scholarly journals The Structure and the Role of a Subsynoptic-Scale Cold Vortex on the Heavy Precipitation

1982 ◽  
Vol 60 (1) ◽  
pp. 339-354 ◽  
Author(s):  
S. Matsumoto ◽  
K. Ninomiya ◽  
R. Hasegawa ◽  
Y. Miki
Keyword(s):  
Heavy Precipitation ◽  
Cold Vortex

scholarly journals Large-scale heavy precipitation over central Europe and the role of atmospheric cyclone track types

2017 ◽  
Vol 38 ◽  
pp. e497-e517 ◽  
Author(s):  
Michael Hofstätter ◽  
Annemarie Lexer ◽  
Markus Homann ◽  
Günter Blöschl
Keyword(s):  
Central Europe ◽  
Large Scale ◽  
Heavy Precipitation ◽  
Cyclone Track

scholarly journals Parameter Modulation of Madden-Julian Oscillation Behaviors in BCC_CSM1.2: The Key Role of Moisture-Shallow Convection Feedback

Atmosphere ◽  
2019 ◽  
Vol 10 (5) ◽  
pp. 241 ◽  
Author(s):  
Kai Huang ◽  
Hong-Li Ren ◽  
Xiangwen Liu ◽  
Pengfei Ren ◽  
Yuntao Wei ◽  
...  
Keyword(s):  
Lower Troposphere ◽  
Latin Hypercube Sampling ◽  
Heavy Precipitation ◽  
Convective Precipitation ◽  
Physical Parameters ◽  
Madden Julian Oscillation ◽  
Shallow Convection ◽  
Climate System Model ◽  
New Strategy

To reveal key parameter-related physical mechanisms in simulating Madden-Julian Oscillation (MJO), seven physical parameters in the convection and cloud parameterization schemes of Beijing Climate Center Climate System Model (BCC_CSM1.2) are perturbed with Latin hypercube sampling method. A new strategy is proposed to select runs with good and poor MJO simulations among 85 generated ones. Outputs and parameter values from good and poor simulations are composited separately for comparison. Among the seven chosen parameters, a decreased value of precipitation efficiency for shallow convection, higher values of relative humidity threshold for low stable clouds and evaporation efficiency for deep convective precipitation are crucial to simulate a better MJO. Changes of the three parameters act together to suppress heavy precipitation and increase the frequency of light rainfall over the Indo-Pacific region, supplying more moisture in low and middle troposphere. As a result of a wetter lower troposphere ahead of the MJO main convection, the low-level moisture preconditioning along with the leading shallow convection tends to be enhanced, favorable for MJO’s further development and eastward propagation. The MJO’s further propagation across the Maritime Continent (MC) in good simulations is accompanied with more land precipitation dominated by shallow convection. Therefore, the above-mentioned three parameters are found to be crucial parameters out of the seven ones for MJO simulation, providing an inspiration for better MJO simulation and prediction with this model. This work is valuable as it highlights the key role of moisture-shallow convection feedback in the MJO dynamics.

scholarly journals The role of precipitation for high-magnitude flood generation in a large mountainous catchment (upper Rhône River, NW European Alps)

2019 ◽  
Author(s):  
Florian Raymond ◽  
Bruno Wilhelm ◽  
Sandrine Anquetin
Keyword(s):  
Heavy Precipitation ◽  
European Alps ◽  
Flood Events ◽  
Rhône River ◽  
High Magnitude ◽  
Extreme Flood ◽  
Rhone River ◽  
Flood Generation ◽  
Rain Floods

Abstract. High-impact climate events such as floods are highly destructive natural hazards causing widespread impacts on socio-ecosystems. However, processes leading to such events are still poorly understood, which limiting reliable prediction. This study takes advantage of centennial-long discharge series (1923–2010) and meteorological reanalysis (ERA-20C) to study processes generating the high-magnitude flood events (i.e. above the percentile 99.9) of the upper Rhône River (NW European Alps). A particular focus is paid to the role of precipitation on the flood generation to explore in what extent such events could be explained by only atmospheric variables. A flood typology is thus established using a hierarchical clustering analysis and three variables: long (8-day) and short (2-day) precipitation accumulations as well as an index characterizing the amplitude of the discharge increase during the 7 days prior to the flood day. The typology result in four classes, of which two are directly linked to precipitation. One results from heavy precipitation over two days (similar to short-rain floods in the literature) and the other one from a combination of short and long intense precipitation sequences (similar to long-rain floods). The two other types of floods cannot be explained by precipitation only, most probably involving ice and snow melting. The four events of highest magnitude (> 20 year return period) are of various types but are all triggered by heavy precipitation during the days preceding the floods. The role of the precipitation accumulations progressively decreases when considering floods of weaker magnitude, suggesting a higher diversity of processes involved in the generation of e.g. annual flooding. Our results highlight the needs to better understand the atmospheric processes leading to heavy precipitation accumulation since this would allow a better understanding of past and future trends of extreme flood events.

scholarly journals The role of climatic factors in evolving flood patterns in a Mediterranean Region (1301–2012)

2014 ◽  
Vol 11 (8) ◽  
pp. 9145-9182 ◽  
Author(s):  
A. Barrera-Escoda ◽  
M. C. Llasat
Keyword(s):  
Solar Activity ◽  
Mediterranean Region ◽  
General Circulation ◽  
Climatic Factors ◽  
Late Summer ◽  
Heavy Precipitation ◽  
Significant Rise ◽  
Flood Frequency ◽  
Quasi Biennial Oscillation

Abstract. Data on flood occurrence and flood impacts for the last seven centuries in the northeast Iberian Peninsula have been analysed in order to characterise long-term trends, anomalous periods and their relationship with different climatic factors such as precipitation, general circulation and solar activity. Catastrophic floods do not present a statistically significant trend, whereas extraordinary floods have seen a significant rise, especially from 1850 on, and were responsible for the total increase in flooding in the region. This rise can be mainly attributed to small coastal catchments, which have experienced a marked increase in developed land and population, resulting in changes in land use and greater vulnerability. Changes in precipitation alone cannot explain the variation in flood patterns, although a certain increase was shown in late summer–early autumn, when extraordinary floods are most frequently recorded. The relationship between North Atlantic circulation and floods is not as strong, due to the important role of mesoscale factors in heavy precipitation in the northwest of the Mediterranean region. However it can explain the variance to some extent, mainly in relation to the catastrophic floods experienced during the autumn. Solar activity has some impact on changes in catastrophic floods with cycles related to the Quasi-Biennial Oscillation and the Gleissberg solar cycle. In addition, anomalous periods of high flood frequency in autumn generally occurred during periods of increased solar activity. The physical influence of the latter in general circulation patterns, the high troposphere and the stratosphere, has been analysed in order to ascertain its role in causing floods.

scholarly journals Classification of Synoptic Conditions of Summer Floods in Polish Sudeten Mountains

Water ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1450
Author(s):  
Ewa Bednorz ◽  
Dariusz Wrzesiński ◽  
Arkadiusz M. Tomczyk ◽  
Dominika Jasik
Keyword(s):  
Precipitable Water ◽  
Heavy Precipitation ◽  
Mountain Areas ◽  
Sea Level Pressure ◽  
Circulation Patterns ◽  
Synoptic Conditions ◽  
High Runoff ◽  
Precipitation Enhancement

Atmospheric processes leading to extreme floods in the Polish Sudeten Mountains were described in this study. A direct impact of heavy precipitation on extremely high runoff episodes was confirmed, and an essential role of synoptic conditions in triggering abundant rainfall was proved. Synoptic conditions preceding each flood event were taken into consideration and the evolution of the pressure field as well as the moisture transport was investigated using the anomaly-based method. Maps of anomalies, constructed for the days prior to floods, enabled recognizing an early formation of negative centers of sea level pressure and also allowed distinguishing areas of positive departures of precipitable water content over Europe. Five cyclonic circulation patterns of different origin, and various extent and intensity, responsible for heavy, flood-triggering precipitation in the Sudetes, were assigned. Most rain-bringing cyclones form over the Mediterranean Sea and some of them over the Atlantic Ocean. A meridional southern transport of moisture was identified in most of the analyzed cases of floods. Recognizing the specific meteorological mechanisms of precipitation enhancement, involving evolution of pressure patterns, change in atmospheric moisture and occurrence of precipitation may contribute to a better understanding of the atmospheric forcing of floods in mountain areas and to improve predicting thereof.

SOKUR K., PALAMARCHUK L. CONDITIONS FOR THE FORMATION OF SURFACE RUNOFF, WHICH IS FORMED AS A RESULT OF HEAVY AND DANGEROUS PRECIPITATION WITHIN URBANIZED AREAS

2021 ◽  
pp. 36-49
Author(s):  
K. Sokur ◽  
L. Palamarchuk
Keyword(s):  
Surface Runoff ◽  
Atmospheric Precipitation ◽  
Heavy Precipitation ◽  
Underlying Surface ◽  
National Regulation ◽  
Convective Clouds ◽  
Stratus Clouds ◽  
Formation Conditions ◽  
Physical Features

The research investigates atmospheric precipitation, which according to Ukrainian national regulation has reached the criteria of heavy (≥ 50 mm at ≤ 12 hours) and dangerous (15 – 49 mm at ≤ 12 hours). A total of 98 cases of heavy precipitation (2005 – 2018), and 14 cases of dangerous precipitation (2017 – 2018) were analyzed. The research focuses on the formation conditions and volumes of surface runoff that forms on various types of underlying surface. To obtain a statistically valid classification, a cluster analysis of heavy and dangerous precipitation was carried out. The analysis allowed to distinguish three blocks or clusters, one of which corresponds to the type “mix” of heavy and slight precipitations during the development of frontal stratus clouds with so-called “submerged or flooded” convection, the second cluster corresponds to the type “heavy precipitations”, the third cluster is similar to the first cluster, but is marked by a decrease in the intensity of processes. The degree of connection between the intensity of heavy precipitation and the height of the clouds top was investigated. As a result, it was found that there is an inverse relation between the values. The physical features of the processes of cloud and precipitation formation was considered. The exceptional role of convective clouds in individual frontal massifs and also in the form of “submerged or flooded convection” in the massifs of stratus clouds in the formation of significant volumes of rainwater on the underlying surface was noted. The structure of the temporal changes in precipitation intensity was established: the maximum intensity values, the time of their occurrence, the availability and number of amplification waves and their temporal parameters. On the basis of the obtained indicators, the quantity of the surface runoff for determined processes and for amplification periods were calculated. As a result, it was found that the surface runoff, which formed in the built-up areas, exceeds the surface runoff from the moderately built-up area with almost no artificial pavement by 100 – 300 %.

Heavy Precipitation Systems in the Mediterranean Area: The Role of GPM

2020 ◽  
pp. 819-841
Author(s):  
Giulia Panegrossi ◽  
Anna Cinzia Marra ◽  
Paolo Sanò ◽  
Luca Baldini ◽  
Daniele Casella ◽  
...  
Keyword(s):  
Heavy Precipitation ◽  
Mediterranean Area ◽  
The Mediterranean
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