Development and evaluation of desert dust emission model

Abstract

The Phd Thesis aims on the development and the update of the dust modulewithin the Natural Emissions MOdel (NEMO) for applications on arid andsemi-arid areas. The new dust module incorporates all the recent, state-of-art parameterizations, related to the physical mechanisms of wind-blown dustemissions. The updated dust module of NEMO enable the investigation of thedierences originated from these parameterizations, in terms of dust emissions,as well the possibility to evaluate them and distinguish the best performingcombination(s).This study focuses on: a) the investigation of the variations produced fromthe three main components of the dust emissions mechanism, namely the hor-izontal mass ux, the drag partition eciency and the sandblasting eciencyand b) the evaluation of all possible combinations with these parameterizations.The above are implemented at the Central Middle East area (CME), a regionwhere these parameterizations are less studied, with signicant dust sourcesand with available for evaluation data. The studied period selected is fromApril to June of 2015, where the dust events are more frequent. A total of 16congurations with all possible combinations is utilized in order to investigateconcretely the variations resulting from these parameterizations themselves.The rst part focuses on the dierences among the 16 simulations for eachparameterization of interest is done, in terms of emissions uxes with abso-lute and relative values. Maps that emphasize their spatial dierences in CMEare also utilized. The total emissions' budget is also calculated for all cong-urations.The nal goal of this procedure is the quantication of their relativeimportance in terms of emissions, and their prioritization, creating a benchmarkfor future studies.The second part focuses on the evaluation of these 16 congurations andthe distinction of the best performing conguration(s). Their assessment is re-alized qualitatively with the aid of the MODIS Aerosol Optical Depths at 550nm and quantitatively on-site measurements of PM10 concentrations for thedays with signicant dust events. For the quantitative assessment, two meth-ods are applied in order to nd concretely the best performing conguration(s):the application of a 50% acceptable level of uncertainty , utilizing all the com-mon statistics and b) the FAIRMODE method, which enables, apart from thequantitative assessment, the determination of the origins of the uncertainties.

Αντικείμενο της διατριβής αυτής είναι η μελέτη των παραμετροποιήσεων μοντελοποίησης της σκόνης από ερημικές και ημιερημικές περιοχές, μέσω της ανάπτυξης και αξιολόγησης μοντέλου φυσικών εκπομπών. Στο πλαίσιο του διδακτορικού αναπτύχθηκαν και επικαιροποιήθηκαν οι αλγόριθμοι του μοντέλου φυσικών εκπομπών ΝΕΜΟ, το οποίο έχει αναπτυχθεί στο Εργαστήριο Φυσικής της Ατμόσφαιρας του Α.Π.Θ., ώστε να αποδίδει και την παραγωγή ερημικής σκόνης. Οι παραμετροποίήσεις που αναπτύχθηκαν στο ΝΕΜΟ εφαρμόστηκαν στην περιοχή της Μέσης Ανατολής, προκειμένου να αναλυθούν οι διαφοροποιήσεις σε επίπεδο εκπομπών, καθώς και να αξιολογηθούν με τελικό σκοπό την ανεύρεση του βέλτιστου συνδυασμού(ων) παραμετροποιήσεων.