The spatial distribution of mineral dust and its shortwave radiative forcing over North Africa. Modeling sensitivities to dust emissions and aerosol size treatments
- Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
- Met Office, Exeter (United Kingdom)
A fully coupled meteorology-chemistry-aerosol model (WRF-Chem) with the implementation of two dust emission schemes (GOCART and DUSTRAN) into two aerosol models (MADE/SORGAM and MOSAIC) is applied over North Africa to investigate the modeling sensitivities to dust emissions and aerosol size treatments in simulating mineral dust and its shortwave (SW) radiative forcing. Model results of the spatial distribution of mineral dust and its radiative forcing are evaluated using measurements from the AMMA SOP0 campaign in January and February of 2006 over North Africa. Our study suggests that the size distribution of emitted dust can result in significant differences (up to 100%) in simulating mineral dust and its SW radiative forcing. With the same dust emission and dry deposition processes, two aerosol models, MADE/SORGAM and MOSAIC, can yield large difference in size distributions of dust particles due to their different aerosol size treatments using modal and sectional approaches respectively. However, the difference between the two aerosol models in simulating the mass concentrations and the SW radiative forcing of mineral dust is small (< 10%). The model simulations show that mineral dust increases AOD by a factor of 2, heats the lower atmosphere (1-3 km) with a maximum rate of 0.7±0.5 K day-1 below 1 km, and reduces the downwelling SW radiation by up to 25 W m-2 on 24-hour average at surface, highlighting the importance of including dust radiative impact in understanding the regional climate of North Africa. When compared to the available measurements, WRF-Chem simulations can generally capture the measured features of mineral dust and its radiative properties over North Africa, suggesting that the model can be used to perform more extensive simulations of regional climate over North Africa.
- Research Organization:
- Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- AC05-76RL01830
- OSTI ID:
- 990556
- Report Number(s):
- PNNL-SA-71138; KP1703020; TRN: US201020%%414
- Journal Information:
- Atmospheric Chemistry and Physics, Vol. 10, Issue 18; ISSN 1680-7316
- Publisher:
- European Geosciences Union
- Country of Publication:
- United States
- Language:
- English
Similar Records
Use of ARM observations and numerical models to determine radiative and latent heating profiles of mesoscale convective systems for general circulation models
Regional Modeling of Dust Mass Balance and Radiative Forcing over East Asia using WRF-Chem