McMurdo Day 47: Marilyn AWS

Another weather station trip! This time, with more digging!

The AWS group brought Avi and I along to another site: Marilyn AWS, located out on the Ross Ice Shelf, south of Ross Island. Marilyn AWS is too far away to travel in a helicopter, so we went out in a Twin Otter plane.

We took a shuttle out to Willy Airfield in the morning.

The Twin Otter pilots down here work for a Canadian company, Kenn Borek Air, which won the contract to fly for USAP (possibly a 5-year contract?). The Twin Otters have skis on them, allowing the pilots to land on snow and ice -- very helpful when you want to visit a remote site in Antarctica.

The LC-130 planes, hanging out with nothing to do.

Originally, I was supposed to be based out of WAIS Divide camp, taking day trips to POLENET sites on Twin Otters. I was a little bummed that I wouldn't get to fly in a Twin Otter when our field season got cancelled, but the AWS team came to the rescue and let us tag along as extra field hands.

One of USAP's 2 Twin Otters (front) and only Basler (back).

I climbed on the plane with Avi, the AWS team (Dave and Lee), and Monty (who works with NIWC, the Naval Information Warfare Center, on weather forecasting in McMurdo). We got a safety briefing from our pilots, Jeff and Kelsey. It felt a little strange to get the typical airplane safety briefing ("emergency exits here and here, and you buckle the seat like this") on such a small plane with non-standard seats in the middle of Antarctica. But, of course, safety is first, and knowing the emergency exits is very important.

The team in the back of the Twin Otter. Cargo and survival gear is in the middle, and the pilots are through the hatch up front.

The seat-back pockets contained safety cards, vomit bags, and ear plugs (because the Twin Otter is LOUD).

About an hour flight (and a good nap) later, we landed at the AWS site. I have never landed in a plane with skis before, and it was a bumpy experience, to say the least.

Ski tracks from the Twin Otter landing.

There were two weather stations at the site: Marilyn AWS, and Monty's site. There are similar instruments on both weather stations; the NIWC group is taking over some of the AWS sites near McMurdo, and the station is a proof-of-concept to make sure their equipment worked as well as the existing equipment.

NIWC station (left) and AWS group's station (right).

The NIWC station had stopped transmitting data a while ago, and I think we found out why.... the solar panel was buried face-first in the snow. The batteries had stopped charging, and Monty measured them at 3V each, instead of the 13V they should be at. The batteries were very bloated and deformed from sitting at 3V in the cold. He swapped them all out immediately for some nice, healthy batteries.

Sad solar panel at the NIWC station.... it's having a rough day.

While Monty troubleshooted some of his other equipment, Avi and I made ourselves useful at the Marilyn AWS and dug a huge hole down to the battery box. We've had lots of practice at Castle Rock, so we were done in no time at all.

Moving the battery box out of the 6ft deep hole we dug.

I took a break after digging to make some snow angels.

My finished product. I know, I know, I made my arms go too high over my head. I've got to work on my technique.

Dave joined me. His turned out much better.

We then helped the AWS crew to extend the tower. Instead of digging everything up and raising it to the snow surface, like PASSCAL does at our sites, the AWS group can just secure another 7ft section of tower on top and slide all the instrumentation upwards. The only thing they have to raise is the battery box.

Lee and Dave adding another section to the tower.

While they secured the tower, Avi and I filled in the hole we had just dug.

All our hard work, filled back in just a few hours later.

I took another break to walk out to where the Twin Otter landed. If it weren't for the ski tracks, there would be absolutely no landmarks. It was flat white as far as I could see.

Looking back at the site and the Twin Otter.

My most quintessential Antarctic photo yet: Me in my big red with nothing but flat white snow and blue sky behind me.

Meanwhile, Dave and Lee worked on moving all the instrumentation up the tower. Everything was almost working when they encountered a weird problem with their wind bird. The wind direction sensor was reporting measurements half of what they should be (e.g. a wind direction of 90° was reported as 45°).

Dave and Lee securing the irradiance sensor (measures the power per unit area from the sun).

They ended up fixing the problem by swapping out their datalogger; it seemed that the issue was in how the data was being recorded, not in the actual sensor. After inspecting the faulty datalogger back in the lab, they suspect that the part of the circuit board where the wind speed sensor was attached got damaged with static (possibly shorting a resistor?).

Everyone is stumped about why the wind direction is reporting half the value it should be.

Before we left, Avi and I wrote "PASSCAL" in giant letters in the snow. Just to make it known that we were there and have done SOME field work this season. I think the letters will be blown away with wind in a matter of hours, but it was still fun to write.