BlueSky Daily Runs FAQ

What is the NAM meteorological model?  The National Weather Service (NWS) provides daily meteorological predictions using the North American Model (NAM).  NAM output is available at a variety of horizontal grid resolutions, time steps and time periods.  The NAM predictions are hourly for the first 36 hours, and three-hourly thereafter, going out 84 hours total.  

What is the WRF meteorological model? The Weather Research and Forecasting (WRF) model is a meteorological model that typically is run at higher spatial and temporal resolutions than the NAM. Like the NAM, it provides daily meteorological predictions which are usually hourly for a 72-hour period.

What is the CANSAC meteorological data?  The California and Nevada Smoke and Air Committee (CANSAC) provide daily meteorological predictions at a 2km resolution for a domain covering California and Nevada, and at a 6km resolution covering CA, NV, UT, AZ, and much of OR and southern ID.  The simulations are 72 hours and are made using the WRF meteorological model.

How do I know which model run to download? This depends on the location of the fire or fires in which you are interested, and how much detail you require. If your fires of interest are in California or Nevada, you will probably prefer the higher-resolution CANSAC runs, unless you are concerned about smoke impacts outside that domain. If you are concerned about long-range smoke transport, the lower-resolution NAM runs may be most useful. If your fires and smoke impact concerns are outside the CANSAC domain, and you are interested in near- to intermediate-distance effects, the higher-resolution NAM runs are more appropriate. 

How do I convert from degrees to kilometers? At a latitude of 45 degrees:  
1 degree latitude = 111 km (approximately)
1 degree longitude = 80 km (approximately)
therefore, a 0.08 degree resolution grid cell will be approximately 9 km in the N-S direction, and 6.4 km in the E-W direction.

What is SmartFire2 (SF2)?  SmartFire version 2 (SF2) provides the fire activity information for the nightly BlueSky simulations.  In a forecast mode, SF2 relies on the National Oceanic and Atmospheric Administration (NOAA) Hazard Mapping System (HMS) satellite fire detections, the infrared fire perimeters from GEOMAC, and the wildfire incident command system 209 (ICS209) reports to create a dataset of the latest information on fire activity.

What is BlueSky 3.5.1?  BlueSky version 3.5.1 is the latest version of the BlueSky Smoke Modeling Framework (as of 2/2014).

What is HYSPLIT v4.8 and v4.9?  HYSPLIT version 4.9 is the latest version of HYSPLIT and and was first implemented Summer of 2013.  HYSPLIT version 4.8 is the older version of HYSPLIT that has been running in the Framework since the inception of the Framework.  BlueSky version 3.5.1 gives the option of running either HYSPLIT v4.8 or v4.9.  

What are the HYSPLIT v4.9 particle runs?  The HYSPLIT v4.9 particle runs are simulations where HYSPLIT releases particles to simulate dispersion from a fire.  This is different from previous BlueSky runs that utilize HYSPLIT in a puff mode, where puffs are released from each fire and spread in a gaussian manner. The main difference between the two runs is that the PM2.5 concentrations from the particle runs have a more pixelated appearance, while the PM2.5 concentrations from the puff runs show a more balloon-like pattern.

 Which are better – the particle or puff runs? There is not an easy or straightforward answer to this question. Preliminary testing suggests that the particle runs could be more sensitive to orographic flows, but this may not be true in every case and is highly dependent on the resolution of the meteorological model. We are continuing to evaluate both configurations to gain a better understanding of how both particle and puff configurations perform under different conditions.

Additional details about the BlueSky v3.5.1, HYSPLIT v4.9, particle runs:  Near-surface particulate matter concentrations are output for the layer 100 meters above ground level.  Particles are removed after 24 hours in order to improve run times. These runs operate using parallel processing, 8 processors per run.

Acronyms
CANSAC = California and Nevada Smoke and AIr Committee
CONUS = Continental US
NAM = North American Model
NWS = National Weather Service