Analysis of Determinants for an Enhanced and Long-lasting Coastal Convective System by Means of a Case Study (26 July 2011)

2019 ◽  
Vol 36 (12) ◽  
pp. 1327-1339 ◽  
Author(s):  
Jung-Tae Lee ◽  
Dong-In Lee ◽  
Shingo Shimizu ◽  
Cheol-Hwan You
Keyword(s):  
Convective System

Predecessor Rain Events ahead of Tropical Cyclones

2010 ◽  
Vol 138 (8) ◽  
pp. 3272-3297 ◽  
Author(s):  
Thomas J. Galarneau ◽  
Lance F. Bosart ◽  
Russ S. Schumacher
Keyword(s):  
Tropical Cyclones ◽  
Heavy Rainfall ◽  
The United States ◽  
Synoptic Climatology ◽  
Convective System ◽  
Low Level ◽  
Rain Events ◽  
Tropical Moisture ◽  
Baroclinic Zone

Abstract Twenty-eight predecessor rain events (PREs) that occurred over the United States east of the Rockies during 1995–2008 are examined from a synoptic climatology and case study perspective. PREs are coherent mesoscale regions of heavy rainfall, with rainfall rates ≥100 mm (24 h)−1, that can occur approximately 1000 km poleward of recurving tropical cyclones (TCs). PREs occur most commonly in August and September, and approximately 36 h prior to the arrival of the main rain shield associated with the TC. A distinguishing feature of PREs is that they are sustained by deep tropical moisture that is transported poleward directly from the TC. PREs are high-impact weather events that can often result in significant inland flooding, either from the PRE itself or from the subsequent arrival of the main rain shield associated with the TC that falls onto soils already saturated by the PRE. The composite analysis shows that on the synoptic-scale, PREs form in the equatorward jet-entrance region of a 200-hPa jet on the western flank of a 925-hPa equivalent potential temperature ridge located east of a 700-hPa trough. On the mesoscale, PREs occur in conjunction with low-level frontogenetical forcing along a baroclinic zone where heavy rainfall is focused. A case study analysis was conducted of a PRE ahead of TC Erin (2007) that produced record-breaking rainfall (>250 mm) from southern Minnesota to Lake Michigan. This analysis highlighted the importance of frontogenetical forcing along a low-level baroclinic zone in the presence of deep tropical moisture from TC Erin in producing a long-lived, quasi-stationary mesoscale convective system.

Case Study of a Severe Mesoscale Convective System in Central Arizona

1995 ◽  
Vol 10 (3) ◽  
pp. 643-665 ◽  
Author(s):  
Darren M. McCollum ◽  
Robert A. Maddox ◽  
Kenneth W. Howard
Keyword(s):  
Mesoscale Convective System ◽  
Convective System ◽  
Mesoscale Convective ◽  
Central Arizona

Initialization of a fine-scale model for convective-system prediction: A case study

2000 ◽  
Vol 126 (570) ◽  
pp. 3041-3065 ◽  
Author(s):  
Véronique Ducrocq ◽  
Jean-Philippe Lapore ◽  
Jean-Luc Redelsperger ◽  
Françoise Orain
Keyword(s):  
Scale Model ◽  
Convective System ◽  
Fine Scale

scholarly journals Estimating the NO<sub>x</sub> produced by lightning from GOME and NLDN data: a case study in the Gulf of Mexico

2006 ◽  
Vol 6 (4) ◽  
pp. 1075-1089 ◽  
Author(s):  
S. Beirle ◽  
N. Spichtinger ◽  
A. Stohl ◽  
K. L. Cummins ◽  
T. Turner ◽  
...  
Keyword(s):  
Nitrogen Oxides ◽  
Gulf Of Mexico ◽  
Global Scale ◽  
Tropospheric Chemistry ◽  
Ozone Production ◽  
Convective System ◽  
Strong Impact ◽  
Lightning Detection ◽  
Order Of Magnitude

Abstract. Nitrogen oxides (NOxNO+NO2) play an important role in tropospheric chemistry, in particular in catalytic ozone production. Lightning provides a natural source of nitrogen oxides, dominating the production in the tropical upper troposphere, with strong impact on tropospheric ozone and the atmosphere's oxidizing capacity. Recent estimates of lightning produced NOx (LNOx) are of the order of 5 Tg [N] per year with still high uncertainties in the range of one order of magnitude. The Global Ozone Monitoring Experiment (GOME) on board the ESA-satellite ERS-2 allows the retrieval of tropospheric column densities of NO2 on a global scale. Here we present the GOME NO2 measurement directly over a large convective system over the Gulf of Mexico. Simultaneously, cloud-to-ground (CG) flashes are counted by the U.S. National Lightning Detection Network (NLDNTM), and extrapolated to include intra-cloud (IC)+CG flashes based on a climatological IC:CG ratio derived from NASA's space-based lightning sensors. A series of 14 GOME pixels shows largely enhanced column densities over thick and high clouds, coinciding with strong lightning activity. The enhancements can not be explained by transport of anthropogenic NOx and must be due to fresh production of LNOx. A quantitative analysis, accounting in particular for the visibility of LNOx from satellite, yields a LNOx production of 90 (32-240) moles of NOx, or 1.3 (0.4-3.4) kg [N], per flash. If simply extrapolated, this corresponds to a global LNOx production of 1.7 (0.6-4.7)Tg [N]/yr.

scholarly journals Dual-Doppler radar analysis of a near-shore line-shaped convective system on 27 July 2011, Korea: a case study

2014 ◽  
Vol 66 (1) ◽  
pp. 23453 ◽  
Author(s):  
Jung-Tae Lee ◽  
Dong-In Lee ◽  
Cheol-Hwan You ◽  
Hiroshi Uyeda ◽  
Yu-Chieng Liou ◽  
...  
Keyword(s):  
Doppler Radar ◽  
Convective System ◽  
Shore Line ◽  
Near Shore ◽  
Dual Doppler Radar

scholarly journals Cloud-scale modelling of the impact of deep convection on the fate of oceanic bromoform in the troposphere: a case study over the west coast of Borneo

2020 ◽  
Author(s):  
Paul D. Hamer ◽  
Virginie Marécal ◽  
Ryan Hossaini ◽  
Michel Pirre ◽  
Gisèle Krysztofiak ◽  
...  
Keyword(s):  
Boundary Layer ◽  
West Coast ◽  
Deep Convection ◽  
Convective System ◽  
The West ◽  
Upper Troposphere ◽  
Convective Systems ◽  
Mixing Ratios ◽  
The Impact

Abstract. Coastal oceans emit bromoform (CHBr3) that can be transported rapidly to the upper troposphere by deep convection. In the troposphere, the spatial and vertical distribution of CHBr3 and its product gases (PGs) depend on emissions, chemical processing, transport by large scale flow, convection, and associated washout. This paper presents a modelling study on the fate of CHBr3 and its PGs in the troposphere. A case study at cloud scale was conducted along the west coast of Borneo, when several deep convective systems triggered in the afternoon and early evening of November 19th 2011. These systems were sampled by the Falcon aircraft during the field campaign of the SHIVA project. We analyse these systems using a simulation with the cloud-resolving meteorological model C-CATT-BRAMS at 2 × 2 km resolution that describes transport, photochemistry, and washout of CHBr3. We find that simulated CHBr3 mixing ratios and the observed values in the boundary layer and the outflow of the convective systems agree. However, the model underestimates the background CHBr3 mixing ratios in the upper troposphere, which suggests a missing source. An analysis of the simulated chemical speciation of bromine within and around each simulated convective system during the mature convective stage reveals that > 85 % of the bromine derived from CHBr3 and its PGs is transported vertically to the point of convective detrainment in the form of CHBr3 and that the remaining small fraction is in the form of organic PGs, principally insoluble brominated carbonyls produced from the photo-oxidation of CHBr3. The model simulates that within the boundary layer and free troposphere, the inorganic PGs are only present in soluble forms, i.e., HBr, HOBr, and BrONO2, and consequently, within the convective clouds, the inorganic PGs are almost entirely removed by wet scavenging. For the conditions of the simulated case study Br2 plays no significant role in the vertical transport of bromine. This likely results from the small simulated quantities of inorganic bromine involved, the presence of HBr in large excess compared to HOBr and the less soluble BrO, and the relatively quick removal of soluble compounds within the convective column. This prevalence of HBr is a result of the wider simulated regional atmospheric composition whereby background tropospheric ozone levels are exceptionally low.

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