AMFII AOS Installation Log
ARM Mobile Facility II Aerosol Observing System
Written by Stephen R. Springston
Practice Makes Perfect – The aerosol inlet on the new AOS units is modeled after the existing AOS units at SGP, AMFI and elsewhere. The dimensions and flow regimes are identical to allow intercomparability of measurements. However, there are differences. Made of two sections of light-weight, commercial irrigation tubing, the sampling tube requires no external tower only guy wires to the corners of the AOS. This allows the tower to be shipped internally (see the 10/10/2010 posting) and erected on site with three people from the roof of the fall-protected structure without using a crane. Here is a practice assembly at BNL used to iron out problems. A hinged base greatly facilitates assembly and makes the operation much safer.
October 3, 2010
On the Mountain - Once actually at Christie peak, three people had the tower unshipped, assembled and vertical in under an hour. The beautiful blue sky at 8000’ with the moon supervising is a stunning backdrop to the sampling tower. At the top is a Vaisala met sensor to report local wind speed/direction, temperature, humidity, barometric pressure and rain fall. Beneath the sensor is an inverted salad bowl to keep rain out of the inlet. The bowl is wrapped with a heating element to prevent ice/snow build up in winter by keeping the temperature above 5oC. The guy wires are color coded to the corners of the AOS to make assembly easier.
We were greeted by spectacular scenes of fall foliage both down in the valley and up the slopes to the next station at Thunderhead.
Just as good was the view out the front door. Perched at 8000’ the AMFII AOS is ideally suited to sample air from different parts of the atmosphere as diurnal heating raises and lowers the boundary layer. Seen here is the 20” keyboard, video, mouse unit that switches between and operates 10 of the computers in the AOS. This greatly simplifies the original installation and can accommodate new and guest instruments. One problem was noted: putting the monitor in the middle rack doesn’t work well at the beginning of the program when people are moving back and forth in the structure. Fortunately, any laptop can be set up in the structure to Remote Administration into computer. By design this arrangement allows mentors to access their instruments and data acquisition units locally and from any place in world via the internet.
October 10, 2010
Shake Down Street – Any new deployment, be it instruments, or in this case and entire new platform, has unexpected challenges. The PSAP instrument is a widely deployed model with hundreds of units in the field. The new unit for the AOS has custom written internal software to remedy subtle round-off errors identified previously. However, there are still some rough edges, literally.
The red o-rings are supposed to make an air-tight seal when this filter holder is assembled. The mating part had sharp edges that tore the o-rings after only two or three changes. A quick trip to Ace Hardware for some fine emery paper and the problem seems to be solved.
Other issues are not so easy. Sitting in the structure, some stripped screws were noted in the wall-mounted Unistrut. This strut (ironically just above the Emergency Information placard) is part of the support system that holds the inlet during transportation. So far, this is the only damage noted during transport of the AMFII AOS from Brookhaven National Laboratory to Steamboat Springs.
All instruments were transported secured to their racks with plumbing, power wiring and signal connections made back at Brookhaven. These racks are individually shock-mounted between the floor and ceiling to the AOS by cable isolators. This allowed pre-deployment testing AND greatly speeds up the on-site deployment.
October 25, 2010
Thar she snows! – When the instrument integration was done during August and September on Long Island, it was hard to keep in mind that snow was coming. Worse, there was no way to test for the conditions we expected. Fortunately many on the BNL team have experience in cold-weather deployments and the greater ARM community provided valuable advice and suggestions. Even with all that preparation, it was with some nervousness that we greeted the first snow fall.
Steamboat Springs Ski Resort (who graciously made their facilities available) begins to groom the ski runs around this time and requested we not drive. Fortunately we came equipped for snow and were glad for the opportunity to see how all the cold-weather preparations and planning would hold up. Now this was only a first dusting, but all systems passed with flying colors. The de-iced rain hat worked perfectly.
This view of the rear of the AOS shows the aft vestibule containing the air conditioners, the stainless steel pump enclosure and, at the bottom right, the emergency exit. Because ANL designed the exterior for future marine deployments, the exposed materials are stainless and powder–coated steel. On the other hand, this mentor had to depend on polypropylene, nylon and leather hiking boots for protection on the ascent. The AOS provided a warm, dry interior to catch his breath as well as protection for the operating instruments.
October 25, 2010
Gremlins were first described by WWII aircraft mechanics to account for unknown problems. This fellow, call him ‘Jack’, seemed to keep most of the gremlins at bay. Carved on site, we expect there may be some spontaneous pumpkins sprouting up next summer. He actually served a purpose. The candle lighting up Jack produced a minuscule amount of soot in the AOS interior. Since no increased signal was seen on the particle counter, we confirmed the inlet connections are leak-tight. That’s why Jack is smiling.
October 30, 2010
This is the end – Having completed set up of the AMFII AOS, the last of the BNL integration team departed Steamboat Springs. Before leaving, Mike Turner and Karen Sonntag were briefed on operation and daily tasks. The contributions of on-site personnel are crucial for successful operation.
The sky cleared enough to get all four StormVEx ground sites in a single photo. In the high resolution picture all four sampling platforms are visible.
With the road to the Christie Peak site closed to vehicle traffic, a brisk hike was needed for access. On most days, the views were spectacular. On the final day, this porcupine made his own farewell.