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Post by Babu on Mar 30, 2018 5:52:26 GMT -5
Everything related to the sun
I'm doing a test today. Since the UVR distribution in Thailand is heavily skewed towards shorter wavelengths (due to 10° SZA and 250 DU ozone), that means you need a LOT less UV radiation to burn. Thus, you cannot get as much UV radiation per day, and especially UVA is difficult to get high levels of.
This should mean that I have a lot of unoxidated melanin in my skin, due to lots of UVB radiation and relatively little UVA radiation. Thus, if I'm exposed to high levels of UVA radiation, I should get a quite high tan level. Today I'm going to test if there's moderate UVA radiation even at low sun angles such as 30°. I will be out in the sun, with bright fresh snow, from 10am to 2-3pm. If there's a a moderate level of UVA light, I should get a noticable tan. Five hours with snow all around should equal about 8-10h of effective sunshine. If there's even like 30% as much UVR at a 30° angle as at a 50° angle, it should equal like 3h of sun exposure in June here, which definitely would give a nice tan.
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Post by Babu on Mar 30, 2018 12:29:01 GMT -5
Okay, I swear there's something wrong with me. Last year I was paler than death in the end of April, yet a whole day on the bright white frozen lake facing the sun all the time did absolutely nothing. No sunburn, no tan, no color change at all. Yet today, loads of people have put up images on instagram of how they got sunburnt, and my GF's parents supposedly got sunburnt last weekend. I stayed out from 10 to 15 and of course I didn't notice a single color change. Yet in other instances I've got gingerbread brown after barely even a week of sunshine. And in the beginning of August 2015 I went to Taize in southern France and went completely without sunscreen even though I looked like this:  And I didn't even burn even though I literally wouldn't see shade from 9-15.00. By the end of the week I was more tanned than my olive-skinned Italian American friend.  I don't get my skin type. I'm obviously not darker than other people in the winter except the really pale ones, but for some reason I just don't burn like others do. Even that olive skinned Italian American seems to burn easier than I do. Also, I have got red a few times, but I've never actually felt a sunburn. Actually quite scary. Can't be good from an evolutionary standpoint if you cannot feel it when you're sunburnt. I did once feel a sunburn on my feet, but I've never felt that anytime else even when I've been pretty clearly red. |
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Post by Babu on Mar 31, 2018 4:09:21 GMT -5
You really should be wearing sunglasses if you're gonna be outside. Snow blindness is very real at this time of the year with this much white snow. I'm on a walk with my dog but forgot to put on sunglasses. Regretting it now.
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Post by Babu on Apr 2, 2018 4:23:49 GMT -5
Okay, so this thread has been a huge embarassment but I still need to follow up. Turns out I've got quite tanned now in the last three sunny days. So obviously 20-30° angles have enough UVR. Unclear obviously how much melanin producing UVB there is though. Still.
What's very odd though is that I created dots of full spectrum SPF50 on different parts of my face, but there are no pale dots there even though my face is significantly darker. Don't know what's up with that.
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Post by P London on Apr 4, 2018 4:56:20 GMT -5
We're supposedly heading into solar minimum. Brace yourself as solar minimum has been linked to colder winters for obvious reasons.
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Post by knot on Apr 4, 2018 5:08:44 GMT -5
We're supposedly heading into solar minimum. Brace yourself as solar minimum has been linked to colder winters for obvious reasons. Your recent winters may have been very cold by British standards, but our recent winters have been rather warm by tableland New South Welsh standards. The 19th Century was chock-full of severe winters and train-halting snowfalls, particularly 1836 & 1900. |
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Post by P London on Apr 4, 2018 5:14:02 GMT -5
We're supposedly heading into solar minimum. Brace yourself as solar minimum has been linked to colder winters for obvious reasons. Your recent winters may have been very cold by British standards, but our recent winters have been rather warm by tableland New South Welsh standards. The 19th Century was chock-full of severe winters and train-halting snowfalls, particularly 1836 & 1900. What's the average daytime high and average nighttime low in July in the tablelands? Odd to associate cold with Australia epecially "genuine" cold. |
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Post by knot on Apr 4, 2018 5:18:58 GMT -5
What's the average daytime high and average nighttime low in July in the tablelands? Odd to associate cold with Australia epecially "genuine" cold. Oberon averages, July (1,053 m AMSL; 33° 40' 5.52" S); –1° C / 8° C. I advise you to check the "March 2018 Summary Thread"—scroll down to my post for more detail. These averages were significantly lower during the 19th Century, as snowfalls were commonly in excess of two feet or more. |
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Post by Babu on May 15, 2018 0:53:15 GMT -5
This was yesterday. Sunrise was 03:31 but I don't know if this follows DST, so say 02:31. Sunset 21:41, which neans 20:41. The sun recorder seems unable ton record sunshine within an hour from rising and setting losing 2 hours every day.
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Post by Ariete on May 15, 2018 1:09:09 GMT -5
This was yesterday. Sunrise was 03:31 but I don't know if this follows DST, so say 02:31. Sunset 21:41, which neans 20:41. The sun recorder seems unable ton record sunshine within an hour from rising and setting losing 2 hours every day.
The sun recorder doesn't start to clock "sun hours" before the radiation reaches 120 W/m2, so some sunshine will be lost due to to the low sun angle.
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Post by Babu on May 15, 2018 1:18:07 GMT -5
This was yesterday. Sunrise was 03:31 but I don't know if this follows DST, so say 02:31. Sunset 21:41, which neans 20:41. The sun recorder seems unable ton record sunshine within an hour from rising and setting losing 2 hours every day.
The sun recorder doesn't start to clock "sun hours" before the radiation reaches 120 W/m2, so some sunshine will be lost due to to the low sun angle.
120W/m2 is supposed to be able to record sunshine at the horizon according to SMHI. |
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Post by Ariete on May 15, 2018 1:25:53 GMT -5
120W/m2 is supposed to be able to record sunshine at the horizon according to SMHI.
Yes, the recorder picks up the sunshine, but the radiation is not enough to count as a sun-minute.
Same thing here. And in London, and in Vostok. Only close to equatorial locations can catch most of the daily sunshine as actual recorded sun.
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Post by Morningrise on May 30, 2018 14:23:24 GMT -5
So I recently found the data for the Saskatoon SRC weather station which actually publishes its sunshine data, unlike Environment Canada who record it but don't publish it except for the 30 year averages for some reason. This weather station has data going back to the 1960s with 52 years of data and meets Environment Canada and World Meteorological Organization standards.
Some interesting sunshine stats for Saskatoon based on this station:
-The sunniest years on record were 2011 and 2013, both with 2685 hours of sunshine (59.9% of possible sunshine).
-The least sunny year on record was 1992, with 1964 hours of sunshine (43.8%), and it was also the only year on record to drop below 2000 hours. The 2nd least sunny year was 2004, with 2008 hours of sunshine (44.8%).
-Six of the top ten sunniest years were in the past 11 years (2011, 2013, 2015, 2008, 2007, 2017).
-Six of the ten cloudiest years were in the 1990s (1992, 1993, 1998, 1995, 1999, 1996)
-The aforementioned cloudiness in the '90s is evidently dragging the 30 year sunshine averages down, as the 52 year data has an average of 2312.7 hours compared with 2267.8 hours for the 1981-2010 period.
-The year with most days of bright sunshine was 1971 with 337 days. 2011 was in 5th place with 334 days, and 2013 was in 24th place with only 323 days.
-The year with the least days of bright sunshine was 1992 with 300 days.
Sunniest seasons:
-Winter: 1980, with 55.0% of possible sunshine
-Spring: 2015, with 68.5% of possible sunshine
-Summer: 1965, with 70.7% of possible sunshine
-Fall: 2011, with 61.7% of possible sunshine
Cloudiest seasons:
-Winter: 1983, with 24.2% of possible sunshine
-Spring: 1996, with 44.1% of possible sunshine
-Summer: 1993, with 44.9% of possible sunshine
-Fall: 1972, with 33.6% of possible sunshine
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