Sensitivity of WRF-chem predictions to dust source function specification in West Asia

Autor(en)

Seyed Omid Nabavi, Leopold Haimberger, Cyrus Samimi

Abstrakt

Dust storms tend to form in sparsely populated areas covered by only few observations. Dust source maps, known as source functions, are used in dust models to allocate a certain potential of dust release to each place. Recent research showed that the well known Ginoux source function (GSF), currently used in Weather Research and Forecasting Model coupled with Chemistry (WRF-chem), exhibits large errors over some regions in West Asia, particularly near the IRAQ/Syrian border. This study aims to improve the specification of this critical part of dust forecasts. A new source function based on multi-year analysis of satellite observations, called West Asia source function (WASF), is therefore proposed to raise the quality of WRF-chem predictions in the region. WASF has been implemented in three dust schemes of WRF-chem. Remotely sensed and ground-based observations have been used to verify the horizontal and vertical extent and location of simulated dust clouds. Results indicate that WRF-chem performance is significantly improved in many areas after the implementation of WASF. The modified runs (long term simulations over the summers 2008–2012, using nudging) have yielded an average increase of Spearman correlation between observed and forecast aerosol optical thickness by 12–16 percent points compared to control runs with standard source functions. They even outperform MACC and DREAM dust simulations over many dust source regions. However, the quality of the forecasts decreased with distance from sources, probably due to deficiencies in the transport and deposition characteristics of the forecast model in these areas. © 2016

Organisation(en)

Institut für Meteorologie und Geophysik

Externe Organisation(en)

Universität Bayreuth

Journal

Aeolian Research

Band

24

Seiten

115-131

Anzahl der Seiten

17

ISSN

1875-9637

DOI

https://doi.org/10.1016/j.aeolia.2016.12.005

Publikationsdatum

08-2016

Peer-reviewed

Ja

ÖFOS 2012

105906 Umweltgeowissenschaften, 105206 Meteorologie

Schlagwörter

ASJC Scopus Sachgebiete

Earth-Surface Processes, Geology

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/sensitivity-of-wrfchem-predictions-to-dust-source-function-specification-in-west-asia(e4f79f0f-5376-41fc-9c38-6a0001fe3d0d).html