Impact of surface roughness and soil texture on mineral dust emission fluxes modeling

Abstract

[1] Dust production models (DPM) used to estimate vertical fluxes of mineral dust aerosols over arid regions need accurate data on soil and surface properties. The Laboratoire Inter-Universitaire des Systemes Atmospheriques (LISA) data set was developed for Northern Africa, the Middle East, and East Asia. This regional data set was built through dedicated field campaigns and include, among others, the aerodynamic roughness length, the smooth roughness length of the erodible fraction of the surface, and the dry (undisturbed) soil size distribution. Recently, satellite-derived roughness length and high-resolution soil texture data sets at the global scale have emerged and provide the opportunity for the use of advanced schemes in global models. This paper analyzes the behavior of the ERS satellite-derived global roughness length and the State Soil Geographic data base-Food and Agriculture Organization of the United Nations (STATSGO-FAO) soil texture data set (based on wet techniques) using an advanced DPM in comparison to the LISA data set over Northern Africa and the Middle East. We explore the sensitivity of the drag partition scheme (a critical component of the DPM) and of the dust vertical fluxes (intensity and spatial patterns) to the roughness length and soil texture data sets. We also compare the use of the drag partition scheme to a widely used preferential source approach in global models. Idealized experiments with prescribed wind speeds show that the ERS and STATSGO-FAO data sets provide realistic spatial patterns of dust emission and friction velocity thresholds in the region. Finally, we evaluate a dust transport model for the period of March to July 2011 with observed aerosol optical depths from Aerosol Robotic Network sites. Results show that ERS and STATSGO-FAO provide realistic simulations in the region.Citation: Menut, L., C. Pérez, K. Haustein, B. Bessagnet, C. Prigent, and S. Alfaro (2013), Impact of surface roughness and soil texture on mineral dust emission fluxes modeling,

Curriculum vitae of the LOTOS–EUROS (v2.0) chemistry transport model

“…A future development would be to include a roughness length map instead of a using fixed roughness length for land use categories (e.g. Menut et al, 2013b), which is particularly relevant for areas which are classified as desert but in which the nature of this desert varies strongly per region. This could be achieved relatively easily.…”

“…Good modelling of mineral dust emissions is a challenge and results from different models are easily a factor of 10 apart. This is because generation of windblown dust is very sensitive to local wind speed and to regional and local roughness length (Menut et al, 2013b) and soil char- acteristics (Mokhtari et al, 2012). Therefore all models use tuning factors to come to optimal settings for the region of interest.…”

Ozone and aerosol tropospheric concentrations variability analyzed using the ADRIMED measurements and the WRF and CHIMERE models

“…In addition to this version, several processes were improved and added in the framework of this study. First, the mineral dust emissions are now calculated using new soil and surface databases, (Menut et al, 2013b) and with a spatial extension of potentially emitting areas in Europe as described in Briant et al (2014).…”

“…The meteorological modeling was already done and evaluate with the WRF model, for the same kind of domain and resolution as in and Menut et al (2013b, c) for example. It was shown that the model is able to accurately reproduce the main meteorological variables over the Euro- Mediterranean area: the day-to-day and hourly variabilities are well reproduced for all variables, the biases are known and the model representativity is adapted to the main variations of gaseous and aerosol formation and transport.…”

“…For example, ozone was simulated using the CHIMERE regional CTM during the ESCOMPTE campaign (Menut et al, 2005) and the summertime ozone maximum was analyzed using the TOMCAT global CTM (Richards et al, 2013). Aerosol observations in the Mediterranean area often show large contributions from mineral dust, so that numerous studies were devoted to this species (Pérez et al, 2011;Nabat et al, 2012;Menut et al, 2013b;de la Paz et al, 2013). Their impact on climate via their radiative effect was recently analyzed with the models COSMO (Vogel et al, 2009), RegCM (Santese et al, 2010), SKYRON (Spyrou et al, 2013) and ALADIN-Climate .…”