Forecasting smoke and dust using HYSPLIT Smoke Forecast

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Forecasting smoke and dust using HYSPLIT

Forecasting smoke and dust using HYSPLIT

Smoke Forecast System • Experimental testing phase began March 28, 2006 • Run daily

Smoke Forecast System • Experimental testing phase began March 28, 2006 • Run daily at NCEP using the 6 Z cycle to produce a 24 hr analysis and a 48 -hr forecast Computational Cycle Daily Procedure • Satellite detection of fire location and heat released • Calculation of emissions • HYSPLIT run • Statistics calculation • Web distribution All smoke particles and continuous fires initialize the next day’s calculation

Hazard Mapping System • • • The smoke outlines are produced manually, primarily utilizing

Hazard Mapping System • • • The smoke outlines are produced manually, primarily utilizing animated visible band satellite imagery. The locations of fires that are producing smoke emissions that can be detected in the satellite imagery are incorporated into a special HMS file that only denotes fires that are producing smoke emissions. These fire locations are used as input to the HYSPLIT model.

Emissions • Fire locations from Hazard Mapping System Fire and Smoke Product (http: //www.

Emissions • Fire locations from Hazard Mapping System Fire and Smoke Product (http: //www. ssd. noaa. gov/PS/FIRE/hms. html) • The fire position data representing individual pixel hotspots that correspond to visible smoke are aggregated on a 20 km resolution grid. • Each fire location pixel is assumed to represent one km 2 and 10% of that area is assumed to be burning at any one time. • PM 2. 5 emission rate is estimated from the USFS Blue Sky (http: //www. airfire. org/bluesky) emission algorithm, which includes a fuel type data base and consumption and emissions models

HYSPLIT Mass distribution: – Horizontal: Top hat – Vertical: 3 D Particle • Number

HYSPLIT Mass distribution: – Horizontal: Top hat – Vertical: 3 D Particle • Number of lagrangian particles per hour: 500 • Produces surface to 100 m and surface to 5000 m 1 -hr average PM 2. 5 concentrations on a 15 -km resolution grid • Meteorology: WRF-NMM (AQF version) 12 km and GFS meteorology (outside the WRF-NMM domain) 1 degree. • Release height: assumed to be equal to the final buoyant plume rise height as computed using Briggs (1969), implying that the final rise is a function of the estimated fire heat release rate, the atmospheric stability, and the wind speed. • Smoke particles are assumed to have a diameter of 0. 8 mm with a density of 2 g/cc • Wet removal is much more effective than dry deposition and smoke particles in grid cells that have reported precipitation may deposit as much as 90% of their mass within a few hours

NWS distribution

NWS distribution

Results display

Results display

Statistics

Statistics

Dust forecasting system • PM 10 originated from northern Africa. • Meteorology: GFS (Global

Dust forecasting system • PM 10 originated from northern Africa. • Meteorology: GFS (Global Forecasting System) model 50 x 50 km • Daily runs HYSPLIT (forecast 24 hours) • Output and postprocessing • Web posting

Dust emissions • Emisions based on desert land use (spatial reolution 1 x 1

Dust emissions • Emisions based on desert land use (spatial reolution 1 x 1 degree) • F = 0. 01 u*4, Westphal et al. (1987) • Dust emissions only occur during dry days when the friction velocity exceeds the threshold value (0. 28 m/s for an active sand sheet). • The maximum flux permitted is 1 mg m-2 s-1.

HYSPLIT settings description • Mass distribution: – Horizontal: Top hat – Vertical: 3 D

HYSPLIT settings description • Mass distribution: – Horizontal: Top hat – Vertical: 3 D Particle • Number of lagrangian particles per hour: variable • Produces surface to 100 m and surface to 5000 m 1 -hr average PM 10 concentrations on a 100 -km resolution grid • Wet removal is much more effective than dry deposition and dust particles in grid cells that have reported precipitation may deposit as much as 90% of their mass within a few hours

Example of Saharan intrusion

Example of Saharan intrusion