Wednesday, November 15, 2017

Low Solar Radiation: Is That Why You are Depressed?

I can't tell you how many folks have emailed me or complained in person about what they perceive as a sudden turn to darkness.  They feel depressed, tired and anxious.  Daytime light helps maintain our circadian rhythms and a number of people suffer from Seasonal Affective Disorder (SAD) when the days grow short and clouds fill the sky.

So what is the truth?  How bad has it gotten?  Let's check. 

Here is the solar radiation reaching the surface in Seattle from the wonderful WSU AgWeaherNet collection of stations over the past six months (check below).   During June and July, some days had nearly 30 MegaJoules per square meter (a Joule is a unit of energy), and even cloudy days had about 15.  But recently, we have had days with 3-4 MegaJoules....way, way lower.   And the last few days, had no real spike upward in radiation to provide relief. 


Folks are right...it HAS been dark.   Part of the problem is, of course, the turn towards more clouds the last few weeks.   But, in addition, the number of hours of daylight has progressively dropped, something shown by the figure below (the vertical white line indicates today).   We have rapidly lost daytime hours the past few months and we are close to hitting bottom.


The recent switch to daylight savings time makes it even worse, with our commute home now in darkness.

The air even feels different, with biting cool, dampness that Seattle residents fear.   Here is the plot of relative humidity for the past 6 months at Seattle.  During the past month, relative humidity has jumped to around 80-90%, resulting in not only a feeling of dampness, but a loss of visibility due to fog and water-absorptive particles in the atmosphere.

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Very dark, clouds, humid, and cool---enough to scare off many Californians, and certainly able to explain the down feelings some folks have experienced during the past week.

24 comments:

bridog said...

With every passing day it gets closer and closer to the best time of the year, where it's cool enough at night to ensure healthy, unbroken sleep, and the light throughout the day is soft and subtle, preventing migranes and the tension that comes from endless squinting. This year has also seen some normal autumnal rains (our cumulative rain for the past 12wk is within 0.5" normal), washing away all the particulates and leaving us with a clean-smelling city.

Low solar radiation! Indeed, it is why we're finally getting over our summer depression.

John said...

Just head north to see the sun this November.Yakutat Alaska has already had 11(!) clear days this month,with less than 2% of their normal November precip.Juneau's had more sunny days than normal,too.

John K. said...

bridog - I agree completely. The soft light and cool temps make for easy living. Darting around on hot summer days trying to stay out of the burning sun is unpleasant and exhausting (and unhealthy).

joe mama said...

cool enough at night? what the hell? are you sleeping outside in 40 degree weather? are the high 50s really that oppressive in the summer? have you ever heard of sunglasses?

John Marshall said...

When I lived very briefly in the Danish high arctic, people had these very bright light panels they set on the table that kind of wrapped around their faces. The story was that ten minutes or so of very intense light (4000 to 5000K that filled your entire field of view) would fool the body and avoid SAD, even in the perpetual darkness of the arctic winter. The Danes swore they worked wonders.

Might be worth a try in Seattle. I'm sure such things are still sold.

Shelly D Carpenter said...

Note: we did not switch TO DST but returned to standard time. This allows more light in the morning hours and less in the evenings.

Eric Blair said...

I look at it this way - for the majority of my life, when it was winter and bright sunshine was out, it meant sub - zero temperatures. Try going out in that stuff, year after year.

Sean Mooney said...

I’m a huge supporter of DST all the time. Either way, you only have to go to east of the mountains to find sun most of the time!

Dan said...

Thousands of people move to our region each year, who have heard about the rain but given no thought to the months of unrelenting dark we experience each winter.

I count upon this time of year to inspire at least some of them to break their leases and flee south.

Russell Cunningham said...

I love this. The darker and damper, the better! Stay away, California!!

TheBugBlog said...

I hate summer...this weather is more than ideal.

Colleen said...

As Shelly said, we didn't switch to Daylight Savings Time, but the return to standard time is particularly noticeable here. No matter how many decades you've put in, the "sudden" darkness at 4:30 seems, well, sudden.

Gotta laugh at the comments above from those who are apparently sweltering in 55 nighttime temps and running in fear from sunlight. Please. lol

Molly said...

Though I agree there's something somber about the chilly dark, I still find it much easier to live with than, say, the past summer: parched, glaring, hot, smoky, and with a light ash falling from the sky. THAT was far more apocalyptic than a regular old winter.

But I think the swiftness of the change is part of what feels unsettling. The change here in weather between early September and early November is probably the most dramatic of the year, bigger than in any other two-month span. (Is this true, Cliff?)

Anisa Redmond said...

You took the words right out of my mouth.

Anisa Redmond said...

It's true to me! I feel it EVERY year.
-native lifer PNW Washington girl

Tommy Matala said...

Not scary enough to keep ALL of the Californians out, unfortunately!!

John K. said...

Dan - it is so true. "But, but, the weather here isn't like it was in California. What's up with that?" It's hilarious.

John McBride said...

Cliff, I'm one of those who almost relishes the darkness, but I like the data nevertheless. I'm curious to learn if these graphs are available to mere amateurs like me and whether there are such graphs with "averages" exhibited so one can see how current compares to past. Thanks.

Mark Henderson said...

This is the time of year I can enjoy being outdoors without the heat and bright sunlight of the summer. I vacation this time of year because I can enjoy the outdoors.

My SAD is the reverse variety. I get depressed in July and August when the outside world is unpleasant and feels hostile. I just want to hide indoors during the summer. The bright light and heat of summer makes me feel physically ill.

I moved to the Pacific NW 30 years ago. For 9 out of 12 months the weather is mostly to my taste. I like it here.

Foo said...

This is also the time of year when I see tons of people walking around in the rain wearing very non-waterproof kinds of clothing - shirtsleeves, sponge-like cotton hoodies, sneakers, etc.. They're also usually trying a bit too hard to pretend that they don't notice and/or aren't bothered.

I own a Guy Cotten raincoat that's popular with fishermen and maritime workers in the north of France. It's waterproof, comfortable, visible to drivers and virtually indestructible.

It also provokes some weird but amusing responses from the "it ain't raining" crowd - most of whom apparently have side gigs working for the Fashion Police.

A great example from earlier this week - with two bro-grammer types wearing standard-issue blue hoodies. Most of the day had already been a series of brief but torrential downpours

Bro-grammer 1 (with friend): Check it out! It's the Gordon's fisherman!
BG2: Har har.

I must have a decent balance in my karma account. Maybe 30 seconds after the last "har," the sky opens up, and then a cold downdraft adds a bunch of wind-driven hail to the weather mix. I was on the phone during all of this, and except for having to talk a bit louder, I simply carried on. So did they, which was hilarious since they now looked like drowned rats, they both had hail in their hair, and their shoes were going to make sloshing noises when they got back to work.

I don't understand the mindset and doubt I ever will, but it sure delivers more than its share of Schadenfreude this time of year.

John Marshall said...

I think the Fall change, which I agree feels far more dramatic than Spring, is the combination of shortening days, dramatically increasing heavy clouds and rain (and wind!) and then the abrupt return to standard time. That usually follows a very nice September and early October which fool us into hanging onto summer, at least psychologically. And then November lands on us like a ton of bricks.

November has always been my least favorite month in the PNW for those reasons. But by December, I'm used to it and it's no big deal.

If I got to remove a month from the calendar (along with its weather), it would DEFINITELY be November. Good news is that we're more than halfway through it already.

Karen Grooms said...

Foo! Thank you for a Saturday morning giggle. Never heard the term bro-grammer (age & living on the "other" other side will do that), and your writing is spot-on. You should expand this and submit to those local mags!

TRW Joe said...

Year-round Pac. Daylight Time would be the solution for the 4 months, Nov. - Feb........
Stop the jolt of clock-switching twice a year and enjoy the later sunsets all 12 months!!!!!

By the way, people say it's hazardous for school children having to go to school in the dark or near-dark. But according to the Facebook group, 'STOP the clock change', communities that have adopted year-round DST say "...it is more dangerous to have the darkness in the later afternoon when kids come home at so many different times. Children are on the roads as pedestrians between 3 and 6 pm due to after school sports and activities.. In the morning drivers are aware that kids are going to school and catching buses mostly at the same time of the day. Also more crime happens in the afternoon darkness than the morning darkness."

Ansel said...

Yes, I agree with Cliff, this time of year is tough- feels like someone dropped a box over my head.

But from the blog I see we definitely fall into two camps, the winter lovers and the summer lovers. I fall into the latter camp (although I also very much like spring). There are just so many more sports of which you can partake. Some, like swimming, are no way enjoyable for the next few months. The only part of summer I don't like is (in the mountains) the bugs. Last summer's smoke I didn't like, but that was an exceptional case. Though an occasional rain during summer would help the garden. Well, the climate's not perfect.