OC Weekly

Summer Guide

June Gloom Boom

It’s getting hot in here . . . wait, no it isn’t

By NICK SCHOU

Thursday, June 22, 2006 - 1:00 am

Sea breeze on steroids. Photo by Tenaya Hills

With all the talk about global warming, you’d think that summer in Southern California would be hotter than ever. But anyone who lives within 10 miles of the ocean knows that every summer brings “June Gloom” and its incessant, miserable gray clouds that blow in from the Pacific and stick around until late in the afternoon (and which, despite their name, often arrive in April or May and last until July or August). The crappy weather means that summer usually lasts from late August until early October, which makes no sense. We asked Charlie Zender, an associate professor of earth systems science at UC Irvine, for some answers.



OC Weekly: What is June Gloom?

Charlie Zender: It’s part of the natural cycle that affects Southern California around the Catalinas every year. It’s fairly predictable and fits a pattern driven by a combination of ocean, atmospheric and land interaction. If you look at the globe from outer space, Southern California is clear and desert-like, but extending off the coast to Hawaii is a constant deck of stratospheric clouds. For much of the year there is a deck of stratocumulus, and during May and June, the winds and ocean circulation undergo a rearrangement that causes those clouds to intensify and be drawn over the land during the morning, usually burning off in the afternoon.

Where else on the planet does this happen?

There are three other places around the world that have these extensive stratocumulus decks: Peru, Namibia, along the Skeleton Coast, and off the West Coast of Australia. They are all arid areas. The key thing for Southern California is that our coast doesn’t really go from North to South. It goes from North-West to South-East, and in May and June, the wind blows straight along the coast. This intensifies upwelling of cold water along the coast: the surface cools down, it intensifies the marine layer. Meanwhile, over the land here in Orange County during the summer, we are warming up because the sun is directly overhead, the desert is heating up, and daytime highs are increasing. The desert regions generate a huge thermal, which sucks cold marine air in to replace the air that is rising. The power for the sea breeze is that summertime heat cooking the desert, and you get a sea breeze on steroids in the summer that brings in a lot of clouds.

How will global warming affect summer weather in Orange County?

We aren’t sure, but we have predictions consistent with all the observations so far. In the long run, in the next few decades, the offshore Pacific Ocean will probably get colder off the coast. This isn’t part of global warming: it’s part of a natural cycle. And the temperature will only go down by less than a degree. You’re not going to see huge icebergs bumping into Catalina Island. But the effect of that is that it increases the change in temperature from the ocean to the land. If you strengthen that sea breeze conveyor belt, you can expect the June Gloom to penetrate deeper and last longer. Global warming could actually cause June Gloom to intensify even more. If both ocean and desert temperatures go up, there’s no net increase in June Gloom, but with global warming, you increase temperatures over land more than over the ocean. It takes much longer to warm up the ocean. There is no disagreement that the land will warm more than the ocean. That will speed up the merry-go-round of the sea breeze.

Are you sure global warming is real? The Bush administration isn’t so sure.

Global climate change is one of the saddest aspects of industrialization. You see all this great improvement in quality of life, and everyone wants that, and the bottom line is we can’t currently industrialize and energize economies without fossil fuels. But there is no legitimate scientific dispute with the fact that greenhouse gases warm the planet. It is increasingly clear that without any compunction for future generations, we are going to blow through the available oil and inexorably damage the planet. You can already see the effect of this on tree frogs and polar bears. But I’m glad about the fact that the so-called debate about whether global warming is real has died down. People that just want to be provocative and debate global warming are quieting down, and now we can at least have a discussion about what we can do about global warming. The good news is that it turns out that you can preserve many of the services the climate provides by just reducing the rate of burning all the fossil fuels. It has important consequences for preserving the ocean cycles we have. I think we are closer to making the right decisions than we were 10 years ago.

Forget species extinction. Let’s talk about summer. Are you saying that global warming could actually make our summers colder, cloudier and crappier than they already are?

Yes, but we’ll be glad about that because we will feel the heat much less than areas further inland, like Bakersfield or the Inland Empire, which will see very large temperature increases over the coming decades. And you can save some money on sunscreen. There’s always a silver lining.