An assessment of the impact of initial soil conditions on drought and precipitation extremes by using a high-resolution regional climate model

2021 ◽  
Author(s):  
Juan José Rosa Cánovas ◽  
Matilde García-Valdecasas Ojeda ◽  
Patricio Yeste-Donaire ◽  
Emilio Romero-Jiménez ◽  
María Jesús Esteban-Parra ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Initial Conditions ◽  
Regional Climate ◽  
Precipitation Extremes ◽  
Weather Research And Forecasting ◽  
Soil Conditions ◽  
Forecasting Model ◽  
Initial Soil ◽  
Dry Conditions ◽  
The Impact

<p>Soil moisture (SM) is one of the fields with a relevant role in processes involving land-atmosphere interactions, especially in regions such as the Mediterranean Europe, where coupling between those components of the climate system is very strong. The aim of this study is to address the impact of initial soil conditions on drought and precipitation extremes over the Iberian Peninsula (IP). For this purpose, a dynamical downscalling experiment has been conducted by using the Weather Research and Forecasting model (WRF) along the period 1990-2000. Two one-way nested domains has been considered: a finer domain spanning the IP, with spatial resolution around 10 km, nested within a coarser domain covering the Euro-CORDEX region at 50 km of spatial resolution.</p><p>WRF simulations have been driven with ERA-Interim reanalysis data for all fields except for SM. Initial SM conditions can be divided into three different types: wet, dry and very dry. Values corresponding to initial SM states have been calculated by combining the WRF soil texture map along with the Soil Moisture Index (SMI). For wet conditions, SMI = 1 has been assigned; for dry conditions, SMI = -0.5; and for very dry conditions, SMI = -1. For a grid point with a given texture class, field capacity, wilting point and SMI are used to obtain initial SM. Two different initial dates have been taken into account to also consider the effect of initializing at different moments in the year: 1990-01-01 00:00:00 UTC and 1990-07-01 00:00:00 UTC. Therefore, 6 experimental runs have been carried out (2 initial dates x 3 initial SM). Additionally, a control run full-driven with ERA-Interim has been conducted from 1982 to 2000 to be used as reference. In this context, the impact of initial conditions on different extreme precipitation indices (R5xDay, SDII and R10mm) and on the Standardized Precipitation Index (SPI) for drought has been addressed.</p><p>Results could help to better understand the relevance of land-atmosphere processes in climate modeling, particularly in assessing WRF sensitivity to variations in SM and its skill to detect drought and precipitation extremes. This information could be notably useful in those applications in which initial conditions are especially relevant, such as the seasonal-to-decadal climate prediction.</p><p>Keywords: soil moisture, initial conditions, precipitation extremes, drought, regional climate, Weather Research and Forecasting model</p><p>ACKNOWLEDGEMENTS: JJRC acknowledges the Spanish Ministry of Science, Innovation and Universities for the predoctoral fellowship (grant code: PRE2018-083921). This research has been carried out in the framework of the projects CGL2017-89836-R, funded by the Spanish Ministry of Economy and Competitiveness with additional FEDER funds, and B-RNM-336-UGR18, funded by FEDER / Junta de Andalucía - Ministry of Economy and Knowledge.</p>

Impact of Soil Moisture Initialization on Temperature Extreme Detection in the context of Regional Climate Modeling

2020 ◽  
Author(s):  
Matilde García-Valdecasas Ojeda ◽  
Juan José Rosa-Cánovas ◽  
Emilio Romero-Jiménez ◽  
Patricio Yeste ◽  
Sonia R. Gámiz-Fortis ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Initial Conditions ◽  
Climate Modeling ◽  
Regional Climate ◽  
Wrf Model ◽  
Regional Climate Modeling ◽  
Weather Research And Forecasting ◽  
Temperature Extremes ◽  
Temperature Extreme ◽  
The Impact

<p>Land surface-related processes play an essential role in the climate conditions at a regional scale. In this study, the impact of soil moisture (SM) initialization on regional climate modeling has been explored by using a dynamical downscaling experiment. To this end, the Weather Research and Forecasting (WRF) model was used to generate a set of high-resolution climate simulations driven by the ERA-Interim reanalysis for a period from 1989 to 2009. As the spatial configuration, two one-way nested domains were used, with the finer domain being centered over the Iberian Peninsula (IP) at a spatial resolution of about 10 km, and nested over a coarser domain that covers the Euro-CORDEX region at 50 km of spatial resolution.</p><p>The sensitivity experiment consisted of two control runs (CTRL) performed using as SM initial conditions those provided by ERA-Interim, and initialized for two different dates times (January and June). Additionally, another set of runs was completed driven by the same climate data but using as initial conditions prescribed SM under wet and dry scenarios.</p><p>The study is based on assessing the WRF performance by comparing the CTRL simulations with those performed with the different prescribed SM, and also, comparing them with the observations from the Spanish Temperature At Daily scale (STEAD) dataset. In this sense, we used two temperature extreme indices within the framework of decadal predictions: the warm spell index (WSDI) and the daily temperature range (DTR).</p><p>These results provide valuable information about the impact of the SM initial conditions on the ability of the WRF model to detect temperature extremes, and how long these affect the regional climate in this region. Additionally, these results may provide a source of knowledge about the mechanisms involved in the occurrence of extreme events such as heatwaves, which are expected to increase in frequency, duration, and magnitude under the context of climate change.</p><p><strong>Keywords</strong>: soil moisture initial conditions, temperature extremes, regional climate, Weather Research and Forecasting model</p><p>Acknowledgments: This work has been financed by the project CGL2017-89836-R (MINECO-Spain, FEDER). The WRF simulations were performed in the Picasso Supercomputer at the University of Málaga, a member of the Spanish Supercomputing Network.</p>

Modeling of Forecast Sensitivity on the March of Monsoon Isochrones from Kerala to New Delhi: The First 25 Days

2012 ◽  
Vol 69 (8) ◽  
pp. 2465-2487 ◽  
Author(s):  
T. N. Krishnamurti ◽  
Anu Simon ◽  
Aype Thomas ◽  
Akhilesh Mishra ◽  
Dev Sikka ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Temporal Variability ◽  
Weather Research And Forecasting ◽  
Forecasting Model ◽  
Model Parameters ◽  
New Delhi ◽  
The North ◽  
Sensitivity Studies ◽  
Dry Soil ◽  
The Impact

Abstract This study addresses observational and modeling sensitivity on the march of the onset isochrones of the Indian summer monsoon. The first 25 days of the passage of the isochrones of monsoon onset is of great scientific interest. Surface and satellite-based datasets are used for high-resolution modeling of the impact of the motion of the onset isochrones from Kerala to New Delhi. These include the asymmetries across the isochrone such as soil moisture and its temporal variability, moistening of the dry soil to the immediate north of the isochrone by nonconvective anvil rains, and formation of newly forming cloud elements to the immediate north of the isochrone. The region immediately north of the isochrone is shown to carry a spread of buoyancy elements. As these new elements grow, they are continually being steered by the divergent circulations of the parent isochrone to the north and eventually to the northwest. CloudSat was extremely useful for identifying the asymmetric cloud structures across the isochrone. In the modeling sensitivity studies, the authors used a mesoscale Advanced Research Weather Research and Forecasting Model (ARW-WRF) to examine days 1–25 of forecasts of the onset isochrone. Prediction experiments were first modeled during normal, dry, and wet Indian monsoons using default values of model parameters. This study was extended to determine the effects of changes in soil moisture and nonconvective rain parameterizations (the parameters suggested by the satellite observations). These sensitivity experiments show that the motion of the isochrones from Kerala to New Delhi are very sensitive to the parameterization of soil moisture and nonconvective anvil rains immediately north of the isochrone.

scholarly journals Impact of Soil Moisture Anomalies on Summer Rainfall over East Asia: A Regional Climate Model Study

2007 ◽  
Vol 20 (23) ◽  
pp. 5732-5743 ◽  
Author(s):  
Jung-Eun Kim ◽  
Song-You Hong
Keyword(s):  
Soil Moisture ◽  
East Asia ◽  
Large Scale ◽  
Climate Model ◽  
Regional Climate ◽  
Summer Rainfall ◽  
Department Of Energy ◽  
Initial Soil Moisture ◽  
Initial Soil ◽  
The Impact

Abstract Numerous modeling studies have shown that soil moisture anomalies in later spring have a significant effect on the summer rainfall anomalies in North America. On the other hand, the role of soil moisture in forming monsoonal precipitation in East Asia has not been identified. This study attempts to clarify the importance of soil moisture on the summer rainfall in late spring in East Asia. The National Centers for Environmental Prediction (NCEP) Regional Spectral Model (RSM) is utilized for 3-month (June–August) simulations in 1998 (above-normal precipitation year) and 1997 (below-normal precipitation year). Initial and boundary conditions are derived from the NCEP–Department of Energy (DOE) reanalysis. The control run uses the initial soil moisture from the reanalysis, whereas it is set as a saturation and wilting point for “wet” and “dry” experiments, respectively. The impact of soil moisture anomalies on the simulated summer rainfall in East Asia is not significant. The change in precipitation between the wet and dry experiments is about 10%. A conflict between the local feedback of soil moisture and a change in large-scale circulations associated with the summertime monsoonal circulation in East Asia can be attributed as a reason for this anomaly. It is found that enhanced (suppressed) evaporation from the soil to the atmosphere in wet (dry) initial soil moisture reduces (increases) the land–sea contrast between East Asia and the Pacific Ocean, leading to a weakened sensitivity of the monsoonal circulations to the initial soil moisture. It can be concluded that the impact of the initial soil moisture is significant on the dynamic circulation in East Asia.

scholarly journals Influence of initial soil moisture in a Regional Climate Model study over West Africa: Part 1: Impact on the climate mean

2020 ◽  
Author(s):  
Brahima Koné ◽  
Arona Diedhiou ◽  
Adama Diawara ◽  
Sandrine Anquetin ◽  
N'datchoh Evelyne Touré ◽  
...  
Keyword(s):  
Soil Moisture ◽  
West Africa ◽  
Regional Climate Model ◽  
Climate Model ◽  
Regional Climate ◽  
Theoretical Physics ◽  
Near Surface ◽  
Initial Soil Moisture ◽  
Initial Soil ◽  
The Impact

Abstract. The impact of the anomalies in initial soil moisture in later spring on the subsequent mean climate over West Africa is examined using the latest version of Regional Climate Model of the International Centre for Theoretical Physics (RegCM4). We performed this sensitivity studies over the West African domain, for June–July–August–September (JJAS) 2003 (wet year) and JJAS 2004 (a dry year) at the horizontal resolution of 25 km × 25 km. The reanalysis soil moisture of the European Centre Meteorological Weather Forecast's reanalysis of the 20th century (ERA20C) were used to initialize the control runs, whereas we initialized the soil moisture at the wilting points and field capacity respectively in dry and wet experiments. The impact of the anomalies in initial soil moisture on the precipitation in West Africa is homogeneous only over the central Sahel where dry (wet) experiments lead to rainfall decrease (increase). The strongest impact on precipitation in wet and dry experiments is found respectively over west and central Sahel with the peak of change about respectively 40 % and −8 %. The impact of the anomalies in initial soil moisture can persist for three or even four months, however the significance influence on precipitation, greater than 1 mm day−1, of the impact of the anomalies in initial soil moisture is much shorter, no longer than one month. The effect of soil moisture anomalies is mostly confined to the near-surface climate and in the upper troposphere. Overall, the impact of the anomalies in initial soil moisture is greater on temperature than on precipitation over most areas studied. The strongest homogeneous impacts of the anomalies in initial soil moisture on temperature is located over the central Sahel with the peak of change at −1.5 °C and 0.5 °C respectively in wet and dry experiments. The influence of initial the anomalies in initial soil moisture on the precipitation mechanism is also highlighted. We will investigate in the Part II of this study the influence of the anomalies in initial soil moisture on climate extremes.

scholarly journals Influence of initial soil moisture in a Regional Climate Model study over West Africa. Part 2: Impact on the climate extremes

2020 ◽  
Author(s):  
Brahima Koné ◽  
Arona Diedhiou ◽  
Adama Diawara ◽  
Sandrine Anquetin ◽  
N'datchoh Evelyne Touré ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Minimum Temperature ◽  
Climate Model ◽  
Regional Climate ◽  
Maximum Temperature ◽  
Initial Soil Moisture ◽  
Initial Soil ◽  
Temperature Indices ◽  
The Impact ◽  
Precipitation Events

Abstract. The influence of the anomalies in initial soil moisture on the climate extreme over West Africa is investigated using the fourth generation of Regional Climate Model coupled to the version 4.5 of the Community Land Model (RegCM4-CLM4.5). We applied the initial soil moisture on June 1st for two summers June–July–August–September (JJAS) 2003 and JJAS 2004 (Resp. wet and dry year in the region of interest) with 25 km of spatial resolution. We initialized the control runs with the reanalysis soil moisture of the European Centre Meteorological Weather Forecast's reanalysis of the 20th century (ERA20C), while for the dry and wet experiments, we initialized the soil moisture respectively at the wilting points and field capacity. The impact on extreme precipitation indices of the initial soil moisture, especially over the central Sahel, is homogeneous, i.e. dry (wet) experiments tend to decrease (increase) precipitation extreme indices only for precipitation indices related to the number of precipitation events, not for those related to the intensity of precipitation events. Overall, the impact on temperature extremes of the anomalies in initial soil moisture is more significant compared to precipitation extremes. Initial soil moisture anomalies unequally affect daily minimum and maximum temperature. A stronger impact is found on maximum temperature than minimum temperature. Over the entire West African domain, wet (dry) experiments cause a decrease (increase) in maximum temperature. The strongest impacts on minimum temperature indices are found mainly in wet experiments, on the Sahara where we found the higher values of the maximum and minimum daily minimum temperature indices (resp. TNx and TNn). The performance of RegCM4-CLM4.5 in simulating the ten (10) extreme rainfall and temperature indices used in this study is also highlighted.

The impact of wheat stubble on evaporation from a sandy soil

2009 ◽  
Vol 60 (8) ◽  
pp. 730 ◽  
Author(s):  
P. R. Ward ◽  
K. Whisson ◽  
S. F. Micin ◽  
D. Zeelenberg ◽  
S. P. Milroy
Keyword(s):  
Soil Water ◽  
Sandy Soil ◽  
Water Storage ◽  
Soil Water Storage ◽  
Soil Conditions ◽  
Adjacent Area ◽  
Stubble Retention ◽  
Dry Conditions ◽  
Wheat Stubble ◽  
The Impact

In Mediterranean-type climates, dryland soil water storage and evaporation during the hot and dry summer are poorly understood, particularly for sandy-textured soils. Continued evaporation during summer, and any effects of crop stubble management, could have a significant impact on annual components of the water balance and crop yield. In this research, the effect of wheat stubble management on summer evaporation and soil water storage was investigated for a sandy soil in south-western Australia, during the summers of 2005–06 and 2006–07. Treatments comprised: retained standing stubble; retained flattened stubble; removed stubble; and removed stubble followed by burying the crowns with topsoil from an adjacent area. Under ‘dry’ conditions, evaporation continued at ~0.2 mm/day. In contrast to previous results for finer textured soil types, stubble retention did not decrease the rate of evaporation, but marginally (10–30%) increased evaporation on 7 out of 14 days when measurements were taken. Significant differences due to stubble management were observed in two successive summers, but only for relatively dry soil conditions. There were no significant differences observed for several days after irrigation or rainfall. Under dry conditions in the absence of rainfall, total decrease in water storage during a 90-day summer period could be ~20 mm, but differences attributable to stubble management are likely to be a few mm.

scholarly journals The Impact of Dry Midlevel Air on Hurricane Intensity in Idealized Simulations with No Mean Flow

2012 ◽  
Vol 69 (1) ◽  
pp. 236-257 ◽  
Author(s):  
Scott A. Braun ◽  
Jason A. Sippel ◽  
David S. Nolan
Keyword(s):  
Vortex Core ◽  
Inner Core ◽  
Weather Research And Forecasting ◽  
Forecasting Model ◽  
Vortex Center ◽  
Latent Heating ◽  
Initial Radius ◽  
Mean Flow ◽  
Dry Air ◽  
The Impact

Abstract This study examines the potential negative influences of dry midlevel air on the development of tropical cyclones (specifically, its role in enhancing cold downdraft activity and suppressing storm development). The Weather Research and Forecasting model is used to construct two sets of idealized simulations of hurricane development in environments with different configurations of dry air. The first set of simulations begins with dry air located north of the vortex center by distances ranging from 0 to 270 km, whereas the second set of simulations begins with dry air completely surrounding the vortex, but with moist envelopes in the vortex core ranging in size from 0 to 150 km in radius. No impact of the dry air is seen for dry layers located more than 270 km north of the initial vortex center (~3 times the initial radius of maximum wind). When the dry air is initially closer to the vortex center, it suppresses convective development where it entrains into the storm circulation, leading to increasingly asymmetric convection and slower storm development. The presence of dry air throughout the domain, including the vortex center, substantially slows storm development. However, the presence of a moist envelope around the vortex center eliminates the deleterious impact on storm intensity. Instead, storm size is significantly reduced. The simulations suggest that dry air slows intensification only when it is located very close to the vortex core at early times. When it does slow storm development, it does so primarily by inducing outward-moving convective asymmetries that temporarily shift latent heating radially outward away from the high-vorticity inner core.

scholarly journals Earthworms are little affected by reduced soil tillage methods in vineyards

2017 ◽  
Vol 63 (No. 6) ◽  
pp. 257-263 ◽  
Author(s):  
Faber Florian ◽  
Wachter Elisabeth ◽  
Zaller Johann G
Keyword(s):  
Soil Moisture ◽  
Soil Temperature ◽  
Soil Tillage ◽  
Soil Conditions ◽  
Reduced Tillage ◽  
No Tillage ◽  
Dry Soil ◽  
The Impact ◽  
Tillage Methods ◽  
Erosion Prevention

Inter-rows in vineyards are commonly tilled in order to control weeds and/or to conserve water. While impacts of tillage on earthworms are well studied in arable systems, very little is known from vineyards. In an experimental vineyard, the impact of four reduced tillage methods on earthworms was examined: rotary hoeing, rotary harrowing, grubbing and no tillage. According to an erosion prevention programme, tillage was applied every other inter-row only while alternating rows retained vegetated. Earthworms were extracted from the treated inter-rows 10, 36, 162 and 188 days after tillage. Across dates, tillage methods had no effect on overall earthworm densities or biomass. Considering each sampling date separately, earthworm densities were affected only at day 36 after tillage leading to lower densities under rotary hoeing (150.7 ± 42.5 worms/m<sup>2</sup>) and no tillage (117.3 ± 24.8 worms/m<sup>2</sup>) than under rotary harrowing (340.0 ± 87.4 worms/m<sup>2</sup>) and grubbing (242.7 ± 43.9 worms/m<sup>2</sup>). Time since tillage significantly increased earthworm densities or biomass, and affected soil moisture and temperature. Across sampling dates, earthworm densities correlated positively with soil moisture and negatively with soil temperature; individual earthworm mass increased with increasing time since tillage. It was concluded that reduced tillage in vineyards has little impact on earthworms when applied in spring under dry soil conditions.

scholarly journals Investigating the impact of initial soil moisture conditions on total infiltration by using an adapted double-ring infiltrometer

2016 ◽  
pp. 1-17 ◽  
Author(s):  
Romed Ruggenthaler ◽  
Gertraud Meißl ◽  
Clemens Geitner ◽  
Georg Leitinger ◽  
Nikolaus Endstrasser ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Double Ring ◽  
Initial Soil Moisture ◽  
Initial Soil ◽  
Moisture Conditions ◽  
The Impact

scholarly journals Diagnosing the Strength of Land–Atmosphere Coupling at Subseasonal to Seasonal Time Scales in Asia

2014 ◽  
Vol 15 (1) ◽  
pp. 320-339 ◽  
Author(s):  
Di Liu ◽  
Guiling Wang ◽  
Rui Mei ◽  
Zhongbo Yu ◽  
Huanghe Gu
Keyword(s):  
Soil Moisture ◽  
Time Scales ◽  
Climate Model ◽  
Regional Climate ◽  
Precipitation Amount ◽  
Data Sources ◽  
Conditional Correlation ◽  
Global Land ◽  
Land Data Assimilation System ◽  
The Impact

Abstract This paper focuses on diagnosing the strength of soil moisture–atmosphere coupling at subseasonal to seasonal time scales over Asia using two different approaches: the conditional correlation approach [applied to the Global Land Data Assimilation System (GLDAS) data, the Climate Forecast System Reanalysis (CFSR) data, and output from the regional climate model, version 4 (RegCM4)] and the Global Land–Atmosphere Coupling Experiment (GLACE) approach applied to the RegCM4. The conditional correlation indicators derived from the model output and the two observational/reanalysis datasets agree fairly well with each other in the spatial pattern of the land–atmosphere coupling signal, although the signal in CFSR data is stronger and spatially more extensive than the GLDAS data and the RegCM4 output. Based on the impact of soil moisture on 2-m air temperature, the land–atmosphere coupling hotspots common to all three data sources include the Indochina region in spring and summer, the India region in summer and fall, and north-northeastern China and southwestern Siberia in summer. For precipitation, all data sources produce a weak and spatially scattered signal, indicating the lack of any strong coupling between soil moisture and precipitation, for both precipitation amount and frequency. Both the GLACE approach and the conditional correlation approach (applied to all three data sources) identify evaporation and evaporative fraction as important links for the coupling between soil moisture and precipitation/temperature. Results on soil moisture–temperature coupling strength from the GLACE-type experiment using RegCM4 are in good agreement with those from the conditional correlation analysis applied to output from the same model, despite substantial differences between the two approaches in the terrestrial segment of the land–atmosphere coupling.

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