Development of a dynamic dust source map for NMME-DREAM v1.0 model based on MODIS Normalized Difference Vegetation Index (NDVI) over the Arabian Peninsula

• Main Authors: S. Solomos, A. Abuelgasim, C. Spyrou, I. Binietoglou, S. Nickovic
• Format: Article
• Language: English
• Published: Copernicus Publications 2019-03-01
• Series: Geoscientific Model Development
• Online Access: https://www.geosci-model-dev.net/12/979/2019/gmd-12-979-2019.pdf

<p>We developed a time-dependent dust source map for the NMME Dust Regional Atmospheric Model (DREAM v1.0) based on the satellite MODIS Normalized Difference Vegetation Index (NDVI). Areas with NDVI&thinsp;<span class="inline-formula">&lt;0.1</span> are classified as active dust sources. The updated modeling system is tested for dust emission capabilities over SW Asia using a mesoscale model grid increment of <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M2" display="inline" overflow="scroll" dspmath="mathml"><mrow><mn mathvariant="normal">0.1</mn><msup><mi/><mo>∘</mo></msup><mo>×</mo><mn mathvariant="normal">0.1</mn><msup><mi/><mo>∘</mo></msup></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="52pt" height="11pt" class="svg-formula" dspmath="mathimg" md5hash="0c30464444980c5c328fe69989ce4832"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="gmd-12-979-2019-ie00001.svg" width="52pt" height="11pt" src="gmd-12-979-2019-ie00001.png"/></svg:svg></span></span> for a period of 1 year (2016). Our results indicate significant deviations in simulated aerosol optical depths (AODs) compared to the static dust source approach and general increase in dust loads over the selected domain. Comparison with MODIS AOD indicates a more realistic spatial distribution of dust in the dynamic source simulations compared to the static dust sources approach. The modeled AOD bias is improved from <span class="inline-formula">−0.140</span> to 0.083 for the case of dust events (i.e., for AOD&thinsp;<span class="inline-formula">&gt;0.25</span>) and from <span class="inline-formula">−0.933</span> to <span class="inline-formula">−0.424</span> for dust episodes with AOD&thinsp;<span class="inline-formula">&gt;1</span>. This new development can be easily applied to other time periods, models, and different areas worldwide for a local fine tuning of the parameterization and assessment of its performance.</p>