The curse of cloudiness and climate change

[DHEB]

Cheers!

Perhaps as most of you in northern Europe, we had a dismal warm and cloudy winter here in Sweden. It has been so bad that it has prompted me to have a look at the data and consider if there is something to do with climate change.

I got cloudiness data from the Swedish Meteorological and Hydrological Institute. They have data from 1961 to 2016, but unfortunately only for daytime. With caveats for this, and for some quality issues before 1980, I found that cloudiness is indeed increasing, and that the number of clear days is decreasing even more.

Obviously I do not find this amusing. It is nevertheless consistent with the expected impact of a warmer climate on an oceanic climate like ours.

Has anyone done a similar analysis for other places? I would be happy to see your results.

Cheers and clear skies!

 

You find the complete story is in my astroblog, Epistulae Atronomicae.

 

 

 

 

[JoeP]

Very interesting. I wonder whether there are places for which clear skies are becoming more frequent? I might see what results I get for other countries if I get a few free hours next weekend.

[xtreemchaos]

very interesting, I had a good year last year here in south wales uk, I caught 218 solar disc days, but this year so far I'm 9 solar disc behind where i was on the same date last year, but just about everybody ive talked to thinks last year was bad for sun.  thanks for posting.charl.

[DHEB]

3 minutes ago, JoeP said:

Very interesting. I wonder whether there are places for which clear skies are becoming more frequent? I might see what results I get for other countries if I get a few free hours next weekend.

Thanks for your comments. Indeed, think of southern California, USA. They got a huge drought. Persistent weather patterns may be to blame in both cases.

[DHEB]

2 minutes ago, xtreemchaos said:

very interesting, I had a good year last year here in south wales uk, I caught 218 solar disc days, but this year so far I'm 9 solar disc behind where i was on the same date last year, but just about everybody ive talked to thinks last year was bad for sun.  thanks for posting.charl.

Thanks for your comment. Of course things are different in different regions. here at least, the Sun makes a lot of difference, dispelling the clouds. Unfortunately, summer here is too bright for nighttime astronomy. May be I also will have to switch to solar. Cheers.

[xtreemchaos]

you should take up Solar, the earth is the perfect place to watch a wonderfull star in action. charl.

[Knight of Clear Skies]

It's what we'd expect to see in a warming world, higher rates of evaporation and more moisture in the air. On the other hand if weather patterns change it's a bit of a lottery what will happen at a specific location.

Another factor at play is the increase in air travel since the 1970s, more contrails and sooty particles up there which encourage cloud nucleation.

[Gina]

Solar definitely seems a better option than night time imaging.  I've done white solar imaging in the past and have a Baader film filter but selling some kit and buying a narrowband scope is looking like a good option.  With my latest higher resolution astro camera I should be able to get better images.

[ronin]

16 hours ago, Cinco Sauces said:

Thanks for your comments. Indeed, think of southern California, USA. They got a huge drought. Persistent weather patterns may be to blame in both cases.

May have broke at least a bit.

Over on CN someone in sourthern CA was going to a clubs annual Messier Marathon, several months of drought but that night it rained and rained a lot. See astronomy has some practical uses.

[Joel Shepherd]

I've been pondering this myself. Seattle historically is near the bottom for major US cities in terms of clear skies in winter, but last winter was distinctly poor and this winter has been brutal: by virtually every objective measure, the worst in over 30 years. I can count the number of passably clear nights we've had since early October on two hands, with fingers to spare. It's been simply awful.

One theory I've heard is that as the Arctic has warmed, the closer balance of temperatures between (in our case) the Pacific and the Arctic means that the jet stream isn't moving around so much. Once it settles in to, for example, blowing moisture from the north Pacific over our Pacific northwest, it stays settled in for weeks or months on end. There aren't the normal temperature differentials to shift it around. I know little about meteorology, so perhaps that's bunk, but at the moment I'd buy it. We've had a virtually continuous stream of thick cloud and moisture flooding over us for six months now, with no real end in sight. It is not normal -- normal is lots of cloud and drizzle, but at least one break of a few days of clear weather each month -- and the thought that this might be the new normal is deeply depressing to me. And not just because the sun has been such a rare visitor. It's probably too early to say whether it is related to climate change but it is alarming.

[Knight of Clear Skies]

3 hours ago, Joel Shepherd said:

One theory I've heard is that as the Arctic has warmed, the closer balance of temperatures between (in our case) the Pacific and the Arctic means that the jet stream isn't moving around so much. Once it settles in to, for example, blowing moisture from the north Pacific over our Pacific northwest, it stays settled in for weeks or months on end. There aren't the normal temperature differentials to shift it around. I know little about meteorology, so perhaps that's bunk, but at the moment I'd buy it.

Yes, there is an article on the Washington Post that does a good job of explaining this, the effect on the jetstream is an active area of research.

[DHEB]

Just to contribute to this discussion, I wanted to post references to two scientific articles that identify links between a warmer world and increased cloudiness in Canada:

McGuffie, K., and A. Henderson‐Sellers. “Is Canadian cloudiness increasing?.” Atmosphere-ocean 26.4 (1988): 608-633. See article here.

Milewska, Ewa J. “Baseline cloudiness trends in Canada 1953–2002.” Atmosphere-Ocean 42.4 (2004): 267-280. See article here.

 

Cheers

/H.

[recceranger]

Of course with increasing precipitation in the earths atmosphere you will gradually get an increase in atmospheric pressure.  This may bring stronger wind speeds etc.  All very Venus like!??

[DHEB]

4 hours ago, recceranger said:

Of course with increasing precipitation in the earths atmosphere you will gradually get an increase in atmospheric pressure.  This may bring stronger wind speeds etc.  All very Venus like!??

I am not sure I follow your reasoning. In any case, more heat and clouds does indeed feel a bit venusian.

[CSM]

Correlation is not cause.  But the only new type of cloud which has appeared since the jet age is the contrail.  And IF there really has been an increase in cloudiness then I would bet on those clouds being the cause.  They certainly seem to have an effect on the diurnal temperatures as was seen after 9/11.  See http://www.greenmedinfo.com/blog/artificial-weather-revealed-post-9-11-flight-groundings

for more information on that.  I certainly could see the effect of contrails recently.  Ok for the Moon but not for Jupiter.

[cotterless45]

The cause is very inaccurate weather forecasts . If I took notice of the varying prophecies, I'd take up model trains and drinking,

cheers ! Nick.

[recceranger]

On 14/04/2017 at 18:36, Cinco Sauces said:

I am not sure I follow your reasoning. In any case, more heat and clouds does indeed feel a bit venusian.

No reasoning old chap, this isn't an academic chat room for discussion and debate, or so I'm told.  But I feel free to try and lighten the mood, especially when it comes to such a serious subject!

???

[Dave In Vermont]

As I think about what the weather-patterns are showing, I've quit wondering and simply accept we have global-changes to gaze upon as being causitive for it. It's as plain as the proverbial nose on one's face. But there is another few words I seldom hear being used - which scientists would understand - "Exponential Climb."

This infers that while people in the main-stream see a graph showing the linear changes, the 'exponential-climb' is seldom addressed. It means that there is a growth-factor that doesn't go upwards in a step-by-step fashion - it goes upward at a steep upward curve which shows doubling and even tripling in shorter periods of time. And from this we get the concept of what is meant by "tipping-point."

Where the degree of the rate is one where there is a 'point-of-no-return.'

Are we past this point of no return? That is the key question to be addressed. And doing proactive measures to safeguard from the effects - rather than simply not burning more coal & petroleum. Look to the Netherlands - they are building higher and stronger sea-walls. And having to tax the population upwards in yet another exponential fashion to pay for this.

That's what I mean by 'progressive.'

Think preactively,

Dave