scholarly journals The Impact of Soil Moisture on Precipitation in a Regional Climate Model.

1998 ◽  
Vol 11 (5) ◽  
pp. 482-491
Author(s):  
Shinjiro KANAE ◽  
Taikan OKI ◽  
Katumi MUSIAKE
Keyword(s):  
Soil Moisture ◽  
Regional Climate Model ◽  
Climate Model ◽  
Regional Climate ◽  
The Impact

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.

Sensitivities of isoprene emissions to soil moisture and impacts on surface ozone levels as simulated over the Euro-Mediterranean region by the regional climate model RegCM4.7chem-CLM4.5-MEGAN2.1

2021 ◽  
Author(s):  
Susanna Strada ◽  
Andrea Pozzer ◽  
Graziano Giuliani ◽  
Erika Coppola ◽  
Fabien Solmon ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Water Stress ◽  
Regional Climate Model ◽  
Mediterranean Region ◽  
Control Experiment ◽  
Climate Model ◽  
Surface Ozone ◽  
Regional Climate ◽  
Activity Factor ◽  
Ozone Levels

<p>In response to changes in environmental conditions (e.g., temperature, radiation, soil moisture), plants emit biogenic volatile organic compounds (BVOCs). In the large family of BVOCs, isoprene dominates and plays an important role in atmospheric chemistry. Once released in the atmosphere, isoprene influences levels of ozone, thus affecting both climate and air quality. In turn, climate change may alter isoprene emissions by increasing the occurrence and intensity of severe thermal and water stresses that alter plant functioning. To better constrain the evolution of isoprene emissions under future climates, it is critical to reduce the uncertainties in global and regional estimates of isoprene under present climate. Part of these uncertainties is related to the impact of water stress on isoprene. Recently, the BVOC emission model MEGAN has adopted a more sophisticated soil moisture activity factor γ<sub>sm</sub> which does not only account, as previously, for soil moisture available to plants but also links isoprene emissions to photosynthesis and plant water stress.</p><p>To assess the effects of soil moisture on isoprene emissions and, lastly, on ozone levels in the Euro-Mediterranean region, we use the regional climate model RegCM4.7, coupled to the land surface model CLM4.5, MEGAN2.1 and a chemistry module (RegCM4.7chem-CLM4.5-MEGAN2.1). We have performed a control experiment over 1987-2016 (with a 5-yr spin-up) at a horizontal resolution of 0.22°. Model output from the control experiment is used to initialize RegCM4.7chem-CLM4.5-MEGAN2.1 for the 10 most dry/wet summers (May-August) selected referring to the 1970-2016 precipitation climatology. Each May-August experiment is run with the old and with the new MEGAN soil moisture activity factor γ<sub>sm</sub>.  The results are then compared with a simulation whit no soil moisture activity factor. Both activity factors γ<sub>sm</sub> reduce isoprene emissions under water deficit.</p><p>During dry summers, the old soil moisture activity factor reduces isoprene emissions homogeneously over the model domain by nearly 100%, while ozone levels decrease by around 10%. When the new γ<sub>sm </sub>is used,<sub></sub>isoprene emissions are reduced with a patchy pattern by 10-20%, while ground-surface ozone levels diminish homogeneously by few percent over the southern part of the model domain.</p>

scholarly journals The Cloud_cci simulator for the ESA Cloud_cci climate data record and its application to a global and a regional climate model

2018 ◽  
Author(s):  
Salomon Eliasson ◽  
Karl Göran Karlsson ◽  
Erik van Meijgaard ◽  
Jan Fokke Meirink ◽  
Martin Stengel ◽  
...  
Keyword(s):  
Regional Climate Model ◽  
Climate Model ◽  
Regional Climate ◽  
Cloud Fraction ◽  
Climate Data ◽  
European Continent ◽  
Cloud Properties ◽  
Data Record ◽  
The Impact ◽  
Climate Data Record

Abstract. The Cloud_cci satellite simulator has been developed to enable comparisons between the Cloud_cci Climate Data Record (CDR) and climate models. The Cloud_cci simulator is applied here to the EC-Earth Global Climate Model as well as the RACMO Regional Climate Model. We demonstrate the importance of using a satellite simulator that emulates the retrieval process underlying the CDR as opposed to taking the model output directly. The impact of not sampling the model at the local overpass time of the polar-orbiting satellites used to make the dataset was shown to be large, yielding up to 100 % error in Liquid Water Path (LWP) simulations in certain regions. The simulator removes all clouds with optical thickness smaller than 0.2 to emulate the Cloud_cci CDR's lack of sensitivity to very thin clouds. This reduces Total Cloud Fraction (TCF) globally by about 10 % for EC-Earth and by a few percent for RACMO over Europe. Globally, compared to the Cloud_cci CDR, EC-Earth is shown to be mostly in agreement on the distribution of clouds and their height, but it generally underestimates the high cloud fraction associated with tropical convection regions, and overestimates the occurrence and height of clouds over the Sahara and the Arabian sub-continent. In RACMO, TCF is higher than retrieved over the northern Atlantic Ocean, but lower than retrieved over the European continent, where in addition the Cloud Top Pressure (CTP) is underestimated. The results shown here demonstrate again that a simulator is needed to make meaningful comparisons between modelled and retrieved cloud properties. It is promising to see that for (nearly) all cloud properties the simulator improves the agreement of the model with the satellite data.

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.

scholarly journals Diagnosing Land–Atmosphere Interaction from a Regional Climate Model Simulation over West Africa

2010 ◽  
Vol 11 (2) ◽  
pp. 467-481 ◽  
Author(s):  
Bart J. J. M. van den Hurk ◽  
Erik van Meijgaard
Keyword(s):  
Soil Moisture ◽  
Regional Climate Model ◽  
Climate Model ◽  
Hydrological Cycle ◽  
Regional Climate ◽  
West African ◽  
The West ◽  
Near Surface ◽  
Monsoon Area ◽  
Atmosphere Interaction

Abstract Land–atmosphere interaction at climatological time scales in a large area that includes the West African Sahel has been explicitly explored in a regional climate model (RegCM) simulation using a range of diagnostics. First, areas and seasons of strong land–atmosphere interaction were diagnosed from the requirement of a combined significant correlation between soil moisture, evaporation, and the recycling ratio. The northern edge of the West African monsoon area during June–August (JJA) and an area just north of the equator (Central African Republic) during March–May (MAM) were identified. Further analysis in these regions focused on the seasonal cycle of the lifting condensation level (LCL) and the convective triggering potential (CTP), and the sensitivity of CTP and near-surface dewpoint depressions HIlow to anomalous soil moisture. From these analyses, it is apparent that atmospheric mechanisms impose a strong constraint on the effect of soil moisture on the regional hydrological cycle.

Projected climate change over Kuwait simulated using a WRF high resolution regional climate model

2020 ◽  
Author(s):  
Hussain Alsarraf
Keyword(s):  
Climate Change ◽  
High Resolution ◽  
Regional Climate Model ◽  
Arabian Peninsula ◽  
Climate Model ◽  
Regional Climate ◽  
Dynamic Downscaling ◽  
Model Simulations ◽  
Average Maximum ◽  
The Impact

<p>The purpose of this study is to examine the impact of climate change on the changes on summer surface temperatures between present (2000-2010) and future (2050-2060) over the Arabian Peninsula and Kuwait. In this study, the influence of climate change in the Arabian Peninsula and especially in Kuwait was investigated by high resolution (36, 12, and 4 km grid spacing) dynamic downscaling from the Community Climate System Model CCSM4 using the WRF Weather Research and Forecasting model. The downscaling results were first validated by comparing National Centers for Environmental Prediction NCEP model outputs with the observational data. The global climate change dynamic downscaling model was run using WRF regional climate model simulations (2000-2010) and future projections (2050-2060). The influence of climate change in the Arabian Peninsula can be projected from the differences between the two period’s model simulations. The regional model simulations of the average maximum surface temperature in summertime predicted an increase from 1◦C to 3 ◦C over the summertime in Kuwait by midcentury.</p><p><strong> </strong></p>

scholarly journals Soil moisture in a regional climate model: Simulation and projection

2001 ◽  
Vol 28 (15) ◽  
pp. 2947-2950 ◽  
Author(s):  
Zaitao Pan ◽  
Raymond W. Arritt ◽  
William J. Gutowski ◽  
Eugene S. Takle
Keyword(s):  
Soil Moisture ◽  
Regional Climate Model ◽  
Climate Model ◽  
Model Simulation ◽  
Regional Climate ◽  
Regional Climate Model Simulation ◽  
Climate Model Simulation
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