The annual eclipse this morning was quite a treat...even here in Seattle where only 80% of the sun's disk was covered by the moon.
Viewable through a thin veil of clouds over Puget Sound country, the sun looked like a crescent moon around 9:10 AM (see a wonderful photo by my UW colleague Alex Anderson-Frey).
It was not a little eerie.
Solar radiation is measured on the top of the roof of my building and I plotted the solar radiation over time this morning (see plot below, time increases to the left). See below.
Solar radiation increased rapidly from 8 to 8:20 AM PDT (1500 to 1520 using a 24-h clock), then started to decline rapidly as the moon covered the sun!
Around 9:10-9:15 AM the solar radiation was at its weakest-- a huge drop.
And then, as the moon moved off the sun, the solar radiation rapidly increased.
But if you really want to see how dramatic the loss of solar radiation was you need to check out a loop of the visible satellite imagery (see below). Look closely and you will see the shadow of the moon move through from west to east.
Finally, the loss of solar heating was obvious in the temperature plot of the UW (shown below). The temperature rose before 8:45 AM and then declined over the next hour, subsequently rebounding around 10 AM as full sun was restored.
That's a great shot by Deena Stevens. We were lucky just southwest of Sunriver and got some nice photos too!
ReplyDeleteI was up on Blue Mountain (Olympics) during the eclipse. At 8, there was dew in the grass. At 9, the mountainside had all frosted over. Amazing.
ReplyDeleteCliff, is the Solar Radiation information generated by the detector on top of the Atmospheric Sciences building available to the public? Is there somewhere on the web I can go to look up it's output in real time? Thanks.
ReplyDeleteWe left Seattle Friday at 9 pm, driving through the night to south-central Oregon. After breaking out the map in La Pine, we drove a few hours more, setting up just southeast of Paisley on OR 31 where conditions were mostly clear to the southeast at 7 am. Being on the eastern side of a ridge with downslope flow, it looked like terrain was going to save us from weather. Hopefully, the clouds to the west of us were going to continue evaporating as they moved east.
ReplyDeleteThe eclipse started well enough at 8:05. The sky stayed clear to the southeast until the leading edge of the cirrocumulus deck started looming overhead at about 8:30. I looked up at it nervously since it was high enough to be minimally affected by terrain. A few minutes later, I made the choice to say goodbye to some new friends and try to outrun the deck to the east. Everyone else had longer setup/teardown times and opted to stay.
At first this gambit worked well. We drove pretty fast toward Lakeview but nothing crazy. The crescent Sun reappeared from the clouds. As we approached US 395, we hadn't left enough time to go toward Lakeview and take OR 140 east toward Nevada. Also, the cloud deck was worse to the south with some clearing remaining to the northeast.
We turned north on 395 and found ourselves battling the Abert Rim, a scarp sharply rising 2500 feet above Lake Abert. As annularity closed in, the Sun was largely obscured by terrain but occasionally broke through. The cloud deck also washed over us. I had my foot to the floor by this time, my wife calling out timings as the clock ticked ever closer to C2 at 9:17.
At 9:15, we found a ribbon of road that bent far enough west to reveal the Sun, with a little turnout overlooking the lake. I stood on the brakes hard enough to learn what they smelled like, and we sprang out of the car. I had two minutes to set up my binocular stand as annularity started. We enjoyed the show alone as the cloud deck varied between translucency and near-opacity. About 20 minutes after the crescent Sun reemerged, we packed up and started the long trek home. We got home 26 hours after we left and fed our animals.
Total trip mileage: 1091. Worth it? You bet. My only regret was that our final spot was treeless. One of my favorite parts of an eclipse is listening to birds as they sing their nightfall songs.
We had cloud cover here in southeasterm Washington. But I did manage to catch a quick glimpse of the sun's crescent at the point of maximum darkness, which was 80% coverage at 9:22 AM.
ReplyDeleteThe clouds were still hiding the eclipse but had thinned just enough to allow a quick sideways glance at the event. I'll guess my short look lasted about two seconds before I turned away.
At about the time of maximum darkness, a flock of blackbirds began roosting in a large tree nearby, but left once the full brightness of day returned.
Maybe it's just my imagination, but I thought I heard one of these birds ask another bird in the flock a question, "Is what we all just saw a result of climate change?"