Pyrocumulus Clouds over California and Oregon Last week

With much of the Pacific Northwest experiencing drought conditions, fires burning in Northern California and Southern Oregon led to poor air quality conditions regionally and downwind of the fires in early August.  Pyrocumulus clouds, also known as "fire clouds",  appear as opaque white patches hovering over darker smoke in satellite imagery and form from the intense heat of the fires (similar to cumulus clouds forming over a sun-warmed ground). The MODIS satellite views below show pyrocumulus clouds near the California/Oregon border associated with the Beaver Complex Fire and Bald Fire. 

AIRS observed in near real time the rapid vertical motion associated with these pyrocumulus clouds and the injection of carbon monoxide high into the atmosphere (at least 5-6km above the surface).  Once the smoke reached this height, CO is easily transported downwind as seen in the image below where the plume extends eastward into Idaho.The Ozone Mapping and Profiler Suite (OMPS) also captured smoke emanating from these fires.  Observations of aerosols detected by OMPS can be viewed here and show the smoke plume transported to Idaho and Montana by August 3rd. 

As of August 8th, the entire region remains under a Fire Weather Watch. With droughts continuing to be a serious problem, the threat of forest fires remains high as we continue through August. 

This blog post was the combined effort of Meredith Nichols and Debra Kollonige.

How are emission sources distributed in Weld County Colorado? - HOT TOPIC during the DISCOVER-AQ/FRAPPE campaigns

Natural gas and oil wells have appeared more rapidly across Colorado in the past few years, particularly in Weld County, which is one area where the DISCOVER-AQ/FRAPPE aircrafts have been flying this past month. The C-130 aircraft, run by NCAR/NSF, detected possible well signatures in the area between Platteville and Greeley (see figure below) on July 26th, where there is a heavy population of oil and gas wells (not shown).     

The first area circled in red between Greeley and Kersey (C-130 measurements below) appears to have gas emissions from both agricultural and oil & gas sources. The C-130 measured elevated concentrations of ethane and benzene in this region, typically oil & gas signatures, but ammonium (bi-product of ammonia) also has elevated concentrations. Based on EIA's database of oil and gas wells and google imagery of farms and well pads, we discovered this area does have both sources. 

Further to the south near Gilcrest, the C-130 measured (preliminary data above) hot spot of benzene, but unlike the first area, there was no elevated ammonium just west of the town. EIA's well database places multiple wells in this area as well as a natural gas power plant, indicating a local source. On the figures above, another area to point out is just southeast of Platteville and northeast of Fort Lupton.  Elevated concentrations of nitrogen dioxide (NO2), benzene, ethane were measured by the C-130 and are most likely being emitted by oil and gas wells situated south of Platteville and multiple natural gas power plants just northeast of Fort Lupton (based on EIA's database).  

Ground measurements from NATIVE at DISCOVER-AQ Platteville site (above) between 25th-28th of July show enhanced CO, CH4, SO2 (sulfur dioxide), and NO2 on the same day (morning of), most likely from a common local source (ie. wells and power plants to the southeast).  This appears to be a common occurrence as the next morning CH4 and NO2 are again elevated and could be emissions from the operation of a nearby gas well.  The figure below is a satellite view of the Platteville site and indicates the proximity of this site to oil and gas well pads as well as the pictures below (taken by Ryan Stauffer) of a well constructed just southwest during the Gator Team's time there.   

This blog post was the combined effort of Zachary Fasnacht and Debra Kollonige.

Heavy Rainfalls Lead to Healthier Air Quality Conditions in Colorado Front Range Last Week

Smoke, most likely originating from fires in the Northwest Territory (Canada), still lingered across the north and central US on the 27th of July.  NOAA's HMS imagery places smoke from the Canadian fires extending from the Colorado Front Range to Tennessee and across much of the central US (left).  Similarly, the AIRS instrument sees high concentrations of carbon monoxide throughout this area on the 27th (right).     

NOAA HMS fire and smoke product (left) and AIRS NRT carbon monoxide at mid-troposphere (right) courtesy of Debra Kollonige.

A low pressure system entered the region on the 28th of July, which resulted in heavy rainfall over the Colorado Front Range between July 28th-31st. The High Park Precipitation Station, near Masonville, CO, slightly southwest of Fort Collins, received roughly 2.5 inches of rain in about 24 hours (top). A precipitation station in Denver recorded almost 3 inches of rain in a similar time span (bottom).  This much needed rainfall helped temporarily relieve the state of its current drought conditions and most likely caused mixing of the smoke pollution into the atmosphere, leading to cleaner air quality conditions across the Colorado Front Range.  

Data and figures courtesy of the USGS, the Colorado Real-Time Precipitation Network, and Meredith Nichols.  

Measurements from the PSU NATIVE trailer out at Platteville, Colorado, taken during the DISCOVER-AQ campaign show the drop in carbon monoxide (left) and increase in relative humidity (right) between the 28th and 31st of July (marked in red on the figures below).  

Data and figures courtesy of the PSU Gator Team and Sonya Miller of PSU.

This blog posting was the combined effort of Debra Kollonige and Meredith Nichols.

  
Update 8/6/2014 at 1:00pm:  Here's an interesting video time lapse of the clouds and rainfall in the Front Range 28-31 July.  Thanks to Meredith Nichols for finding this.