30 December 2013

The University of Wyoming King Air

As promised, here is just a little bit about the airplane I've been flying in during the OWLeS project!

I've mentioned in previous posts that many different types of research tools and instruments are being used in OWLeS to make measurements of the atmosphere while lake-effect snow storms are taking place. The main contribution from the University of Wyoming is our own research aircraft, the King Air. This means that the majority of the work I am doing during the project is related to the aircraft, which includes flying on it during IOPs!

The Aircraft Itself
The King Air is a small twin-engine airplane outfitted with various meteorological instrumentation and has been used in many research projects over the last 36 years. It has been all over the United States, down to the Caribbean, to Finland, and most recently to England, just to name a few locations. Most of the instruments or sensors on the airplane make fairly common measurements, like temperature, air pressure, wind speed/direction, and humidity. There are other less-common sensors that measure the size of cloud droplets and the amount of liquid water in the air.

One of the most valuable instruments on the plane is the Wyoming Cloud Radar, or the WCR. The WCR, like any weather radar, sends out a beam of radiation into the atmosphere at very small intervals (i.e. many times per second) to show where the precipitation is located and how intense it is. The WCR is actually able to send out 3 beams at once; a beam that points straight down, another that points downward but slightly toward the front of the plane, and a third that points straight up. So we can actually fly through a cloud and see what the precipitation pattern looks like, both below the plane and above. We can also use the measurements from the WCR to figure out how fast the air is moving upward or downward. Another important instrument on the King Air is the Wyoming Cloud Lidar, or WCL. It works similarly to the WCR, but instead only points straight down and measures cloud particles (i.e. water droplets or ice crystals) much smaller than precipitation.

During an OWLeS research flight, the King Air will typically fly "leg" patterns into and out of lake-effect snow bands. This is best illustrated by the photo below, but essentially all the plane is doing is flying a bunch of brief, straight paths ("legs") through the snow band, back-and-forth almost in a zig zag manner. Some of these legs are flown at different heights above the ground...for instance, some are flown above the cloud, some inside the cloud, and some below the cloud. We can usually do about 11 or 12 legs before we run low on fuel and have to go back to the airport. This keeps each flight to about 3 1/2 hours long.

King Air "lawnmower" or "ladder" flight pattern. The north-south legs are intended to transect a lake-effect snow band. Courtesy of the UCAR/EOL OWLeS online catalog.
The plane is also a national research "facility", meaning that any researcher in the United States can request to use the plane for research if they can get money for it. So why would a researcher be interested in using the King Air?

Well, an airplane obviously flies in the air, several thousand feet above the ground. It is very difficult to get meteorological measurements that high in the air using other instruments. The King Air can also fly to the storms, instead of waiting for the storms to come to it.
Most of us are used to seeing radars from our local television meteorologist, but the radars shown on TV only let us look at storms horizontally. The WCR and WCL, because they point up and down, can help us see what a storm looks like vertically. This type of data can be very important for researchers because it often helps them understand what is going on inside clouds or storms. These are just a few reasons why the King Air is considered a very important research tool in OWLeS.

The Crew
Only 4 people can fly on the King Air at once, and all of them are considered crew members. This means that no one can fly on the airplane simply as a passenger. Each person is required to fulfill some type of flight mission "duty". 

  • 1st seat (front left seat) - pilot
  • 2nd seat (front right seat) - mission/research scientist
  • 3rd seat (back right seat) - flight scientist
  • 4th seat (back left seat) - research/flight assistant
View from the 4th seat on the King Air
I don't need to explain what the pilot does. The mission/research scientist is responsible for making the scientific decisions during the flight as well as making decisions regarding changes in aircraft altitude or direction of travel. This person is usually a scientist, often one of the principle investigators on a project (i.e. professor/researcher). The flight scientist handles all of the weather sensors and instruments and makes sure they are all turned on and running smoothly. He is usually also very knowledgeable about the science side of things and typically helps the mission/research scientist make decisions. 

View from the 2nd seat on the plane
Finally, there is the 4th seat in the plane, which is where I always sit! The person in the 4th seat is responsible for helping the flight scientist by monitoring some of the instruments (usually the WCL) and keeping in contact with other scientists on the ground using a chatroom. The 4th seat is occasionally unclaimed for some flights, allowing other students the chance to experience what it's like to fly on a research mission.

I feel like I've been very fortunate to have the opportunity to be involved with the King Air during OWLeS. While I miss all the snow falling on the ground below, it is pretty cool to say that I was flying through it while it was happening. OWLeS is about to resume operations later this week, so hopefully the second half of the project will be as much fun as the first. Keep checking in for updates!

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