I certainly agree with what David said. Long-term measurements are the lifeblood of understanding what's happening in the Arctic. We've recorded some long-term datasets. I started doing measurements in the spring of 1999. This is the 25th anniversary of measurements of ozone and some gases and of ozone depletion. As a result of those records, we were able to see from year to year a lot of variability in the stratospheric ozone, which protects us from harmful UV. The years when we had very low ozone levels, in 2011 and 2020, were really there and visible in the record, because we had the long-term baseline.
Similarly, we're also measuring wildfire smoke. We see plumes coming up over Eureka. The fires in the Pacific northwest and B.C. in August 2017 injected record amounts of a number of different pollutants into the atmosphere. They came right over PEARL, and we had these big spikes. Again, they were very obvious compared to the baseline we'd collected over the years.
It's the same thing with aerosols, clouds and other things we're measuring. Because of COVID, which limited our access to PEARL, and funding problems, we now have gaps in some of our data records. Some of the instruments need maintenance, but we no longer have an operator on site year-round. You can't go back, right? We're never going to go back and get the measurements that we didn't get after March 2020 with some of our instruments.
We have some instruments that are still running. Some are automated, and for some we have remote control. We have some campaigns to go up and do things. We used to have an on-site operator year-round who would deal with minor issues, but right now we're not able to do that. We sadly have gaps, and we'd like to ramp back up to where we were.