It’s been a very busy summer, there hasn’t been a lot of time for blog posts!
In early August myself and my USGS colleagues John Crusius and Andrew Schroth flew to Middleton Island to install a dust collector. You might recall from my snust posts that we’re very interested in the chemical composition of the dust that is transported out of the Copper River (and elsewhere) during autumn and winter wind storms, and Middleton is often right in the path of the dust plumes. With a grant from NASA we have bought a dust collector that we will have stationed out there for the next three years.
Two dust events in November 2006, one going right over Middleton, one not.
We flew into Middleton from Merrill Field in Anchorage in a Piper Navajo, it’s an 8 seat twin, and we pretty much filled it up with gear.
Rob, Andrew and John plus gear on the way in.
Here we are approaching Middleton, it’s about 5 miles long and maybe a mile wide.
Approaching Middleton.
It’s a pretty neat spot, it was the site of a DEW station (Distant Early Warning) during the cold war, and had a large air force garrison until it was decommissioned in the 60’s. Currently there’s an FAA station, a NWS weather radar, and the USGS uses some of the old air force facilities for seabird research.
The FAA station.
The ruins of the USAF station / USGS bird research site.
This was once a radome tower, and is now a seabird colony. The bird researchers are able to access the nests from inside the tower.
We unloaded the plane, and got ourselves situated at the USGS camp. There was about a dozen bird researchers working there, mostly grad students, and they took very good care of us.
Dinner at "the Chateau".
The instrument we installed is a Thermo Partisol particulates sensor, we placed it a little ways from the FAA VOR transmitter, we needed a place that has power, but is not subject to contamination from vehicle exhaust or road dust. The VOR is at the end of the road, and fit the bill pretty well. Here we are bringing the Partisol to the site.
Bringing out the Partisol
I’d like to send a huge thank you to Shane England and Allen Oskolkoff from the FAA, they were incredibly accommodating, we really couldn’t have done this without all their help.
The Partisol is theoretically weatherproof, but the weather at Middleton is so extreme (80 knot winds, sideways rain) we decided to put the Partisol inside a second (hopefully stouter) weatherproof enclosure.
Driving the anchors in.
Here Andrew is winding in an anchor, the anchors we used are basically an augur with a 1 m long shank that is supposed to be screwed into the ground. The ground turned out to be a bit rocky, so we wound up having to dig the top part out by hand. Pretty miserable work, luckily we had fantastic weather to do it. Once the anchors were in, we secured the enclosure to them with stainless cable and turnbuckles – that will hopefully keep it held down.
Once everything was installed, Andrew put in some filters, programmed it, and we closed everything up.
Andrew checks things out before sealing up the Partisol and the enclosure.
The Partisol has an air pump in it that runs continuously, and sucks air and particles through the sampler that’s sticking out the top of the enclosure (Shane donated the spikes to mount on top to prevent birds from nesting on it). There’s a mechanism inside to change the filters at a user specified interval. We set it to swap the filter out every week, and there’s 16 of them, so I’ll be flying back in late October/November to pick up those filters and put in some fresh ones. The filters will be shipped to Andrew to look at how much dust has accumulated on each filter, and to look at the solubility and speciation of the iron in the particles that are collected.
Everything all buttoned up, and sampling started.
The VOR tower and the partisol system (the little white box to the upper right).
