Editor’s note: Jonathan Gero, a research scientist at University of Wisconsin-Madison, sent this update on installing two AERI systems.
I just completed the second of two Atmospheric Emitted Radiance Interferometer (AERI) installations in what is shaping up to be ARM’s year of the islands.
The first was at an ARM Mobile Facility site on Ascension Island for the Layered Atlantic Smoke Interactions with Clouds, or LASIC, campaign. Ascension Island is one of the most remote places on Earth: It’s a speck of land in the tropical Atlantic, midway between South America and Africa. The nearest landmass is the equally isolated island of St. Helena, 800 miles to the south. The only practical way to get there is on one of the twice weekly Royal Air Force flights from England.
When I set foot on the island early morning on a sunny day in May, I had been traveling from the United States for two days straight to get there, but there was no time for jet lag. With limited time and resources on the island, I went to work right away to begin the installation and calibration of the AERI. I had great help from the Los Alamos National Laboratory (LANL) staff there, as well as the site technicians, who’ll have the experience of living on the island during the 17 months of the campaign.
The installation went relatively smoothly, and I had a chance to take some down time and visit the cloud forest at the summit of Green Mountain, the central peak of the island. It was surreal to ascend from the lower elevations of the island which are mostly volcanic desert, to lush green forests at high altitudes that were introduced by British botanists in the 19th century.
A mere two months later I was traveling to the middle of the Atlantic once more, this time to Graciosa Island in the Azores off the coast of Portugal, the location of the ARM Facility’s Eastern North Atlantic site. Graciosa is one of the smallest islands in the Azores, with a population of less than 5000. It has a similar end-of-the-world feel to it as Ascension, though it’s covered in lush green grass and forest, with ancient stone walls crisscrossing the island.
As this was a brand new installation for the AERI at this young site, there were some challenges to be overcome to accommodate the instrument. With the help of the LANL crew and the site technicians, however, we were able to get the AERI installed, calibrated, and taking operational data by the end of the third day.
ARM has field sites on three remote islands this year: Ascension, Graciosa, as well as Macquarie Island (between Australia and Antarctica). Getting to these sites can be difficult, but the scientific reward is great, as all of them allow us to study the atmosphere in a very pure state, away from local sources of pollution.