Impact of soil moisture initialisation and lateral boundary conditions on regional climate model simulations of the West African Monsoon

Moufouma-Okia, Wilfran; Rowell, David P.

doi:10.1007/s00382-009-0638-0

Cited by 47 publications

(31 citation statements)

References 87 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…At higher temporal resolution, features like the seasonal cycle and the onset of the rainy season are studied to form the basis of a significant assessment of the models performance in simulating these critical characteristics of West Africa climate. The last step investigates projected future climate, with a special emphasis on precipitation, considered as the most difficult parameter to simulate [5] [9] [10] [11]. Statistical methods employed include correlation, variability and error assessments using Taylor diagrams [23], linear regression and coefficient of variation for long-term trends for both historical and projected periods.…”

Section: Investigation Methodsmentioning

confidence: 99%

Multi-Scale Characteristics of Precipitation and Temperature over West Africa Using SMHI-RCA Driven by GCMs under RCP8.5

Sarr¹

2017

AJCC

View full text Add to dashboard Cite

In this paper, we use simulations from the Swedish Meteorological and Hydrological Institute (SMHI) regional climate model (RCM) version 3.5 (SMHI-RCA3.5) following a multi-GCM boundary forcing approach. The model is run at a horizontal resolution of 50 km on the CORDEX-AFRICA domain. Key characteristics of precipitation, mean temperature and its extremes (minimum and maximum temperature) have been investigated over West Africa and on 3 designed sub-domains, the Sahel (SAH), the Senegal-Gambia ( The regional climate model RCA, forced by the reanalysis ERA-Interim, 6 CMIP5 GCMs and their ensemble, reproduces realistically the climatology of precipitation and temperatures over West Africa. Compared to observed datasets GPCP for precipitation and CRU for temperature, the ensemble outperforms both other GCMs and the verification model (ERA-Interim). The major biases in precipitation are the early onset over the Sahel and the little dry season (LDS), from mid-July to mid-September over the Gulf of Guinea, and a few models either overestimate and/or reflect rather poorly. The strong warming in extreme temperatures (minimum and maximum) combined with the drying mainly over Western Sahel (SEN) found in this study will very likely impact notably a vital sector like agriculture, both during the near and far terms.

show abstract

Section: Investigation Methodsmentioning

confidence: 99%

Multi-Scale Characteristics of Precipitation and Temperature over West Africa Using SMHI-RCA Driven by GCMs under RCP8.5

Sarr¹

2017

AJCC

View full text Add to dashboard Cite

show abstract

“…Gaertner et al [286] found that introducing a soil moisture perturbation into a model had different effects at different scales: a reduction in rainfall over the wet path itself but a net increase in rainfall over a larger area. Moufouma-Okia and Rowell [287], using a regional climate model, found that soil moisture anomalies had little impact on the overall amount of rainfall, creating only small and random intraseasonal, interannual and spatial variations. However, they noted that the conclusion may be model dependent or influenced by the initial soil moisture data introduced into the model.…”

Section: Relationship Between Land-surface Characteristics Andmentioning

confidence: 99%

The West African Sahel: A Review of Recent Studies on the Rainfall Regime and Its Interannual Variability

2013

View full text Add to dashboard Cite

The West African Sahel is well known for the severe droughts that ravaged the region in the 1970s and 1980s. Meteorological research on the region has flourished during the last decade as a result of several major field experiments. This paper provides an overview of the results that have ensued. A major focus has been on the West African monsoon, a phenomenon that links all of West Africa. The characteristics and revised picture of the West African monsoon are emphasized. Other topics include the interannual variability of rainfall, the atmospheric circulation systems that govern interannual variability, characteristics of precipitation and convection, wave activity, large-scale factors in variability (including sea-surface temperatures), and land-atmosphere relationships. New paradigms for the monsoon and associated ITCZ and for interannual variability have emerged. These emphasize features in the upper atmosphere, as well as the Saharan Heat Low. Feedback mechanisms have also been emphasized, especially the coupling of convection with atmospheric dynamics and with land surface characteristics. New results also include the contrast between the premonsoon and peak monsoon seasons, two preferred modes of interannual variability (a latitudinal displacement of the tropical rainbelt versus changes in its intensity), and the critical importance of the Tropical Easterly Jet.

show abstract

“…Because of the importance of land surface processes in regional dynamic downscaling, a number of studies have investigated the impact of specification of initial soil moisture and land conditions from data assimilation systems and satellite products (e.g., Pielke et al, 1997;Hong et al, 2009;Moufouma-Okia and Rowell, 2010;Sertel et al, 2010;Panegrossi et al, 2011). Using high resolution soil moisture data derived from ENVISAT/ASAR observations as the initial conditions for the MM5 simulation of the Tanaro flood event of April 2009, the ASAR-derived soil moisture field shows significantly drier conditions compared to the ECMWF analysis and significantly improved the simulation in timing of the onset of the precipitation, as well as the intensity of rainfall and the location of rain/no rain areas (Panegrossi et al, 2011).…”

Section: Specification Of Initial Soil Moisture and Vegetation Conditmentioning

confidence: 99%

A review on regional dynamical downscaling in intraseasonal to seasonal simulation/prediction and major factors that affect downscaling ability

Xue

Janjić

Dudhia

et al. 2014

Atmospheric Research

214

135

View full text Add to dashboard Cite

Regional climate models (RCMs) have been developed and extensively applied for dynamically downscaling coarse resolution information from different sources, such as general circulation models (GCMs) and reanalyses, for different purposes including past climate simulations and future climate projection. Thus far, the nature, the methods, and a number of crucial issues concerning the use of dynamic downscaling are still not well understood. The most important issue is whether, and if so, under what conditions dynamic downscaling is really capable of adding more information at different scales compared to the GCM or reanalysis that imposes lateral boundary conditions (LBCs) to the RCMs. There are controversies regarding the downscaling ability. In this review paper we present several factors that have consistently demonstrated strong impact on dynamic downscaling ability in intraseasonal and seasonal simulations/predictions and future projection. Those factors include setting of the RCM experiment (e.g. imposed LBC quality, domain size and position, LBC coupling, and horizontal resolution); as well as physical processes, mainly convective schemes and vegetation and soil processes that include initializations, vegetation specifications, and planetary boundary layer and surface coupling. These studies indicate that RCMs have downscaling ability in some aspects but only under certain conditions. Any significant weaknesses in one of these aspects would cause an RCM to lose its dynamic downscaling ability. This paper also briefly presents challenges faced in current RCM dynamic downscaling and future prospective, which cover the application of coupled ocean-atmosphere RCMs, ensemble applications, and future projections.

show abstract

Impact of soil moisture initialisation and lateral boundary conditions on regional climate model simulations of the West African Monsoon

Cited by 47 publications

References 87 publications

Multi-Scale Characteristics of Precipitation and Temperature over West Africa Using SMHI-RCA Driven by GCMs under RCP8.5

Multi-Scale Characteristics of Precipitation and Temperature over West Africa Using SMHI-RCA Driven by GCMs under RCP8.5

The West African Sahel: A Review of Recent Studies on the Rainfall Regime and Its Interannual Variability

A review on regional dynamical downscaling in intraseasonal to seasonal simulation/prediction and major factors that affect downscaling ability

Contact Info

Product

Resources

About