The ozone layer has been holding up

The weather pattern certainly changed in early November as we had more rain in the first two days of the month than all of October. At Cliff’s station, only 0.26 inches of rain fell last month in Coeur d’Alene, compared to a normal of 2.22 inches. For November, our average precipitation for Coeur d’Alene is 3.07 inches. As of this weekend writing, we’re about half of the way to our November normal.

More rain is expected early this week with snow in the higher mountains. According to the long-range computer models, there may be some showers later in the week. With the added moisture and occasionally dry conditions, this may also be the recipe for the formation of some potentially dense late-night and early-morning fog, especially in the lower elevations. However, as we get into the normally wet new moon lunar phase that begins Nov. 13, more Pacific storms are expected to move across the region. It’s also possible that one of these systems may be cold enough to produce some more measurable snow in the lower elevations around the middle of the month. So far, only 0.2 inches of snow has fallen at Cliff’s station for the 2023-24 season.

In the higher mountains, not much snow, if any, is being reported on the ground as of early Sunday. But, over the next several weeks, we should see some snow that may increase the chances of the ski resorts opening up around Thanksgiving. We’ll have to wait and see how these storms develop and whether they will be cold enough in the next few weeks to produce the heavier snow. Regardless, it’s shaping up to be a wetter-than-average November across much of the Inland Northwest.

Early this year, I talked about the ozone layer over Antarctica. According to a recent summary of the Scientific Assessment of Ozone Depletion, the ozone layer was progressing in a positive direction and may be mostly recovered by 2040 across most of the planet. The study also indicated that the polar regions would likely take another five to 25 years with the hole over Antarctica taking the longest to recover.

Scientists were concerned that the big underwater volcanic eruption Jan. 15, 2022, the Hunga Tonga-Hunga Ha’apai, or Tonga for short, would increase the size of the ozone hole due to the massive amounts of water injected into the atmosphere. Instead, according to an article by Phys.org, the ozone hole maintained its average size. Since 1979, satellite observations have been tracking the hole in Antarctica daily.

With such a large eruption, millions of tons of water were sent into the atmosphere in the Southern Hemisphere. With the additional liquid water, it was estimated that other naturally occurring chemicals in the atmosphere would combine and “eat away” parts of the ozone layer, which would increase the size of the hole. Instead, according to the article, it’s now believed that the water was ejected from the eruption, froze out higher and earlier resulting in less clouds and water for the chemicals to branch onto that would have increased the ozone hole.

The ozone layer typically peaks in September and, on average, reaches its maximum around the third week of September. By the summer (December, January and February), the hole would usually fill, or decrease in size. According to the latest observations, from September through the middle of October, the hole averaged approximately 8.9 million square miles, or 23.1 million square kilometers. The article states that the largest size was around 10 million square miles, roughly the size of North America. According to data from NASA, the largest measurement of the ozone hole occurred in 2000 as it was a record 11.6 million square miles.

Back in 1974, scientists argued that chlorofluorocarbons (CFCs), a chemical used for refrigeration, hairsprays and other aerosols were harming or depleting the ozone layer. This critical layer which is primarily located in Earth’s stratosphere, typically absorbs about 98 percent of the harmful ultraviolet radiation from the Sun. If the ozone layer did not exist, then scientists say that life on this planet would be unsustainable.

Australia is close to Antarctica and has one of the highest rates of skin cancer in the world. During their summer season, which can be intense, government officials will constantly issue warnings for those who are planning to stay outside for an extended period to use sunscreen, or at least try to stay out of the sun as much as possible. It’s good advice and sunscreen should be considered when venturing out in the Sun anywhere on Earth.

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Contact Randy Mann at randy@longrangeweather.com.