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Totally untrue when you spend time reading articles from the 1930's and 40's. Sunshine hours were important for agricultural reasons from what I gathered. They took it pretty seriously in the 1930's. Don't you think that carried over into the 50's. I think as we got close to the 21st century sunshine measurement fell out of fashion and solar radiation became more important. Today I had a work meeting in Atlantic City. The skies were totally clear on that barrier island by the ocean. As soon as I got around 3 or 4 miles inland the clouds built up and the sky was much more pt cloudy with cloudy and sunny periods. I'll bet that is why there is a diff between Blue Hill, MA at 12 miles inland and Logan airport sitting right on Boston Harbor.
I was talking about the present, not the 30s, 40s or 50s!
Not disputing Arizona. But US sources themselves have downplayed the importance of measuring sunshine (as quoted in an announcement reproduced on this forum some while back).
If you asked any international expert on sunshine measurement whether they thought quoted US values were properly comparable to most other countries' ones, you would very likely get equivocation at best.
New Mexico is very sunny, so is Utah, Nevada, Colorado, and western Texas. I'm sure those areas match or exceed Lisbon.
RW has a point, but I think we need to look at it another way. From my research, the US methodology, from way back, was to try to capture the amount of sunshine from dawn to dusk. That is why they added LSC to the numbers from the thermometric system. When they switched methods in the 50's, I believe in order to keep the historical record intact they tried to capture that roughly extra hour of sun per day that C-S did not capture. C-S captured "bright sunshine" basically about a half hour after sunrise and a half hour before sunset. So, a more accurate comparison may be upping the numbers from outside the US based on a LSC number. I doubt very much that if you added all the clear mornings and evenings in London it would add up to adding an extra 250 hours to their record. More likely 100 hours. A city that had 365 clear days a year would 365 hours obviously. A rough number could be arrived at by looking at how many cloudy days per year a city had, and then maybe taking some percentage of the pt cloudy days. So, how many cities in the world RW do you think would have say 300 clear days a year? I just doubt most cities would add 250 hours based on their morning and evening sunshine. I spent 10 days(September) in Barcelona one year and I remember two distinct days that were overcast the whole day and rain. I just don't think it accurate to lop off 250 hours from every US city. Not very scientific imo and of course climatologists would most likely scorn that approach.
This issue of comparability is going to remain largely in the realm of speculation until some universal standard actually gets adopted. In the meantime I do NOT think youy've necessarily answered the US-Canada issue.
Part of the comments I once had from Philip Eden: "KZ records more than CS on days of weak sunshine (i.e. sun filtered through cirrostratus or high altostratus, or, sometimes, translucent altocumulus) ... sometimes by as much as 100% when the threshold for card-burning is marginal".
"KZ" is a flavour of electronic measurement. Given that Canada, the UK (though now in a conversion exercise), Australia and New Zealand (in partial conversion) at least are card-burning C-S methods, factors like the above need to be allowed for. I don't care wheher one subtracts from the US and possibly other countries using electronic methods, or adds to thier counterparts - I'm interested in the relativity.
But to repeat - we could pointlessly debate this till kingdom come - back to my first paragraph.
This issue of comparability is going to remain largely in the realm of speculation until some universal standard actually gets adopted. In the meantime I do NOT think youy've necessarily answered the US-Canada issue.
Part of the comments I once had from Philip Eden: "KZ records more than CS on days of weak sunshine (i.e. sun filtered through cirrostratus or high altostratus, or, sometimes, translucent altocumulus) ... sometimes by as much as 100% when the threshold for card-burning is marginal".
"KZ" is a flavour of electronic measurement. Given that Canada, the UK (though now in a conversion exercise), Australia and New Zealand (in partial conversion) at least are card-burning C-S methods, factors like the above need to be allowed for. I don't care wheher one subtracts from the US and possibly other countries using electronic methods, or adds to thier counterparts - I'm interested in the relativity.
But to repeat - we could pointlessly debate this till kingdom come - back to my first paragraph.
From my understanding Canada, like the US, has dropped direct sunshine hour measurement and are now measuring solar irradiance. The US NOAA website explained that you can use the solar radiation to compute the sun hours, but they are not going to count it anymore and will just list the solar radiation. Using the 120 Watts threshold one can calculate bright sunshine. I'm wondering how many countries will continue to count actual sunshine hours and switch to just solar radiation. What really is the use of sun hours to the average Joe reading the weather report in the morning. All he really cares is what the forecast for the day is and not how many sun hours the day before got, lol. Solar radiation on the other hand is critical for solar energy systems, even on the roof of a house.
What's the use of sunshine measurements? For one to tell how sunny or cloudy a place usually is. As far as "Average Joe" weather goes, it doesn't get more basic than that. I'd further question the entire relevance of average Joes, since that's all that people seem to be concerned about nowadays, in contrast to being concerned about the best weather statistics. In fact it seems like better and more comprehensive weather statistics were kept in decades past. There are a lot of very detailed tables and maps of a wide variety of stats that were made in the 1970's through the early 1990's, but I've seen very few, if any statistics of equal quality today. Case in point for the dumbing-down of weather is the USDA hardiness zone maps. The 1990 map featured all of North America, and one could see how U.S., Canadian, and Mexican hardiness zones tied into one another and one could get the whole picture, but the 2012 map just has the U.S. and only in degrees Fahrenheit, though I admit the detail is better .
US sunshine hours stats great for comparing one US place to another, no problem.
Where it becomes a problem is when comparing a US place to places in another countries.
US readings for sunshine hours tend to be slightly high.
For US/Canada best illustrate this...
Toronto 2038 hrs
Buffalo 2205 hrs (Toronto has less precip, in reality is slightly sunnier than Buffalo)
Windsor 2265 hrs
Detroit 2435 hrs (Windsor is across the river from Detroit!)
IMO US sunshine hrs avg approx 200 hrs higher
Northern europe is considerably cloudier than the US and I think most will agree with that.
When I visit places like the UK, I definitely notice. Even Germany and northern France.
Southern europe it's is a different story. Winters are still dull but
summers are very sunny. Spain, southern Italy, Greece are quite sunny.
US desert southwest is in a different league, Arizona and New Mexico, along with parts of California, Nevada, and west Texas are extremely sunny.
Most of the western US is sunny, both Denver and Salt Lake City average near 70%
of possible sunshine.
US sunshine hours stats great for comparing one US place to another, no problem.
Where it becomes a problem is when comparing a US place to places in another countries.
US readings for sunshine hours tend to be slightly high.
For US/Canada best illustrate this...
Toronto 2038 hrs
Buffalo 2205 hrs (Toronto has less precip, in reality is slightly sunnier than Buffalo)
Windsor 2265 hrsc
Detroit 2435 hrs (Windsor is across the river from Detroit!)
IMO US sunshine hrs avg approx 200 hrs higher
Northern europe is considerably cloudier than the US and I think most will agree with that.
When I visit places like the UK, I definitely notice. Even Germany and northern France.
Southern europe it's is a different story. Winters are still dull but
summers are very sunny. Spain, southern Italy, Greece are quite sunny.
US desert southwest is in a different league, Arizona and New Mexico, along with parts of California, Nevada, and west Texas are extremely sunny.
Most of the western US is sunny, both Denver and Salt Lake City average near 70%
of possible sunshine.
Remember, the US system was trying to capture "sunshine hours", while S-C captured "bright sunshine". It was interesting reading that in the paper from the 30's. They specifically noted the difference. There aren't any low sun correction factors added to Canadian hours.
Also, I would caution against using rainfall as an indicator. Philadelphia gets more rain than Pittsburgh, yet for sure it is sunnier here, not so much in summer more winter. You can find other examples of this, the main one being the UK. The rainfall there is not nearly as high as ours, yet the UK is much duller.
I still don't think we can just lop off hundreds of hours from US cities and maintain credibility.
Do you think that Pittsburgh, PA is as cloudy as southern England? Pittsburgh would have about 1800 hours if you lop off 200 from the US numbers. Columbus, OH would have a hundred less than Toronto and Montreal. You really think Montreal is sunnier than central Ohio? I know it is anecdotal, but I've visited Pittsburgh quite a few times and Toronto a few times. I really doubt Pittsburgh gets 200 less hours than Toronto based on my visits. It is hard to notice a sunshine diff between Pittsburgh and Philly during the summer.
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