Talk:Insolation

message: I thought the name came from INcoming SOLar radiATION; can someone check and add that if it is true?
-Rotiro
—The preceding unsigned comment was added by 24.69.197.108 (talk) 03:33, 14 December 2006 (UTC)
thread_title: etymology

message: I'm questioning the image Insolation.png. It seems inconsistent with the numbers here, on Wikipedia's solar constant article and on Wikipedia's Sunlight article. The image appears to show approx. 400 W/m2 at the top of the atmosphere whereas others have around 1360 W/m2. Whilst it could be argued that the key shows yellow to be 400+ W/m2 the lower part of the image shows much lower figures (within the upper bound of the key) for the irradiance at the surface; Wikipedia's Sunlight article suggests 1050 W/m2 whereas the image seems to suggest a maximum of 32 W/2.
That is on top of the question as to whether W/m2 is irradiance or insolation. If irradiation then the image is incorrectly labelled.
I don't know much about this topic but it seems inconsistent to me. Selfool (talk) 14:06, 6 November 2014 (UTC)
thread_title: image

message: I just reverted several months of minor edits: the article has been quite garbled since mid-February when some particularly bad editing occurred.  In particular, the lead sentence has been composed of the first half of one sentence and the second half of another, rendering it devoid of meaning.  zowie 15:41, 30 May 2006 (UTC)
replies: text: I disagree with "The word "insolation" is sometimes used to mean either." irradiance is the word for power over area (watts or Kilowatts per square meter) and insolation is the word for energy over area (watt-hours or Kilowatt-hours per square meter).  Kgrr 10:35, 19 March 2007 (UTC)

text: The amount of energy striking the edge of the atmosphere (1AU) is called the Solar constant.  Insolation is solar radiation striking Earth or another planet.  Kgrr 10:35, 19 March 2007 (UTC)
thread_title: reverted

message: How much of the 1366 watts is visible light?  Infrared? UV?
And how does the 1000 watts at the surface split up?
And, it would be good to add a graph of power vs freq spectrum...
-69.87.199.151 20:43, 7 May 2007 (UTC)
thread_title:  Visible light? 

message: There are some interesting suntan/sunburn practical questions, and it is not clear where to look for answers.  If you lie down, clearly the greatest UV etc will be at high noon (local sun time).  (Because the light intensity is maximum, and it also hits the body most directly.)  But if you are standing up, walking around etc, and wearing a hat, things get very complex.  The sunlight itself is more intense at noon, but the exposed skin surfaces are not pointed at the sun so directly.  So, perhaps in some situations the sun exposure at high noon would actually be less than some time before or after, when the sun angles in to hit the face and body more directly?-69.87.199.249 13:12, 10 May 2007 (UTC)
replies: text: You are ignoring the ozone layer and cloud cover. Worst case for sunburn (medically) is south of the tropics. The effect of the sun's azimuth on the insolation at the Earth's surface (ie the attenuation effect) is well described in the literature.  Practically speaking for a horizontal receiving surface on a cloudless day you might as well use a sine wave starting at dawn and ending at dusk. If the receiving surface is aimed at the sun at all times then it varies as sin^0.6, practically. The concept you are looking for is called the Air Mass Index. Cheers Greg Locock (talk) 22:41, 19 February 2008 (UTC)
thread_title:  Sunburn maximum? 

message: I came here looking to find the amount of sunlight reaching the surface. I have seen someone quoting 1000 W/m2, and wanted to refute this as being too much. Diagrams of an earth energy budget give 55% reaching the ground and this article give 1366 W/m2 reaching the atmosphere, so I should have been able to find here a figure approximating to 55% of 1366 W/m2. Unfortunately the whole page seems to be about what the suns transmits and the atmosphere receives, rather than about the quantity that makes it though the atmosphere.
Furthermore, my discussion was about magnifying glasses used to burn wood, as so direct and indirect insolation figures would be useful.
Since the Wikipedia Insolation article is currently about what the sun transmits, I read the following with surprise.
The radiant power is distributed across the entire electromagnetic spectrum, although most of the power is in the visible light portion of the spectrum. 
Since most sunlight is not in the visible spectrum as far as I know, I took that to be incorrect. However after absorbtion of sunlight by N2 and O2 in the atmosphere, most of the power making it down to the earth's surface might be visible. Does the sentence mean more within the visible spectrum than without? Or just more inside than within another smilarly sized band of the rest of the spectrum, and in the latter case, are these frequency bands or wavelength bands?
Since the radiation reaching the earth's surface will depend on the angle of inclination of the surface, and that will depend on latitude and season, maybe a table would be useful so someone could estimate for example heating at N 50 degrees in March.
People have argued whether figures should be energy or power. Those that argue for energy have nevertheless ended up saying energy 'per day', and that is a power figure.
So somewhere we should mention the peak power, the average power of a sunny day, average power all together, etc, and how they relate to each other. My figure for a magnifying glass burning paper for example assumes a plane perpendicular to the sun and somebody working out heating would need to account for latitude. Somebody working out sunburn would be interested in atmospheric scattering, as sunburn is worse at midday even though you can be perpendiular to the sun at twilight. The previous posters remarks demonstate my point. 
In my opinion this page omits a lot and answers very little.
I don't even think insolation is a real word. Isn't it just somebody's made up word from incoming solar radiation.
Crysta1c1ear (talk) 14:35, 9 February 2008 (UTC)
thread_title:  Spectrum and other thoughts 

message: Can anybody help me with this? I read in places solar radiation reaching the earth is around 1350 W/m2 and that most radiation is infrared absorbed by the oxygen and nitrogen in the air. And yet we also read figures like 1000 W/m2 making it down to the ground.
It appears to me that the arithmetic doesn't add up. 
What sort of figures are we talking about for high energy photons absorbed by O2 and N2 heating the thermosphere to 2500? Are the high figures that I read for incoming solar radiation really figures that include a lot of reradiation from the thermosphere etc? If there is reradiation, how do the reradiated frequencies compare with those of the original radiation? Clearly there are temperature difference, 6000K for the sun and 2500K for the thermosphere. But the quantum jumps in the atmospheric atoms might be the same for receiving energy as for emitting it. So are the retransmission frequencies the same or different. Also, is this reradiation lumped together with scattering? Logically I regard it as different.
Any comments, references, help would be welcome.
Crysta1c1ear (talk) 13:07, 22 February 2008 (UTC)
thread_title:  O2 and N2 absobtion 

message: I removed from the intro: "Sometimes, as in the text below, a long-term average intensity of incoming solar radiation will be given in units such as watts per square meter (W/m2 or W·m-2) and called insolation, with the duration (such as daily, annual, or historical) stated or only implied." It's not clear what this sentence is intended for. There is no implied duration in W/m2. A Watt is one Joule per second. If the issue is over what time period the average is taken, that should be made clearer. --agr (talk) 12:08, 19 August 2008 (UTC)
thread_title:  dubious sentence 

message: The article states that units for insolation are energy per unit area (W.hr/m2), but the text accompanying the graphics to the right of the article gives units of power per unit area (W/m2).
Most folks, like me, looking at this page want to know how much solar energy can be captured per unit area in some region.  The units kWh/kWp•y don't mean much unless you know what kWp means.  The fact that experts use it all the time does not help. Fairandbalanced (talk) 20:22, 12 October 2008 (UTC)
replies: text: The article says kWp means kilowatt peak rating. But I agree more explanation is needed. Presumably kWp is based on some assumed peak value for solar insolation Anyone know what that is?--agr (talk) 19:54, 13 October 2008 (UTC)
replies: text: Energy is power over time, so the average power per unit area over the course of a multiple year time is still power per unit area, and works out to energy per unit area over any specific period of time, such as an hour. KWp is measured under standard conditions, at such and such temperature, and such and such insolation (1000 W/m2). I think one of the other solar articles explains that. Perhaps a link could be made to it. I see that the photovoltaics article has a link to kWp. Found it. Will make a link. 199.125.109.80 (talk) 06:04, 3 November 2008 (UTC)
thread_title:  units 

message: The equation for an ellipse is
:r=\frac{a (1-\varepsilon^{2})}{1 - \varepsilon \cos(\theta - \phi)}.
but the article uses
:R_E=\frac{R_o}{1+e\cos(\theta-\varpi)}
omitting
:(1-e^{2})
The following line is completely wrong
:Nevertheless, θ = 0° is exactly the time of the vernal equinox, θ = 90° is exactly the time of the summer solstice, θ = 180° is exactly the time of the autumnal equinox and θ = 270° is exactly the time of the winter solstice.
''
By definition, the vernal equinox defines the zero angle in such a way that, for the given equation, the Earth is located at 180° at the vernal equinox. Not 0°. I know this is counter intuitive, but that really is the way it is done. Q Science (talk) 06:52, 17 December 2010 (UTC)
thread_title:  Equations 

message: where is the proof? I've been trying to find a global average of irradiance that hits the earth and the closest I could find was this: http://home.iprimus.com.au/nielsens/solrad.html . Which states (through calculation) that the average irradiance is 198 W/m^2
Can whoever put that up (without citation, I might add) please provide calculation of how they came up with that number? Thanks.
Ktonlai (talk) 01:44, 17 August 2011 (UTC)
thread_title:  Average is 250 W/m^2 ? 

message: A barometer is something that earth scientists use to measure air pressure.  — Preceding unsigned comment added by 174.130.0.72 (talk) 01:08, 21 September 2011 (UTC)
thread_title:  Barometer. 

message: "As the angle increases between the direction at a right angle to the surface and the direction of the rays of sunlight, the insolation is reduced in proportion to the cosine of the angle; "
True.
But the angle shown (illustrated) is between the SURFACE and direction of the sun's rays... where the dependency is on sine, not cosine..
Suggest showing the correct angle for illustration.  — Preceding unsigned comment added by 97.101.162.114 (talk) 00:42, 2 February 2012 (UTC)
thread_title:  OOPS 

message: Is insolation distinct from ensolation, meaning the solar energy received or absorbed?<BR>
The well used 'Ensolation' has the advantage of being less easily confused with the almost antonym 'insulation'.  (Almost as bad as we did with flammable & inflammable.  It took decades to get most professionals to use non-flammable.)<BR>Wikidity (talk) 21:45, 16 December 2013 (UTC)
thread_title:  ensolation 

message: It would be interesting to show the theoretical (or actual) curves of insolation over the days of the year, like . -- Beland (talk) 16:45, 2 October 2014 (UTC)
thread_title:  Variation over the year 

message: Just finished a ce. Are these the same? The text seems to say so. If so, then merge the two articles? Lfstevens (talk) 22:07, 2 August 2015 (UTC)
thread_title:  Insolation v solar irradiance 

message: The only source of energy for the earth's atmosphere comes from the sun which has a surface temperature of more than 10,800°F.
This energy travels through space for a distance of 93 million miles and reaches us as solar or radiant energy in the process called insulation.
This radiation from the sun is made up of three parts of rays
▪︎White light(visible rays)
▪︎Ultra violet
▪︎Infra-red rays 139.5.255.140 (talk) 14:45, 23 April 2022 (UTC)
thread_title:  Insolation