One of the lesser pleasures of living in Washington State is the "return of darkness" during the autumn. The rapid decline in solar radiation is particularly noticeable this time of year.
And it is not a little depressing for some.
To illustrate, below is the solar radiation received at the surface at a Seattle location near the University of Washington (the WSU Ag Weather site) from late June until yesterday.
You can see the steady decline over time of the sun's rays and the recent plummeting as clouds increasingly intercept the declining radiation due to the normal seasonal changes in meteorology.
Yesterday we dropped to about a quarter of the radiation of the peak in summer. Yuk.
Richland, with fewer clouds, shows a lesser decline, but it is still significant.
To better appreciate why September is the most depressing month for sun lovers, consider a plot of the average incident solar radiation in Seattle (below). The vertical red line shows today.
Wow. The sun's rays reaching the surface are RAPIDLY declining.... roughly half of the peak in late June/early July.
The situation in Richland, with fewer clouds and slightly farther south, is a bit better.
The key drivers in our loss of the warming rays of the sun include the changing sun angle (the sun is lower in the sky) and the rapid shortening of the day.
The graph below shows you the length of day (light blue) and night (black) in Seattle, with the vertical white line today. We hardly have much night in late June, but it is RAPIDLY increasing right now.
Just depressing.
By December only the southwest US and perhaps the southeast US are viable for significant solar production.
So if you are living in Washington State, time to think about the purchase of a sun lamp, and if you have the cash, a trip to a sunnier location during mid-winter. No wonder Alaska Airlines purchased Hawaiian Airlines.
The extreme seasonal variation in solar radiation in our region....both astronomical and meteorological... has a lot of implications for solar energy and a reason why solar energy is really not a viable source in our region for much of the year.
Let me illustrate with some official NREL solar energy graphics.
For July, there is plenty of solar resource for the Northwest, particularly for Oregon and easterly Washington.
September is still a viable month for solar radiation over the Columbia Basin and eastern Oregon, but things are rapidly going downhill in western Washington.
LOVING IT! I cannot wait until the long cold nights. Also, my most controversial statement to date, cannot wait for daylight saving to end!. Love that extra hour sleep in morning!. Yes I voted against doing away with it. Like the changing seasons I like the change.
ReplyDeleteWith you all the way! Cozy weather is returning, and it makes me as happy as sixteen hour days make the sunlovers in July. Bring it on!
DeleteSeasons are what .awesome Seattle summers so special.
ReplyDelete"Darkness warshed over the Dude. Darker'n a black steer's tuchus on a moonless prairie night. There was no bottom."
ReplyDeleteHaving lived and worked in the greater Phoenix-metro for a number of years, I definitely have a "sun light." The lamp may help fractionally, but I can't really discern its effectiveness. I do find this time of year through March a time when I check the weather forecast even more regularly for at least brief periods of outdoor exercising-- biking and/or hiking. "The Weather Blog" does help me keep the bigger picture in mind.
ReplyDeleteI'm with Budd (above). Most of my DNA is Scottish (Shetland Islands no less!), and the bulk of the rest is Dutch. I love the change of seasons, the coming dark, and all winter brings. Not a fan, however, of Daylight Saving time. I think it a stupid concept to begin with, and should be done away with asap. Stick with Pacific Standard year round. Better for one's health, as noted by sleep experts at UW.
ReplyDeleteYou've heard the humorous old story, I'm sure, about the old Indian chief who compared DST to a man who cuts a foot off the length of his blanket, then sews it to the other end and thinks he has a longer blanket. Whether we choose DST or ST all year round doesn't matter to me. Just pick one, and stop with the annual spring head, fall back nonsense. Lots of problems solved if we can solve that one.
DeleteBut do remember none of our clocks work on true sun (God/s) time. Noon is allegedly when the sun is at its hightest point in the sky. Once RRs came along in order for them not to run into each other we all had to have standard time.
DeleteBecause of your Scottish ancestry, you like dark weather. OK. This is an example of the identity thinking that has the world so messed up these days.
DeleteThat's just silly, JHK. My DNA is, I believe, a good part of the reason I don't suffer from Seasonal Affect Disorder. That, and the fact I was born and raised here, so any expectation of sun in order to have a good day is non-existent. That's all. I don't use my heritage to denigrate others, nor to say I'm somehow better, or deserving of special consideration.
DeleteWell it may be getting darker....but I like to know why it seems to occur so quickly...thanks for your meteorological wisdom as usual Dr. Mass
ReplyDeleteI am not a fan of hot weather, so less sun signifies more comfortable temperatures for me. I have never been bothered by the darker days here in WA. I moved her from FL over 10 years ago. Love it here!
ReplyDeleteBudd: Yes. It is ironic how the only states on standard time year round are southern states (Arizona and Hawaii.). Arguably there is plenty enough daylight in late spring and summer here in Washington, because of our northern latitude, that we don't need daylight time. Neither does Alaska, which has ridiculous time zone boundaries anyway- with summer midday in Anchorage around 2 PM. I wrote to Inslee a few years ago in favor of permanent standard time but he did not write back- probably too busy running for President at the time. And year round daylight time, which Inslee favors, would be a disaster- the little kids will be waiting for the morning school bus in the dark in December because it will be dark until almost 9 AM here. On standard time, though, even with darkness earlier in the evening the kids still come home in daylight around 3 PM. I would rather have the time change than permanent Daylight time.
ReplyDeleteAnsel, I remember well when Nixon did exactly this when advised by "experts" that this would somehow save energy costs. I had to wait for the school bus in bone - chilling temps in January, in complete and total darkness, lasting all the way until the second period started.
DeleteI remember that year well too. 1973-74 was the year when one caught the bus in the dark in the morning, but came home while still daylight as at that time, elementary school began I think by 8AM, if not a bit later. I recall getting into class with daylight breaking. I was in the 4th grade then.
DeleteWhat odd advice... waste more energy with a sunlamp and increased pollution with a wasted trip because of what?
ReplyDeleteMany people get substantial relief from SAD (seasonal affective disorder) using bright lights in winter. Doctors often prescribe them... you note is really not appropriate.
DeleteEarly February is the soggiest month of the year. Just about every lawn gets squishy. That is when I want to go south for a week or two!
ReplyDeleteLike I said probably the most controversial comment I have made. Lol. I have always dealt with the change nicely. So I am probably a rarity and self centered as I know studies do show the opposite. However, I have never slept with a clock in my room nor go to bed by a clock. Therefore, I think me being used to waking by the sun it all kinda feels the same to me? I do notice though waking up generally the "same" time I have extra time in the morning to get the fog out before going to work when fall back happens and like a holiday I look forward to that season. In response to Inslee loving it it is because DST saves energy. I don't know if this would hold true or not, but sending the masses to work and kids to school in a DST winter would probably increase energy use and increase emissions? I mean sending the masses to less energy efficient buildings turning on those lights and kicking up the heat, not to mention letting a car run and warm itself before work because there is not solar energy to warm it. Just a thought.
ReplyDeleteCheck these two locations south of Ellensburg. Relatively recent solar arrays. Why?
ReplyDelete46.974344, -120.575323
46.962868, -120479793
No wonder, that my late uncle Gene...a retired electrician who made good bucks and invested wisely...Was a "snowbird," Despite his Swedish heritage, he bought a nice single-wide trailer in a Nevada "closed gate" community, and would spend around six months there, Oct thru April or so. He did not mind our cool winters, but had that SAD thing going on...Besides, he met a few nice older ladies, who helped him pass the time in the warmer climate!
ReplyDelete