scholarly journals Impacts of a Groundwater Scheme on Hydroclimatological Conditions over Southern South America

2016 ◽  
Vol 17 (11) ◽  
pp. 2959-2978 ◽  
Author(s):  
J. Alejandro Martinez ◽  
Francina Dominguez ◽  
Gonzalo Miguez-Macho
Keyword(s):  
South America ◽  
Rainy Season ◽  
Root Zone ◽  
Sensitivity Study ◽  
Near Surface ◽  
Southern South America ◽  
La Plata ◽  
La Plata Basin ◽  
Simulated Precipitation ◽  
The Impact

Abstract A sensitivity study of the impact of a groundwater scheme on hydrometeorological variables in coupled land–atmosphere simulations over southern South America is presented. It is found that shallow water tables in the groundwater scheme lead to reduced drainage and even upward capillary fluxes over parts of the central and southern La Plata basin. This leads to an increase in the simulated moisture in the root zone, which in turn produces an increase in evapotranspiration (ET) over the southern part of the domain, where ET is water limited. There is also a decrease in the near-surface temperature, in the range 0.5°–1.0°C. During the dry season, the increases in ET and relative humidity over the central La Plata coincide with an increase in precipitation downstream. Including groundwater leads to an increase in precipitation over parts of the central and southern La Plata basin during the early rainy season (October–December). The overall increase in ET and precipitation over the southern La Plata basin during the early rainy season is 13% and 10%, respectively. The additional precipitation comes from both an increase in the availability of atmospheric moisture when the groundwater scheme is used and its effect on the atmospheric instability. In the La Plata basin, including a representation of groundwater increases simulated precipitation and partially alleviates a warm and dry bias present in simulations without realistic subsurface hydrology.

scholarly journals Effects of a Groundwater Scheme on the Simulation of Soil Moisture and Evapotranspiration over Southern South America

2016 ◽  
Vol 17 (11) ◽  
pp. 2941-2957 ◽  
Author(s):  
J. Alejandro Martinez ◽  
Francina Dominguez ◽  
Gonzalo Miguez-Macho
Keyword(s):  
South America ◽  
Land Surface ◽  
Climate Model ◽  
Soil Column ◽  
Water Storage ◽  
Surface Model ◽  
Southern South America ◽  
La Plata ◽  
Continental Scale ◽  
La Plata Basin

Abstract The effects of groundwater dynamics on the representation of water storage and evapotranspiration (ET) over southern South America are studied from simulations with the Noah-MP land surface model. The model is run with three different configurations: one including the Miguez-Macho and Fan groundwater scheme, another with the Simple Groundwater Model (SIMGM), and the other with free drainage at the bottom of the soil column. The first objective is to assess the effects of the groundwater schemes using a grid size typical of regional climate model simulations at the continental scale (20 km). The phase and amplitude of the fluctuations in the terrestrial water storage over the southern Amazon are improved with one of the groundwater schemes. An increase in the moisture in the top 2 m of the soil is found in those regions where the water table is closer to the land surface, including the western and southern Amazon and the La Plata basin. This induces an increase in ET over the southern La Plata basin, where ET is water limited. There is also a seasonal increase in ET during the dry season over parts of the southern Amazon. The second objective is to assess the role of the horizontal resolution on the effects induced by the Miguez-Macho and Fan groundwater scheme using simulations with grid sizes of 5 and 20 km. Over the La Plata basin, the effect of groundwater on ET is amplified at the 5-km resolution. Notably, over parts of the Amazon, the groundwater scheme increases ET only at the higher 5-km resolution.

A principal component analysis approach to assess CHIRPS precipitation dataset for the study of climate variability of the La Plata Basin, Southern South America

2020 ◽  
Vol 103 (1) ◽  
pp. 767-783
Author(s):  
Wilmar Loaiza Cerón ◽  
Jorge Molina-Carpio ◽  
Irma Ayes Rivera ◽  
Rita Valeria Andreoli ◽  
Mary Toshie Kayano ◽  
...  
Keyword(s):  
Principal Component Analysis ◽  
South America ◽  
Climate Variability ◽  
Principal Component ◽  
Component Analysis ◽  
Analysis Approach ◽  
Southern South America ◽  
La Plata ◽  
La Plata Basin

Recent intensification of extreme precipitation events in the La Plata Basin in Southern South America (1981–2018)

2021 ◽  
Vol 249 ◽  
pp. 105299
Author(s):  
Wilmar L. Cerón ◽  
Mary T. Kayano ◽  
Rita V. Andreoli ◽  
Alvaro Avila-Diaz ◽  
Irma Ayes ◽  
...  
Keyword(s):  
South America ◽  
Extreme Precipitation ◽  
Southern South America ◽  
La Plata ◽  
Extreme Precipitation Events ◽  
La Plata Basin ◽  
Precipitation Events

scholarly journals The impact of near-surface soil moisture assimilation at subseasonal, seasonal, and inter-annual timescales

2015 ◽  
Vol 19 (12) ◽  
pp. 4831-4844 ◽  
Author(s):  
C. Draper ◽  
R. Reichle
Keyword(s):  
Soil Moisture ◽  
Data Assimilation ◽  
Surface Soil ◽  
Root Zone ◽  
Surface Model ◽  
Surface Soil Moisture ◽  
Near Surface ◽  
In Situ Observations ◽  
The Impact

Abstract. A 9 year record of Advanced Microwave Scanning Radiometer – Earth Observing System (AMSR-E) soil moisture retrievals are assimilated into the Catchment land surface model at four locations in the US. The assimilation is evaluated using the unbiased mean square error (ubMSE) relative to watershed-scale in situ observations, with the ubMSE separated into contributions from the subseasonal (SMshort), mean seasonal (SMseas), and inter-annual (SMlong) soil moisture dynamics. For near-surface soil moisture, the average ubMSE for Catchment without assimilation was (1.8 × 10−3 m3 m−3)2, of which 19 % was in SMlong, 26 % in SMseas, and 55 % in SMshort. The AMSR-E assimilation significantly reduced the total ubMSE at every site, with an average reduction of 33 %. Of this ubMSE reduction, 37 % occurred in SMlong, 24 % in SMseas, and 38 % in SMshort. For root-zone soil moisture, in situ observations were available at one site only, and the near-surface and root-zone results were very similar at this site. These results suggest that, in addition to the well-reported improvements in SMshort, assimilating a sufficiently long soil moisture data record can also improve the model representation of important long-term events, such as droughts. The improved agreement between the modeled and in situ SMseas is harder to interpret, given that mean seasonal cycle errors are systematic, and systematic errors are not typically targeted by (bias-blind) data assimilation. Finally, the use of 1-year subsets of the AMSR-E and Catchment soil moisture for estimating the observation-bias correction (rescaling) parameters is investigated. It is concluded that when only 1 year of data are available, the associated uncertainty in the rescaling parameters should not greatly reduce the average benefit gained from data assimilation, although locally and in extreme years there is a risk of increased errors.

scholarly journals 2-way coupling the hydrological land surface model PROMET with the regional climate model MM5

2013 ◽  
Vol 17 (5) ◽  
pp. 1705-1714 ◽  
Author(s):  
F. Zabel ◽  
W. Mauser
Keyword(s):  
Heat Flux ◽  
Land Surface ◽  
Regional Climate ◽  
Surface Processes ◽  
Surface Model ◽  
Land Surface Processes ◽  
Near Surface ◽  
Danube Catchment ◽  
Simulated Precipitation ◽  
The Impact

Abstract. Most land surface hydrological models (LSHMs) consider land surface processes (e.g. soil–plant–atmosphere interactions, lateral water flows, snow and ice) in a spatially detailed manner. The atmosphere is considered as exogenous driver, neglecting feedbacks between the land surface and the atmosphere. On the other hand, regional climate models (RCMs) generally simulate land surface processes through coarse descriptions and spatial scales but include land–atmosphere interactions. What is the impact of the differently applied model physics and spatial resolution of LSHMs on the performance of RCMs? What feedback effects are induced by different land surface models? This study analyses the impact of replacing the land surface module (LSM) within an RCM with a high resolution LSHM. A 2-way coupling approach was applied using the LSHM PROMET (1 × 1 km2) and the atmospheric part of the RCM MM5 (45 × 45 km2). The scaling interface SCALMET is used for down- and upscaling the linear and non-linear fluxes between the model scales. The change in the atmospheric response by MM5 using the LSHM is analysed, and its quality is compared to observations of temperature and precipitation for a 4 yr period from 1996 to 1999 for the Upper Danube catchment. By substituting the Noah-LSM with PROMET, simulated non-bias-corrected near-surface air temperature improves for annual, monthly and daily courses when compared to measurements from 277 meteorological weather stations within the Upper Danube catchment. The mean annual bias was improved from −0.85 to −0.13 K. In particular, the improved afternoon heating from May to September is caused by increased sensible heat flux and decreased latent heat flux as well as more incoming solar radiation in the fully coupled PROMET/MM5 in comparison to the NOAH/MM5 simulation. Triggered by the LSM replacement, precipitation overall is reduced; however simulated precipitation amounts are still of high uncertainty, both spatially and temporally. The distribution of precipitation follows the coarse topography representation in MM5, resulting in a spatial shift of maximum precipitation northwards of the Alps. Consequently, simulation of river runoff inherits precipitation biases from MM5. However, by comparing the water balance, the bias of annual average runoff was improved from 21.2% (NOAH/MM5) to 4.4% (PROMET/MM5) when compared to measurements at the outlet gauge of the Upper Danube watershed in Achleiten.

Species assignment and population genetic studies of Gran Paraná pejerrey (Odontesthes sp., Atheriniformes, Atherinopsidae) from La Plata Basin in South America

Hydrobiologia ◽  
2018 ◽  
Vol 819 (1) ◽  
pp. 243-257 ◽  
Author(s):  
Gabriela Vanina Villanova ◽  
Manuel Vera ◽  
Florencia Brancolini ◽  
Juan Díaz ◽  
Paulino Martinez ◽  
...  
Keyword(s):  
South America ◽  
Population Genetic ◽  
Genetic Studies ◽  
La Plata ◽  
La Plata Basin ◽  
Species Assignment
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