Coal Hollow Fire PM 2.5 concentration

NOAA Twin Otter in Utah this week

The NOAA Twin Otter airplane is in Utah this week sampling air pollution in northern Utah including Cache, Salt Lake, and Utah counties. More information about the study can be found here: https://www.esrl.noaa.gov/csd/groups/csd7/measurements/2017uwfps/

This is bad...

Have you taken a look outside? You can't see much. This morning we were socked in with dense fog, plus the pollution levels are in the unhealthy range. PM 2.5 concentrations in downtown Salt Lake are over 100 micrograms/m3. That's bad.

Utah county has been quite a bit cleaner than Salt lake County, but I looks like the pollution from Salt Lake is being transported south. Winds are light from the north. This may explain the sudden spike in PM 2.5 concentrations at the Lindon air quality site.

This mornings sounding shows how strong this inversion really is. The ground is cold, below freezing, while the air temperatures in the mountains are above 10 C. Since cold air sinks, all that pollution we emit at the surface stays at the surface. 

Dirty Air: Spanish Fork catching up with Salt Lake

I like to think that air quality is Spanish Fork is cleaner than the urban metropolis of Salt Lake City, but that isn't true all the time. Here is a time series of PM 2.5 pollution in downtown Salt Lake City (purple) and Spanish Fork (red).

On January 27th, Spanish Fork air was about 20 micrograms cleaner than Salt Lake City. But Spanish Fork's pollution concentration has caught up to Salt Lake's today. Good thing we have a storm coming through Utah Friday night which will mix all this gunk out.

This data is from Purple Air. Looks like you can contact them to get a sensor at your house...http://www.purpleair.org/

Ozone Chasers

There weren't any storms to chase yesterday. Instead, we chased ozone pollution!

This summer our research group is involved in the Great Salt Lake Summer Ozone Study. The truck is equipped with and ozone monitor and a GPS.

Ozone Monitor

Truck with inlet tube sticking out the window and GPS on top of the truck.

Yesterday we we drove the truck from Ogden to Antelope Island and then to the international airport with an ozone monitor. We never encountered unhealthy levels of ozone, which is good. But ozone pollution in Salt Lake doesn't usually get to unhealthy levels until July because of it's dependence on sunlight. Later this summer we will be taking more observations. Yesterday's ozone chase was to test a route for the University of Utah Nerdmobile.

Of course, I couldn't leave Antelope Island without a bison selfie...

One of the projects I've worked on is providing HRRR sounding plots available for every hour of every day during the summer. I created this page for viewing these plots. These plots are from the HRRR analysis bufr soundings (downloaded from Penn State) and are created with this skew-T python package.

Welcome back to the prolonged inversions and poor air quality

Air quality along the Wasatch Front has been getting worse the last few days. Salt Lake City is the winter home of temperature inversions and bad air. And this is just be beginning of the season. Below are shown measurements of PM 2.5 (Particulate Matter smaller 2.5 micrometers in size).

The air is not super unhealthy yet, but the pollution concentration is increasing. You may have noticed the decreased visibility last time you tried looking at the mountains across the valley. This weekend a storm should blow all this gunk away before it gets much worse, but be prepared for more days like this and try to drive less during these inversion periods if you can.

November 19, 2014 @ 2:50 PM
Photo: kbkb

November 20, 2014 @3:30 PM
Source: WBB webcam

Above is another look at the smog today. The sun is beginning to set. The concentration of the smog actually looks worse due to the fact that we are looking in the direction of the sun. When particles scatter light, they always scatter with constructive interference in the forward direction, toward your eyes if you are looking toward the sun. This optical phenomenon makes the haze look brighter, making it seem there is more stuff in the air. But still, the air is dirty.

source: atmospheric radiation course notes