How is the Solar Constant Affected by other Universal Factors (Auto Recovered) PDF

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Investigating the Solar Constant of Earth and What Affects It? Personal code: jlg336

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Personal Engagement I have always been into Climate Change and Global Warming with a tiny bit of Astronomy. And I believe Climate change is happening, Global warming is happening and with along it comes other dangerous effect which comes along with it includes rising sea level, floods and etc. And if we do not stop it right now, we will be heading into a dangerous territory. And due to that I chose solar constant as I can relate it to rising temperature and speak how depleting ozone level and other factors can indeed affect the solar constant. This is also a relevant topic I could talk about as it also has a slight correlation with Meteorology. For university I wish to study Meteorology

The solar constant is the amount of solar radiation across all wavelengths that is incident in one second on one square meter at the mean distance of the Earth from the Sun on a plane perpendicular to the line joining the center of the Sun and the center of the Earth. For earth the average solar constant is around 1370 watts per square meter (W/m2) Solar constant is supposed to be constant but, in my opinion, there are factors which can have a minor effect on the solar constant. Such as land elevation, weather, temperature, earth’s rotation around the sun. I came across the Solar Constant in Unit 8 Energy Production. And since I wanted to revolve my IA around temperature, I chose Solar Constant as my IA topic as temperature is one of the main factors. All my IA is based around temperature because I want it also to be revolved around rising global average temperature. I am going to be carrying out this research solely around secondary data which is going to temperature data from nullschool.net (Earth:: A Global Map of Wind, Weather, and Ocean Conditions, n.d.) and using google earth for more intensive research on why there is a difference. So, I use two formulae which are the Stefan Boltzmann Law (Stefan–Boltzmann Law, n.d.) which goes along as P=σAT4 (Power=emissivity x Area x Time 4) and which then will be substituted into S=P/A (Solar Constant= Power/Area) (Solar Constant, n.d.). I will therefore be measuring the temperature of 5 different countries in different continent of an area of 250000m2 which are United States (New York), England (London), Nepal (Himalayas), Qatar (Doha), Australia (Alice Springs).

Hypothesis Three hypotheses will be used to investigate the solar constant. Which are: 1. As land elevation increase solar constant decreases 2. As albedo increases solar constant decreases 3. As ozone Dobson unit increases solar constant decreases The fist hypothesis should be correct because as when land elevation increases the temperature decreases as the there is less air above you thus the pressure decreases. As the pressure decreases, air molecules spread out further (i.e. air expands) and the temperature decreases. The second hypothesis should also be correct theoretically as when albedo increases the ability of that surface to reflect light should also increase making the surface less warm than usual. Theoretically the third hypothesis should also be correct because as ozone level increases the

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thickness of the atmosphere increases making it harder for light waves to pass through, making the solar constant decrease.

Stefan–Boltzmann law

P=σAT4 Qatar = Power =5.7

x 10-8 x 25000 x (32+273)=4.35053

Solar Constant Formula S=

Qatar=Solar Constant=

Power Area

4.35053 =1.740212 x 10−5 250000

Country

Power/W

Solar Constant/ W m−2

Qatar

4.35053

1.740212 x 10-5

Nepal

3.88741

1.554961 x 10-5

England

4.00283

Australia

4.25363

USA

3.86603

Qatar To measure the solar constant, I took a patch of 250000m2 for my area. The area was from the center of Qatar and the temperature

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was around 305.3 Kelvin. With this I got the Power as 4.35053 which I substituted into the solar constant formula which resulted in getting around 1.740212 x 10 -5 W/A. As Pic.1 shows majority of Qatar is sand with some vegetation growing towards the sides. Therefore, albedo plays a big role here. Albedo is the measure of the diffuse reflection of solar radiation out of the total solar radiation and measured on a scale from 0, corresponding to a black body that absorbs all incident radiation, to 1 (Albedo | Definition & Examples, n.d.). For Qatar, the sand is having an average albedo of 0.45-0.5. This means they reflect half of the Power from the sunlight. Another factor which can impact the solar constant is ozone level. Ozone level is a layer in the earth’s atmosphere which reduces the amount of Ultraviolet light coming from the Sun (Ozone Layer, n.d.). The higher the ozone level, the lower the solar Constant. For Qatar during the time the average ozone level was 238DU (Dobson Units) which is around average ozone thickness. This might have an effect in the Solar constant as it limits on the amount of sun rays and ultraviolet light from reaching the surface Land elevation can also affect the solar constant.

Nepal In Nepal, the average temperature is relatively cold. Due to its mountainous environment and harsh climate. The area for Nepal I chose was a mountainous region so I can identify how altitude, ozone level and since its mountainous region temperature is going to be low, therefore, how temperature can affect solar constant. The area for the location I selected is also 250000m to keep all the values fair. The temperature for this location was around 272.8 Kelvin. Thus, giving a power of 3.8874. Which then I substituted it into S=P/A which then resulted in getting a Solar Constant of 1.55496 x 10-5. This is much lower that the solar constant of Qatar and there can be many reasons on why. Firstly, the biggest and sole factor on why Nepal has a lower solar constant than Qatar is temperature. Qatar has a higher temperature.

than Nepal resulting the solar constant since temperature is in the Stefan-Boltzmann law. Ozone level can also greatly affect solar constant. During the time the data was collected Nepal had an ozone level of 263DU. This means majority of the solar waves is being blocked by the ozone layer thus reducing the amount of Solar Constant. Also, elevation of land can also affect. The region I chose had a land elevation of 7.5kilometre in height. This means that Solar Particle is going to be attenuated. This is because higher elevation means humidity is going to be greater. This further adds to the ozone layer, so this means that humidity is a further blanket the solar particle must get through. This therefore will decrease the Solar Constant overall.

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England England is in Europe. England is known for its rainy and wet atmosphere. This means that the average solar constant should be low. This can be due to its cloudy weather. In England the area I had selected had an average power of 4.00283. Therefore, the solar constant has a value of 1.601132 x 10-5. This value as we can identify is less than the solar constant in Qatar although Nepal is lower due to many reasons such as elevation and temperature. Solar constant can be affected by clouds as clouds can be extremely reflective as it is white in color therefore the albedo must be high. The most common type of clouds in England are cumulus clouds. The average albedo rate for cumulus clouds is between-0.45-0.55. A rate of 0.45-0.55 means that half of the solar radiation which surfaces the clouds are being reflected by the clouds. The ozone level of England also comes into play as it has a Dobson value of 255. This is a high value as it is higher than the ozone level in Qatar. Although lower than the ozone level in Nepal. This makes sense as the solar constant has a lower value than Nepal. The area I took also seems to have a lot of trees. Trees can generally reduce the solar constant of the area as trees are known to absorb incoming solar radiation than many other absorbers. This can also be one of the reasons this area has a low solar constant rate. But the biggest reason for the change in solar constant is the difference in temperature. The temperature for the patch of the area I selected was around 280 Kelvin.

Australia The patch of the area I selected has also has an area of around 250000. The area I chose was in the middle of Australia. Therefore, the area I chose was in the middle of the desert. Although the location was a desert, the location was mountainous. Maybe affecting the solar constant. from the table we can identify that the

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area has a solar constant of 1.701452 x10-5. The solar constant of is significantly lower than Qatar. This might be because of the type of sand in Australia. The sand in Australia has a red color which means the sand is rich in iron content. Still Australia is an anomaly in terms of albedo as white sand in Qatar is much more reflective than red sand meaning Australia should have a higher solar constant than Qatar. Although this could change due to many other factors. Australia’s red sand has a clay like feature making it absorb more solar radiation especially infrared radiation. The main other factor is the ozone level over this patch of area. During the time Australia had a Dobson unit of 258. Which is lower than Qatar’s. A Dobson unit of 258 indicates that the ozone layer is less than Australia indicating less solar radiation is piercing through this layer and more solar radiation is being absorbed by this layer.

USA The site I chose for this has a lot of buildings around it, it is positioned in New York. USA has the lowest solar constant rate this. There could be a variety of factors for this as a busy populated area should be having a high solar constant rate. Picture 4 shows a lot of buildings meaning that solar constant should be high as more building means more infrastructure such as glass. Glass can increase temperature because, the suns solar radiation travels as short wavelengths and enters inside houses and rooms in the apartment the object inside these building absorb these short wavelengths of radiation and emits heat at a longer infrared wavelength. These waves will have difficulty escaping out of the room getting it trapped inside the room or house. Thus, people will invest in air conditioning. Air conditionings will release carbon dioxide into the air. Carbon dioxide can as a blanket for global dimming. Global dimming is the blocking of the solar waves from reaching the surface of the earth and with the help of carbon dioxide it adds to the ozone level creating a further blanket. New York has a Dobson had a Dobson unit of 305. This is the thickest layer of ozone layer in the five countries chosen. Dobson unit of 305 means light waves will be having a hard time going through the ozone layer.

Analysis We will now analyze all the different countries, and we can then find out what they have in common and investigate on what affects the solar constant and how truly the solar constant is only. Therefore, we can find a correlation between ozone and solar constant. Country

Ozone Layer/ Dobson unit Qatar 238 England 255

Solar Constant/ W m−2 1.740212 x 10-5 1.601132 x 10-5

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Australia 258

1.701452 x 10-5

Nepal 263 US 305

1.554961 x 10-5 1.546412 x 10-5

Solar Constant/ W m−2/ x 10-5

Ozone Level/ Dobson Units

The graph and the table show a clear correlation between ozone level and Solar Constant. For e.g., a Dobson unit of 238 had a solar constant of 1.740212 x 10-5 W m−2. While the highest ozone level which had a Dobson unit of 305 had a solar constant of 1.546412 x 10-5 W m−2. The only valuable explanation for this is the thicker the ozone layer the harder the sun’s rays have in reaching the surface of the earth. Although there is an anomaly here being Australia. Australia with a Dobson unit of 258 is the only anomaly which hinders the bar graph gives us a negative gradient bar graph. Another area which might also have influenced the solar constant is the land elevation. For this google earths built in land elevation meter will be used. Land elevation can also affect solar constant. Nepal is the highest elevated site out of all the other sites. This is due to the site being in a mountain range in the Himalayas. My hypothesis is that as land elevation increases solar constant is going to increase. Theoretically this should be true as the solar radiation has to travel less to reach the surface of earth thus losing less of its intensity. Therefore, we can plot another graph to find the relationship between solar constant and land elevation. Country

Land Elevation/ m

Solar Constant/ W m−2

England US Qatar Australia Nepal

10 12 52 400 6000

1.601132 x 10-5 1.546412 x 10-5 1.740212 x 10-5 1.701452 x 10-5 1.554961 x 10-5

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Solar Consdtant/ W m-2/10-5

Relationship between Land Elevation and Solar Constant 1.8 1.75 1.7 1.65 1.6 1.55 1.5 1.45 1.4

10

12

52

400

6000

Land Elevation/ Meter

This proves that there is no correlation between land elevation and solar constant. The biggest factor for this is the country USA and Nepal. USA having a lower elevation still has a lower constant than Nepal. This concludes that solar constant and land elevation have no relationship with each other. Albedo is another factor which we can analyses. We can identify the albedo of a certain locations land surface as this is the place where most of the reflection happens. Clouds could be taken as a factor although getting weather data for the all the places at the exact same time can be difficult. Thus, analyzing the albedo of a surface is reliable as the surface is constant all the time. Country Australia England Qatar Nepal US

Albedo/% 17 25 40 53 55

Solar Constant/ W m−2 1.701452 x 10-5 1.601132 x 10-5 1.740212 x 10-5 1.554961 x 10-5 1.546412 x 10-5

Solar Constant/W m-2/ x 10-5

Relationship between Albdeo and Solar Constant 1.80 1.75 1.70 1.65 1.60 1.55 1.50 1.45

17

25

40

Albedo/%

53

55

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Although the bar graph does not’ look very promising, it still can be considered viable. This is because the data for Qatar can be considered an anomaly. This then will be giving us a negative gradient bar graph. Also proving the hypothesis that when albedo increases solar constant will also decrease. This is because as albedo increase the ability of the surface to reflect the sunlight increases. Therefore, the surface does not get as heated as much as the other ones. White can reflect more light than black surfaces because they absorb all visible wavelength since

Conclusion In conclusion, two of my hypotheses were correct which were “As the ozone layer thickness increases the solar constant decreases” and “As albedo decreases solar constant is going to decrease”. While “relation between land elevation and solar constant” was false. Ozone is one of the key factors which can affect solar constant, this is because the ozone acts as a barrier which in turn means that the suns waves will have a harder time penetrating this barrier. This gave us a negative gradient graph proving that as ozone level increases the solar constant decreases the bar graph for this also gave us a negative Albedo is also one of the key factors which can affect solar constant, the causes being that reflection is optimal the whiter the surface is the more it reflects as white light can reflect all the lights from the visible spectrum. To prove this, we got a viable bar graph with one anomaly being the country of Qatar. Otherwise, it ended up giving us a negative gradient bar graph. However, the third hypothesis “As land elevation increases the solar constant increases” resulted being false. The graph for this also gave us a false graph without any meaning or understanding behind it.

Evaluation There were many good aspects in my analysis. I took in account of anomalies resulting in getting a graph with a positive outcome with my two hypotheses. I could have improved it by adding more countries and choosing different countries with a slow and linear increase in land elevation as it would have been a fairer prediction. Also, it would have been better if I had temperature data from 1 or more temperature websites as I would have been able to get an average for it, thus the data being more reliable, and I would also would have been able to get an uncertainty and an average. It would also have been viable if I had done an experiment to find the solar constant of the location I live in, however due to the pandemic this was hard to be done. But most importantly I needed more data generally, so I could have a more variety of graphs, but this was difficult to do as there was limited and unreliable sources online.

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Citations earth :: a global map of wind, weather, and ocean conditions. (n.d.). Null School. Retrieved March 13, 2021, from https://earth.nullschool.net/

Solar constant. (n.d.-b). Encyclopedia Britannica. Retrieved March 13, 2021, from https://www.britannica.com/science/solar-constant

Solar constant. (n.d.). Wikipedia. Retrieved March 13, 2021, from https://en.wikipedia.org/wiki/Solar_constant#:%7E:text=At%20any%20given %20moment%2C%20the,and%20the%20time%20of%20day.

Windy as forecasted. (n.d.). Windy.Com/. Retrieved March 13, 2021, from https://www.windy.com/?25.293,51.532,5

403 Forbidden. (n.d.). OZONE. Retrieved March 13, 2021, from https://ozonewatch.gsfc.nasa.gov/facts/dobson_SH.html#:%7E:text=The%20Dobson %20Unit%20is%20a,of%202%20pennies%20stacked%20together.

Ozone layer. (n.d.). Wikipedia. Retrieved March 13, 2021, from https://en.wikipedia.org/wiki/Ozone_layer

Stefan–Boltzmann law. (n.d.). Wikipedia. Retrieved March 13, 2021, from https://en.wikipedia.org/wiki/Stefan%E2%80%93Boltzmann_law

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albedo | Definition & Examples. (n.d.). Encyclopedia Britannica. Retrieved March 13, 2021, from https://www.britannica.com/science/albedo...