April 24, 2008
Long range transport of aerosols to the Western U.S….This time we see the power of LIDAR
What an interesting way to begin the season; things are certainly heating up on the blog. A large influx of aerosols lingers over the Western U.S (right image- source: UW MODIS today USA Composite). The AOD image (source: NOAA-UMBC GASP IDEA) is shown on the right. Also, refer to the GASP loop (same source as the MODIS AOD). You could see that the aerosol load is very intense; AOD is mostly unity in the West near the end of the animation (center image). I suspect that most of this pollution is probably from Russian fires (and also possibly Asia). Refer to recent posts (4/22/08 and 4/23/08) on the blog that initially described this long range transport event. Below is the HYSPLIT backward trajectory that indicates the pollutant source. For some weird reason I was having trouble running these trajectories 5 days backwards in time. I will likely post an updated plot as soon as I can.
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This time, lucky for us, we have access to LIDAR data local to the region. The image shown below is data from the MPLNET Monterey (36.592550° N, 121.854867° W; Elevation: 50m) site (this is yesterday’s data. Today’s LIDAR profile hasn’t been posted on the internet yet). A significant aerosol layer is present at ~5km in altitude near 18:00UTC. A less intense layer is visible close to 2.5km.
Post amended 4-25-08:
As promised I’m uploading the Monterey MPLNET LIDAR data for 4/24/08. Also, I was getting the same result when I reran the HYSPLIT trajectories.
Haze is also visible over the Northeast (see top left image). This is likely a mix of pollution from local and distant sources. Refer to the LIDAR data (4-23-08) from the GSFC MPLNET (38.992500° N, 76.839833° W Elevation: 87m) site. We can see a layer later in the day at 7km; this might be due to long range transport. Clouds, blocking our view of the surface, dominate most of the Midwest/Central United States. However, I am providing the surface air quality map from EPA AIRNow. Mostly moderate AQ persists in California and most of the eastern half of the country.
