 5 km radius circles were drawn by means of a geographic information system, and the data from lightning occurrences within this larger area, were set apart for analysis. During these severe storms the CG lightning events, occurred almost randomly over the surrounding defined circle, previously covered by mesoscale convective systems, for all cases studied. This work also showed that the interaction between large-scale and mesoscale weather conditions have a major influence on the intensity of the storms studied cases. In addition to the enhancement of the lightning and precipitation rates, the electric activity within the larger circles can precede the rainfall at central point of the areas

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Mesoscale convective systems as a source of electromagnetic signals registered by ground-based system and DEMETER (Detection of Electro-Magnetic Emissions Transmitted from Earthquake Regions) satellite

Annales Geophysicae ◽

10.5194/angeo-39-321-2021 ◽

2021 ◽

Vol 39 (2) ◽

pp. 321-326

Author(s):

Karol Martynski ◽

Jan Blecki ◽

Roman Wronowski ◽

Andrzej Kulak ◽

Janusz Mlynarczyk ◽

...

Keyword(s):

Low Frequency ◽

Field Measurements ◽

Mesoscale Convective Systems ◽

Atmospheric Conditions ◽

Very High Frequency ◽

Convective Systems ◽

Mesoscale Convective ◽

Electromagnetic Signals ◽

Electro Magnetic ◽

Atmospheric Discharges

Abstract. Mesoscale convective systems (MCSs) are especially visible in the summertime when there is an advection of warm maritime air from the west. Advection of air masses is enriched by water vapour, the source of which can be found over the Mediterranean Sea. In propitious atmospheric conditions, and thus significant convection, atmospheric instability or strong vertical thermal gradient leads to the development of strong thunderstorm systems. In this paper, we discuss one case of MCSs, which generated a significant amount of +CG (cloud-to-ground), −CG and intracloud (IC) discharges. We have focused on the ELF (extremely low frequency; < 1 kHz) electromagnetic field measurements, since they allow us to compute the charge moments of atmospheric discharges. Identification of the MCSs is a complex process, due to many variables which have to be taken into account. For our research, we took into consideration a few tools, such as cloud reflectivity, atmospheric soundings and data provided by PERUN (Polish system of the discharge localisation system), which operates in a very high frequency (VHF) range (113.5–114.5 MHz). Combining the above-described measurement systems and tools, we identified a MCS which occurred in Poland on 23 July 2009. Furthermore, it fulfilled our requirements since the thunderstorm crossed the path of the DEMETER (Detection of Electro-Magnetic Emissions Transmitted from Earthquake Regions) overpass.

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Tropical Atlantic Hurricanes, Easterly Waves, and West African Mesoscale Convective Systems

Advances in Meteorology ◽

10.1155/2010/284503 ◽

2010 ◽

Vol 2010 ◽

pp. 1-13 ◽

Cited By ~ 6

Author(s):

Yves K. Kouadio ◽

Luiz A. T. Machado ◽

Jacques Servain

Keyword(s):

West Africa ◽

West African ◽

Mesoscale Convective Systems ◽

Tropical Atlantic ◽

Atmospheric Conditions ◽

Easterly Waves ◽

Convective Systems ◽

Mesoscale Convective ◽

Sst Anomaly ◽

Atlantic Hurricanes

The relationship between tropical Atlantic hurricanes (Hs), atmospheric easterly waves (AEWs), and West African mesoscale convective systems (MCSs) is investigated. It points out atmospheric conditions over West Africa before hurricane formation. The analysis was performed for two periods, June–November in 2004 and 2005, during which 12 hurricanes (seven in 2004, five in 2005) were selected. Using the AEW signature in the 700 hPa vorticity, a backward trajectory was performed to the African coast, starting from the date and position of each hurricane, when and where it was catalogued as a tropical depression. At this step, using the Meteosat-7 satellite dataset, we selected all the MCSs around this time and region, and tracked them from their initiation until their dissipation. This procedure allowed us to relate each of the selected Hs with AEWs and a succession of MCSs that occurred a few times over West Africa before initiation of the hurricane. Finally, a dipole in sea surface temperature (SST) was observed with a positive SST anomaly within the region of H generation and a negative SST anomaly within the Gulf of Guinea. This SST anomaly dipole could contribute to enhance the continental convergence associated with the monsoon that impacts on the West African MCSs formation.

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Mesoscale Convective Systems as a source of electromagnetic signals registered by ground-based system and DEMETER satellite

10.5194/angeo-2020-64 ◽

2020 ◽

Author(s):

Karol Martynski ◽

Jan Blecki ◽

Roman Wronowski ◽

Andrzej Kulak ◽

Janusz Mlynarczyk ◽

...

Keyword(s):

Mesoscale Convective Systems ◽

Atmospheric Conditions ◽

The West ◽

Low Frequencies ◽

Air Masses ◽

Convective Systems ◽

Demeter Satellite ◽

Mesoscale Convective ◽

Electromagnetic Signals ◽

Maritime Air

Abstract. Mesoscale Convective Systems (MCS) are especially visible in the summertime, when there is an advection of warm maritime air from the West. Advection of air masses is enriched by water vapour, which source can be found over the Mediterranean Sea. In propitious atmospheric conditions, thus significant convection, atmospheric instability or strong vertical thermal gradient, lead to the development of strong thunderstorm systems. In this paper we discuss one case of MCS, which generated a significant amount of +CG, -CG and IC discharges. We have focused on the ELF (Extremely Low Frequencies,

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Analysis of Strengthening and Dissipating Mesoscale Convective Systems Propagating off the West African Coast

Monthly Weather Review ◽

10.1175/mwr-d-13-00388.1 ◽

2014 ◽

Vol 142 (12) ◽

pp. 4600-4623 ◽

Cited By ~ 6

Author(s):

Abdou L. Dieng ◽

Laurence Eymard ◽

Saidou M. Sall ◽

Alban Lazar ◽

Marion Leduc-Leballeur

Keyword(s):

Radar Data ◽

West African ◽

Mesoscale Convective Systems ◽

The West ◽

Convective Systems ◽

Wave Trough ◽

West African Coast ◽

African Coast ◽

Mesoscale Convective ◽

Tropical Depressions

Abstract A large number of Atlantic tropical depressions are generated in the eastern basin in relation to the African easterly wave (AEW) and embedded mesoscale convective systems (MCSs) coming from the African continent. In this paper, the structures of strengthening and dissipating MCSs evolving near the West African coast are analyzed, including the role of the ocean surface conditions in their evolution. Satellite infrared brightness temperature and meteorological radar data over seven summer seasons between 1993 and 2006 are used to subjectively select 20 cases of strengthening and dissipating MCSs in the vicinity of the Senegal coast. With these observed MCSs, a lagged composite analysis is then performed using Interim ECMWF Re-Analysis (ERA-Interim) and Climate Forecast System Reanalysis (CFSR). It is shown that the strengthening MCS is generally preceded by prior passage of an AEW near the West African coast. This previous wave trough is associated with a convective cyclonic circulation in the low and middle troposphere, which enhances the southwesterly flow and then provides humidity to the strengthening MCS, located in the vicinity of the subsequent AEW trough. This is favored by the contraction of the wavelength associated with the two troughs. The sea surface contributes to the MCS enhancement through surface evaporation flux. But this contribution is found to be less important than advection of humidity from the previous wave trough. These conditions are almost not found in the dissipating MCS cases, which dissipate in a dry environment dominated by a subsident and anticyclonic circulation, with generally no interaction with a previous wave trough.

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Modeling the Flash Rate of Thunderstorms. Part I: Framework

Monthly Weather Review ◽

10.1175/mwr-d-10-05031.1 ◽

2011 ◽

Vol 139 (10) ◽

pp. 3093-3111 ◽

Cited By ~ 15

Author(s):

Johannes M. L. Dahl ◽

Hartmut Höller ◽

Ulrich Schumann

Keyword(s):

Radar Data ◽

Mesoscale Convective Systems ◽

New Approach ◽

Flash Rate ◽

Convective Systems ◽

Cloud Properties ◽

Lightning Detection ◽

Mesoscale Convective ◽

Lightning Discharges ◽

New Framework

Abstract In this study a straightforward theoretical approach to determining the flash rate in thunderstorms is presented. A two-plate capacitor represents the basic dipole charge structure of a thunderstorm, which is charged by the generator current and discharged by lightning. If the geometry of the capacitor plates, the generator-current density, and the lightning charge are known, and if charging and discharging are in equilibrium, then the flash rate is uniquely determined. To diagnose the flash rate of real-world thunderstorms using this framework, estimates of the required relationships between the predictor variables and observable cloud properties are provided. With these estimates, the flash rate can be parameterized. In previous approaches, the lightning rate has been set linearly proportional to the electrification rate (such as the storm’s generator power or generator current), which implies a constant amount of neutralization by lightning discharges (such as lightning energy or lightning charge). This leads to inconsistencies between these approaches. Within the new framework proposed here, the discharge strength is allowed to vary with storm geometry, which remedies the physical inconsistencies of the previous approaches. The new parameterization is compared with observations using polarimetric radar data and measurements from the lightning detection network, LINET. The flash rates of a broad spectrum of discrete thunderstorm cells are accurately diagnosed by the new approach, while the flash rates of mesoscale convective systems are overestimated.

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Radar data assimilation for the simulation of mesoscale convective systems

Advances in Atmospheric Sciences ◽

10.1007/s00376-010-9162-8 ◽

2010 ◽

Vol 27 (5) ◽

pp. 1025-1042 ◽

Cited By ~ 10

Author(s):

Jo-Han Lee ◽

Hyun-Ha Lee ◽

Yonghan Choi ◽

Hyung-Woo Kim ◽

Dong-Kyou Lee

Keyword(s):

Data Assimilation ◽

Radar Data ◽

Mesoscale Convective Systems ◽

Convective Systems ◽

Mesoscale Convective ◽

Radar Data Assimilation

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Statistical Analysis of the Mesoscale Convective Systems Propagation East of the Rocky Mountains

10.21203/rs.3.rs-563940/v1 ◽

2021 ◽

Author(s):

Yunsung Hwang ◽

Yanping Li

Keyword(s):

Rocky Mountains ◽

Multiple Scales ◽

Stage Iv ◽

Radar Data ◽

Mesoscale Convective Systems ◽

Observation Data ◽

Regional Variability ◽

Time Step ◽

Convective Systems ◽

Mesoscale Convective

Abstract In this work, we characterized the occurrences and propagation speeds of Mesoscale Convective Systems (MCSs) east of the Rocky Mountains, using 15 years of radar data. The central United States has a complex topography. The region also has atmospheric environments that initiate and maintain MCSs at multiple scales. The diurnal and regional variability of MCSs based on their longevities was obtained using high-resolution observation data (Stage IV) and an object tracking algorithm MODE-Time Domain (MTD). MTD-determined MCSs in spring and summer were divided into daytime (initiated from 12 to 23 UTC, MCS12) and nighttime MCSs (formed between 00 and 11 UTC, MCS00) and into short lived (less than the 75th percentile) and long lived MCSs (greater or equal to the 75th percentile). Propagation speeds of MCSs were calculated using distances between MCSs’ centroids at each time step. We suggest a novel way to obtain a Hovmoller diagram to indicate average propagation speeds. There were two key results: 1) Spatial and temporal features of propagation speeds vary at each location and time and, 2.) heavy rainfall (rain rates ≥ 5.0 mmhr-1 ) contributed more than lighter rainfall to overall precipitation. In the east during spring, long-lived MCSs occurred more frequently in the spring than in summer. Short-lived daytime MCSs in spring and summer exhibited similar spatial distributions. In summer alone, short-lived nighttime MCSs occurred more frequently that they did in spring. To the east, the average propagation speeds of short-lived MCSs increased in spring and summer, whereas long-lived MCSs indicated decreasing trends.

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