Taking a long, hard look at the ozone hole

For more than 20 years, a Harvard research team has been taking QNX technology to stratospheric heights

The NASA ER-2 high-altitude
aircraft

Hey, do you remember when everyone was in a knot over the ozone hole? You know, the one over Antarctica? The one the size of Antarctica? Based on all the press it has received lately (read: not much), it is yesterday's problem. I, for one, haven’t worried about it — or even thought about it — for a good 10 years.

But here’s the thing. The ozone hole didn’t go away. And it’s not going away soon. Yes, evidence suggests that the hole will heal, but the process promises to take decades — by 2050, if we’re lucky. (Strictly speaking, the hole heals every Austral Spring, but only temporarily; it always returns the next Austral Winter. And it isn’t exactly a hole, since the ozone doesn’t disappear completely from the upper stratosphere. It does disappear from the lower stratosphere, however.)

Did I mention only one hole? Sorry to mislead you. There are, in fact, substantial ozone losses over the Arctic as well, with the loss during the winter of 2011 achieving ozone hole status.

Ozone depletion is serious stuff. It may contribute to an enormous list of problems, from crop failures to eye cataracts to skin cancer. So it’s important to do the hard science and measure its progress, along with any factors that can affect it. Otherwise, how do you argue for a cogent policy on controlling substances and industrial practices to prevent ozone depletion? And do you know whether the policies and practices you put in place are doing any good?

Problem is, measuring and analyzing ozone depletion is a long-term project that takes patience and commitment. Fortunately, the Anderson Research Group from Harvard University seems to have those qualities in spades.

Making the upgrade
The group has been operating continuously since 1979. (For context, that was the year that Philips demonstrated the first Compact Disc. Remember those?) For the first few years, the group used a balloon to carry their instruments high into the atmosphere, but with the discovery of the Antarctic ozone hole in the mid-80s, they graduated to a NASA ER-2 high-altitude aircraft, which flies as high as 21 kilometers. (If the ER-2, depicted above, looks to you like a modded U-2, you’re right.)

The team’s first QNX-based instrument,
which measured OH in the lower
stratosphere, was deployed in an ER-2.

Lots of things have changed since 1979, but for the past two decades, one thing hasn’t: the group’s use of QNX technology. It all started in 1990, when the group decided to replace their homegrown OS kernel with the QNX RTOS v2. They then upgraded to the QNX RTOS v4 in 1992, which is also when they deployed their first QNX-based system, an instrument that measured OH (hydroxyl radical) in the lower stratosphere. More recently, they migrated to the latest generation of the QNX technology, the QNX Neutrino RTOS, aka v6.

Alphanumeric soup
To measure phenomena in the stratosphere, the team created a data acquisition architecture that takes advantage of core QNX strengths, including multitasking, message passing, realtime performance, and transparent distributed networking. Flexibility is a key characteristic of this architecture, since it must support a variety of instruments that measure an alphanumeric soup of airborne radicals and reactive intermediates. These include BrO, ClO, ClONO2, ClOOCl, NO2, OH, HO2, O3, CH4, N2O, CO, and CO2, as well as water vapor, water isotopes, and total water. (Why measure water? Because its presence in the stratosphere can contribute to ozone depletion. And because the increased frequency of heavy storms, such as Hurricane Sandy, may inject more water into the stratosphere.)

Here is the full configuration of the data acquisition architecture, which includes control and acquisition programs running on a flight computer as well as display and interactive commands running on a ground support computer:



According to Norton Allen, a software engineer for the Anderson group, “From the start, we needed an OS platform that would scale with our growing requirements, and that would satisfy our demands for high reliability — sending a plane into the lower stratosphere is a costly proposition, so there’s no room for software failures. At the same time, we needed a standards-based platform that would let us write portable applications. The QNX OS has been able to deliver on all counts."

“We needed an OS platform that would scale
with our growing requirements, and that would
satisfy our demands for high reliability.”
Global scale
I’ve barely touched on the many research activities of the Anderson Research Group. To quote their website, the group “addresses global scale issues at the intersection of climate and energy using a combination of experimental and theoretical approaches drawn from the disciplines of chemistry, physics and applied mathematics.”

So if you’ve got a minute, visit the site. Who knows, you may learn something — I did.