scholarly journals Intense Rainfall Events Affecting the La Plata Basin

2006 ◽  
Vol 7 (4) ◽  
pp. 769-787 ◽  
Author(s):  
Viviane B. S. Silva ◽  
Ernesto H. Berbery
Keyword(s):  
Large Scale ◽  
Amazon Basin ◽  
Level Structure ◽  
Intense Rainfall ◽  
Rainfall Events ◽  
La Plata ◽  
La Plata Basin ◽  
Intense Precipitation ◽  
Eta Model ◽  
Precipitation Events

Abstract The circulation features associated with intense precipitation events over the La Plata Basin (LPB) during the austral summers of 2001/02 and 2002/03 are investigated using the Eta Model runs generated at the University of Maryland. Based on the main mode of variability over LPB, two regions were selected: (i) the region of Brazil that is at the core of the South American summer monsoon system (SAMS) and (ii) the central region of LPB in southeastern South America (SESA). First, a comparison between the 24-h total precipitation in the Eta Model and the 24-h observed precipitation was made. Results show that the Eta Model captures well the temporal variability of precipitation events in both regions, although a positive bias is noticed over SAMS. Likewise, the model reproduces the distribution of precipitation rate over SESA, but not over SAMS. Nevertheless, the distribution of the moisture flux convergence intensity, which represents the dynamical forcing, is closer in shape to the observed precipitation distribution, suggesting that the model can be a useful tool in identifying the forcing for heavy precipitation events over both regions. Composites of atmospheric and surface variables were constructed for intense precipitation events during austral summer over both regions. Intense rainfall over the central La Plata Basin (SESA) is linked to an amplified upper-tropospheric midlatitude wave pattern in which rainfall occurs just east of an enhanced cyclonic circulation. Accompanying this circulation pattern, an enhanced low-level jet (LLJ) transports warm, moist air from the Amazon toward the region, contributing to an increase in the thermal contrast over SESA. The combined patterns of thermal and dynamical variables suggest that large-scale systems, like frontal systems, are important in producing intense rainfall events. The SAMS region events have a similar upper-level structure as in SESA, but they are longer lived. In this case, the moisture fluxes are determined by an eastward shift of the LLJ, but also directly from the Amazon Basin to the north. As expected, precipitation events produce large increases of simulated runoff. The largest impact is on the SESA region, affecting the streamflow of the Paraná, Paraguay, and Uruguay, the three main rivers of the LPB.

scholarly journals Intense precipitation events during the monsoon season in Bangladesh as captured by satellite-based products

2021 ◽  
Author(s):  
Carlo Montes ◽  
Nachiketa Acharya ◽  
S. M. Quamrul Hassan ◽  
Timothy J. Krupnik
Keyword(s):  
Monsoon Season ◽  
Well Being ◽  
Systematic Errors ◽  
Random Errors ◽  
Climate Data ◽  
Intense Rainfall ◽  
Rainfall Events ◽  
Extreme Precipitation Events ◽  
Intense Precipitation ◽  
Precipitation Events

AbstractExtreme precipitation events are a serious threat to societal well-being over rainy areas such as Bangladesh. The reliability of studies of extreme events depends on data quality and their spatial and temporal distribution, although these subjects remain knowledge gaps in many countries. This work focuses on the analysis of four satellite-based precipitation products for monitoring intense rainfall events: the Climate Hazards Group Infrared Precipitation with Station Data (CHIRPS), the PERSIANN-Climate Data Record (PERSIANN-CDR), the Integrated Multisatellite Retrievals (IMERG), and the CPC Morphing Technique (CMORPH). Five indices of intense rainfall were considered for the period 2000-2019 and a set of 31 rain gauges for evaluation. The number and amount of precipitation associated with intense rainfall events are systematically underestimated or overestimated throughout the country. While random errors are higher over the wetter and higher-elevation north- and southeastern parts of Bangladesh, biases are more homogeneous. CHIRPS, PERSIANN-CDR and IMERG perform similar capturing total seasonal rainfall, but variability is better represented by CHIRPS and IMERG. Better results were obtained by IMERG, followed by PERSIANN-CDR and CHIRPS, in terms of climatological intensity indices based on percentiles, although the three products exhibited systematic errors. IMERG and CMORPH systematically overestimate the occurrence of intense precipitation events. IMERG showed the best performance representing events over a value of 20 mm/day; CMORPH exhibited random and systematic errors strongly associated with a poor representation of interannual variability in seasonal total rainfall. The results suggest that the datasets have different potential use and such differences should be considered in future applications regarding extreme rainfall events and risk assessment in Bangladesh.

The Evolution Process of Warm Season Intense Regional Rainfall Events in Yaan

2020 ◽  
Author(s):  
Xuelin Hu
Keyword(s):  
Large Scale ◽  
Warm Season ◽  
Central China ◽  
Evolution Process ◽  
The Tibetan Plateau ◽  
Clockwise Rotation ◽  
Maximum Rainfall ◽  
Rainfall Events ◽  
Intense Precipitation ◽  
Regional Rainfall

<p>Accurate simulation and prediction of intense precipitation events require better understanding of their physical mechanisms. This study uses Yaan—a place with regional maximum rainfall in central China—to investigate the cause and process of intense precipitation. Hourly rain gauge records and the new ERA5 reanalysis are used to characterize the evolution process of warm season intense regional rainfall events (RREs) in Yaan and its associated three-dimensional circulation. Results show that before the start of the Yaan intense RREs, moderate rainfall amount (frequency) appears northeast of the key region. The rainfall then moves southward in the following several hours along the eastern periphery of the Tibetan Plateau where it reaches peak. It then moves to and end up in the south and southeast Sichuan Basin. The progression of the RREs is found to be associated with a counter-clockwise rotation of anomalous surface winds associated with a developing mesoscale surface low-pressure center, which is further associated with the southeastward progression of a large-scale synoptic scale wave. The easterly phase of the winds in the counter-clockwise rotation causes upslope motion perpendicularly toward the terrain that leads to maximum rainfall. The findings illustrate how large-scale circulations, mesoscale systems, and specific topographic features interact to create the RREs evolution in Yaan.</p>

scholarly journals Integrative taxonomy reveals disjunct distribution and first record of Hoplias misionera (Characiformes: Erythrinidae) in the Amazon River basin: morphological, DNA barcoding and cytogenetic considerations

2021 ◽  
Vol 19 (2) ◽  
Author(s):  
Karen L. A. Guimarães ◽  
Juan J. Rosso ◽  
Mendelsohn F. B. Souza ◽  
Juan M. Díaz de Astarloa ◽  
Luís R. R. Rodrigues
Keyword(s):  
Dna Barcoding ◽  
Amazon Basin ◽  
First Record ◽  
Morphological Data ◽  
Disjunct Distribution ◽  
Valid Species ◽  
Integrative Approach ◽  
Molecular Evidence ◽  
La Plata ◽  
La Plata Basin

Abstract The Hoplias malabaricus group encompasses six valid species and still is believed to harbors cryptic diversity. In this work, an integrative approach including morphological, DNA barcoding, and cytogenetic considerations was conducted to characterize a population of H. malabaricus from the Amazon basin that was recently allocated in the same mitochondrial lineage with H. misionera, a species originally described from La Plata basin. The DNA barcoding analysis revealed that the Amazon population nested together with H. misionera specimens from the La Plata basin (BIN AAB1732) in the same cluster. The intragroup distance (0.5%) was 12 times lower than the nearest neighbor (6%) distance. The morphometric analysis demonstrated slightly variation between Amazon and La Plata populations, being the former composed by larger specimens. Further morphological data supported the molecular evidence of H. misionera inhabiting Amazon basin. The karyotype characterization of H. misionera in the Amazon population showed 2n=40 and karyotypic formulae 20m+20sm, that added to C-banding, Ag-NOR and 18S results are suggestive of the similarity to karyomorph C of H. malabaricus. This work reveals the first record of H. misionera outside of La Plata basin and expands the species distribution for 2500 km northward until the Marajó Island, estuary of Amazonas River.

scholarly journals Runoff reaction from extreme rainfall events on natural hillslopes: A data set from 132 large scale sprinkling experiments in south-west Germany

2019 ◽  
Author(s):  
Fabian Ries ◽  
Lara Kirn ◽  
Markus Weiler
Keyword(s):  
Large Scale ◽  
Subsurface Flow ◽  
West Germany ◽  
Runoff Generation ◽  
Large Variability ◽  
Maximum Rainfall ◽  
Rainfall Events ◽  
Extreme Precipitation Events ◽  
South West ◽  
Precipitation Events

Abstract. Pluvial or flash floods generated by heavy precipitation events cause high economic damages and loss of life worldwide. As discharge observations from such extreme occurrences are rare especially on the scale of small catchments or even hillslopes, data from artificial sprinkling experiments offer valuable information on runoff generation processes, overland and subsurface flow rates and response times. We conducted 132 large-scale sprinkling experiments on natural hillslopes at 23 sites with different soil types and geology on pastures and arable lands within the federal state of Baden-Württemberg in south-west Germany. The experiments were realized between 2016 and 2017. Simulated rainfall events of varying durations were based on a) the site-specific 100-year return periods of rainfall with different durations and b) the maximum rainfall intensity observed locally. The 100 m2 experimental area was divided into three individual plots and overland and subsurface flow, soil moisture and water level dynamics in the temporarily saturated soil zone were measured at 1-minute resolution. Furthermore, soil characteristics were described in detail for each site. The data was carefully processed and corrected for measurement errors and combined to a consistent and easy to use database. The experiments revealed a large variability of possible runoff responses to similar rainfall characteristics. In general, agricultural fields produced more overland flow than grassland. The latter generated hardly any runoff during the first simulated 100-year event on initially dry soils. The dataset provides valuable information on runoff generation variability from natural hillslopes and may be used for the development and evaluation of hydrological models, especially those considering physical processes governing runoff generation during extreme precipitation events. The dataset presented in this paper is freely available from the FreiDok plus data repository (https://doi.org/10.6094/UNIFR/149650, Ries et al., 2019).

Mid-Tropospheric Flow Characteristics of Intense Precipitation Events in the Southeastern USA

2020 ◽  
Vol 11 (3) ◽  
pp. 10-23
Author(s):  
Walker Skeeter ◽  
Jason Senkbeil
Keyword(s):  
Large Scale ◽  
Flow Characteristics ◽  
Reanalysis Data ◽  
Southern Plains ◽  
Intense Precipitation ◽  
Precipitation Characteristics ◽  
And Cluster Analysis ◽  
Gis Methods ◽  
Manual Classification ◽  
Precipitation Events

This study evaluated 500mb and 850mb flow patterns as well as surface pressure and 72-hour precipitation characteristics of large areal scale intense precipitation events in the Southeastern United States from 1950-2016. This was attempted using a combination of statistical methods utilizing PCA and cluster analysis as well as a manual classification scheme based on synoptic-scale storm type and formation location. All large-scale events were able to fit within one of five manual classifications: tropical events, frontal events, and three mid-latitude cyclone types: those that formed over the Southeast/Gulf of Mexico, the southern plains, and the Midwest/northern plains. This research builds upon GIS methods of classifying flow characteristics utilizing reanalysis data and has the potential to aide forecasters in identifying setups conducive to large-scale intense precipitation events.

INTER-SEASONAL AND INTER-BASINS HYDROLOGICAL COUPLING IN SOUTH AMERICA

2021 ◽  
Author(s):  
Paulo Rodrigo Zanin ◽  
Prakki Satyamurty
Keyword(s):  
Soil Moisture ◽  
Amazon Basin ◽  
Winter Season ◽  
Western Region ◽  
South American ◽  
La Plata ◽  
La Plata Basin ◽  
Precipitation Recycling ◽  
Source Sink ◽  
Southeastern Region

AbstractThe inter-seasonal and inter-basins hydrological couplings between the Amazon and the La Plata basins are obtained with the help of ERA-5 atmospheric reanalysis, MERGE/CPTEC precipitation, GLEAM evapotranspiration and the GLDAS/Noah soil moisture datasets. The hypotheses formulated by Zanin and Satyamurty (2020a) about the hydrological processes interconnecting the Amazon Basin and the La Plata Basin are tested. A new method for finding the source-sink relationships among the boxes (regions) is presented. The precipitation recycling, frequency of source-sink behaviors, the soil moisture memory and the continental moisture transport between remote regions are evaluated. The main result of this study is that the amount of water precipitated over the Southeastern region of the Amazon Basin at the end of the South American Monsoon during autumn season, influences the amount of precipitation during winter season over the Central-western region of the La Plata Basin.

Response of Humidity and Clouds to Tropical Deep Convection

2009 ◽  
Vol 22 (9) ◽  
pp. 2389-2404 ◽  
Author(s):  
Mark D. Zelinka ◽  
Dennis L. Hartmann
Keyword(s):  
Large Scale ◽  
Deep Convection ◽  
Lower Troposphere ◽  
Upward Motion ◽  
Temporal Separation ◽  
Convective Event ◽  
Clear Sky ◽  
Intense Precipitation ◽  
Upper Level ◽  
Precipitation Events

Abstract Currently available satellite data can be used to track the response of clouds and humidity to intense precipitation events. A compositing technique centered in space and time on locations experiencing high rain rates is used to detail the characteristic evolution of several quantities measured from a suite of satellite instruments. Intense precipitation events in the convective tropics are preceded by an increase in low-level humidity. Optically thick cold clouds accompany the precipitation burst, which is followed by the development of spreading upper-level anvil clouds and an increase in upper-tropospheric humidity over a broader region than that occupied by the precipitation anomalies. The temporal separation between the convective event and the development of anvil clouds is about 3 h. The humidity increase at upper levels and the associated decrease in clear-sky longwave emission persist for many hours after the convective event. Large-scale vertical motions from reanalysis show a coherent evolution associated with precipitation events identified in an independent dataset: precipitation events begin with stronger upward motion anomalies in the lower troposphere, which then evolve toward stronger upward motion anomalies in the upper troposphere, in conjunction with the development of anvil clouds. Greater upper-tropospheric moistening and cloudiness are associated with larger-scale and better-organized convective systems, but even weaker, more isolated systems produce sustained upper-level humidity and clear-sky outgoing longwave radiation anomalies.

Precipitation scaling in the tropics with a convection-permitting model

2020 ◽  
Author(s):  
Daniel Argüeso ◽  
Alejandro Di Luca ◽  
Nicolas Jourdain ◽  
Romualdo Romero ◽  
Victor Homar
Keyword(s):  
Water Vapor ◽  
Large Scale ◽  
Potential Temperature ◽  
Lower Troposphere ◽  
Dew Point ◽  
Precipitation Extremes ◽  
Maritime Continent ◽  
Near Surface ◽  
Intense Precipitation ◽  
Precipitation Events

<p>The Maritime Continent is a major convective area and precipitation processes in the region pose great challenges to atmospheric models. A combination of large-scale drivers, such as the Madden-Julian Oscillation and ENSO, and fine-scale processes, such as orographically-forced precipitation, land-sea circulations and tropical convection, governs rainfall in the Maritime Continent. The use of convection-permitting models in the region has shown improved performance in the simulation of precipitation characteristics that are key for the region (i.e. diurnal cycle).</p><p>Most of the rainfall occurring over land is concentrated in the late afternoon and precipitation extremes often occur over short periods of time. The availability of water vapor in the lower troposphere and the high water-holding capacity of a warm atmosphere favors very intense precipitation events, according to the Clausius-Clapeyron relationship. In a warming climate, a full understanding of the so-called precipitation scaling with temperature is thus crucial. However, this potential generally requires the atmosphere be saturated and convection be initiated to become effective. Using a regional climate model operating at convection-permitting scales over 3 consecutive wet seasons, we investigate the response of intense precipitation to temperature.</p><p>In this presentation, we examine different approaches to relate precipitation extremes to near-surface temperature and dew-point temperature. We show that the relationship breaks at certain thresholds that are relatively uniform across islands. The region is well supplied with water vapor and the break is not explained by a deficit in water vapor, unlike previously proposed for other water-limited regions. We identify possible reasons for this behavior, such as the lack of environmental conditions that trigger convection. In this context, we explore the sensitivity of the modelling system to the convection representation (explicit vs. parameterized) and discuss the implications for future changes in intense precipitation events. Finally, we put forward the use of specific variables, such as temperature and equivalent potential temperature integrated in the vertical. These variables not only are coherent with the CC equation but also acknowledge the different warming rates near the surface and at higher tropospheric levels, where precipitating processes actually occur.</p>

Searching for resemblance between large-scale sea level pressure patterns leading to “intense” precipitation events over Italy

2008 ◽  
Vol 95 (1-2) ◽  
pp. 183-196 ◽  
Author(s):  
N. Tartaglione ◽  
M. Maugeri ◽  
F. Dalan ◽  
M. Brunetti ◽  
T. Nanni ◽  
...  
Keyword(s):  
Sea Level ◽  
Large Scale ◽  
Sea Level Pressure ◽  
Level Pressure ◽  
Intense Precipitation ◽  
Precipitation Events

scholarly journals Biomass burning CCN enhance the dynamics of a mesoscale convective system over the La Plata Basin: a numerical approach

2018 ◽  
Vol 18 (3) ◽  
pp. 2081-2096
Author(s):  
Gláuber Camponogara ◽  
Maria Assunção Faus da Silva Dias ◽  
Gustavo G. Carrió
Keyword(s):  
Biomass Burning ◽  
Amazon Basin ◽  
Cloud Condensation Nuclei ◽  
Mesoscale Convective System ◽  
Mesoscale Convective Systems ◽  
Convective System ◽  
La Plata ◽  
Convective Systems ◽  
La Plata Basin ◽  
Mesoscale Convective

Abstract. High aerosol loadings are discharged into the atmosphere every year by biomass burning in the Amazon and central Brazil during the dry season (July–December). These particles, suspended in the atmosphere, can be carried via a low-level jet toward the La Plata Basin, one of the largest hydrographic basins in the world. Once they reach this region, the aerosols can affect mesoscale convective systems (MCSs), whose frequency is higher during the spring and summer over the basin. The present study is one of the first that seeks to understand the microphysical effects of biomass burning aerosols from the Amazon Basin on mesoscale convective systems over the La Plata Basin. We performed numerical simulations initialized with idealized cloud condensation nuclei (CCN) profiles for an MCS case observed over the La Plata Basin on 21 September 2010. The experiments reveal an important link between CCN number concentration and MCS dynamics, where stronger downdrafts were observed under higher amounts of aerosols, generating more updraft cells in response. Moreover, the simulations show higher amounts of precipitation as the CCN concentration increases. Despite the model's uncertainties and limitations, these results represent an important step toward the understanding of possible impacts on the Amazon biomass burning aerosols over neighboring regions such as the La Plata Basin.

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