Tuesday, July 13, 2010

Hello, sunshine, my old friend

We woke up to an unfamiliar sight today, bright sunshine. We've been experiencing unusually cold and foggy weather in coastal Los Angeles for the past three months. Check out today's weather in Hermosa Beach, California (courtesy of Weather Underground).
More specifically, look at the solar radiation density.  See the nice, smooth curve as the sun rises and then sets?  Not a cloud in the sky all day!  (The eagle-eyed may notice that our solar radiation peaked at 1 PM daylight savings time, which is actually noon local time.)
Even at 7 PM, the view from Aviation boulevard, looking southwest towards Hermosa pier, showed no traces of the marine layer creeping inland for the night.
Contrast that with a week ago, on July 6, 2010.
Just compare the solar radiation at 11 AM PDT on July 6, 2010 and today, July 13, 2010.
It was 180 watts per square meter versus 800 watts per square meter today.  That's more than 4x the sunshine!  (Additionally, we are a week farther from the summer solstice so the sun is lower in the sky,  resulting in a lower cloud-free incident solar radiation density.)  

The global average is about 342 watts/m^2, depending upon solar activity; a graphic is shown in Blog Action Day 2009: Climate Change.

As an extra bonus, Scott B, who gets paid(!) to blog about the weather, posted an animation of the fog rolling out of the LA basin.

Here's a teaser, but go to his blog to see more here1 and here2.

Visit the CIMSS Satellite blog for this type of insightful commentary and interpretation:
In terms of the coastal fog and stratus in southern California, GOES-15 0.63 µm visible channel images (below) showed how slow these features were to burn off in some areas. In fact, a number of locations in the San Diego, California area experienced record low maximum temperatures for the date — including a daily high temperature of only 65º F at San Diego International Airport (labeled SAN on the images), which was 10 degrees below the normal high temperature (75º F) for San Diego on 06 July. It is also interesting to note that heating of the higher terrain of some of the offshore islands appeared to help initiate the earlier clearing of the marine layer stratus cloud deck.
I just love watching the channel islands perform a veil dance with the clouds.

And I want to know, how do I get Scott's paying gig?  ;-)

The sun came out for just one day, and already the hills are on fire.


  1. I am pretty happy that it is finally acting like summer here.

    Although I know the folks on the East coast would have loved our recent spate of highs in the low to mid 60s...

  2. Yep, that bright rising sun woke Phoebe up sometime before 5:30 this morning. She sang and told stories for about an hour before my alarm (already set too early!) went off.

  3. @Cloud
    The global-scale waves at mid-latitudes are just the right length so that the weather is anti-correlated on the E and W coasts.

    When we have a persistent low, they have a persistent high and vice versa. Lately, the low has been sitting over the high desert, moving as far north as Las Vegas. Last week, is was cooler in Vegas than in the mid-Atlantic states. Incredible, but that's monsoonal flow for ya.

    @the Smart Bohemian
    How cute! Did you record her songs and stories a la 'Narratives from the Crib'? I'd love to hear them.

  4. haha! we think alike. the sun is news to both of us. i totally dig your scientific layout of the appearance of the sun. in the local news feature i did, i only brought in anecdotal information. hey, i work on deadline:)
    nice to meecha a couple weeks ago. you and yours made a difference at the city council.

  5. I would record her songs and stories, if I could muster up the energy to turn on the iPhone at that hour. She is pretty darn cute.