<p>During the night the wind has died and the pollution from agriculture and man made chemicals have settled leaving air quality clear and the sunlight at sunrise is less obstructed and more intense.At sunset all of the above are still lingering in the air making sunlight less intense due to obstruction caused by the pollution.As for the winter being more intense, Precipitation is higher in winter months and the water molecules filter out a large percent of pollution. </p>

CC BY-SA 3.0
2016-01-18T16:10:11.880Z
2016-01-18T16:10:11.880Z
user5434678
<p>I got this image while checking weather data for a city in North India using  Mathematica's Wolfram Alpha query 
<img src="https://i.sstatic.net/jyybk.jpg" alt="WEATHER DATA"></p>

<p>I noticed one feature in the graph which i could not explain .
Why does the encircled part 'A' which denotes  sunrise has slightly higher slope as compared to encircled part 'B' which denotes sunset ! </p>

<p>I also checked the graph for summer month and the pattern was exactly opposite </p>

<p>Summer Month 
<img src="https://i.sstatic.net/jOR7f.jpg" alt="july"></p>

<p>Am i interpreting the data wrong or is it so that sun achieves its highest intensity during the day faster in winter months than in summers ? What could be the reason behind this ? </p>

CC BY-SA 3.0
2014-10-29T16:07:15.100Z
This is unlikely to be the Sun varying in intensity. Much more likely, the instrument is measuring total incident radiation, which includes direct sunlight and also all the reflected light (off clouds, blue sky, etc) that reaches the detector. 

I don't know the local weather patterns, but you COULD get a result like this if mornings were cloudier in one season and evenings cloudier in the other season. Big white fluffy clouds reflect additional sunlight, so you can see how this impacts the rate of change when the sun rises or sets. Can you confirm -- incident radiation or solar radiation?
Tai Viinikka
CC BY-SA 3.0
2014-10-29T16:08:45.950Z
Is this observational data, or a theoretically calculated curve?
Tai Viinikka
CC BY-SA 3.0
2014-10-29T16:33:48.683Z
To my best of knowledge this should NOT be observational data , you can check for yourself at wolframalpha http://www.wolframalpha.com/input/?i=weather+new+york search for "weather history and forecast" then click  "more" then search for "incident sunlight intensity " as all the rest data it shows there is observational there is a good reason to believe this is too but i suspect the intensity of sunlight would follow such a smooth pattern ! So possibly its a theoretically calculated curve ?
Namit Sinha
CC BY-SA 3.0
2014-10-29T19:30:44.253Z
Your hypothesis maybe plausible , yeah i tried searching the web for such(timestamped numerical data) information but failed to find one
Namit Sinha
<earth><weather>
Why does this graph for sunlight intensity on land has a steeper slope during sunrise as compared to sunset?
Namit Sinha
# Why does this graph for sunlight intensity on land has a steeper slope during sunrise as compared to sunset?

(Asked by: username_0 on 2014-10-29)

I got this image while checking weather data for a city in North India using Mathematica's Wolfram Alpha query
![WEATHER DATA](https://i.sstatic.net/jyybk.jpg)

I noticed one feature in the graph which i could not explain .
Why does the encircled part 'A' which denotes sunrise has slightly higher slope as compared to encircled part 'B' which denotes sunset !

I also checked the graph for summer month and the pattern was exactly opposite

Summer Month
![july](https://i.sstatic.net/jOR7f.jpg)

Am i interpreting the data wrong or is it so that sun achieves its highest intensity during the day faster in winter months than in summers ? What could be the reason behind this ?

**Tags:** earth, weather

> **Comments:**
> **username_1**: This is unlikely to be the Sun varying in intensity. Much more likely, the instrument is measuring total incident radiation, which includes direct sunlight and also all the reflected light (off clouds, blue sky, etc) that reaches the detector.   I don't know the local weather patterns, but you COULD get a result like this if mornings were cloudier in one season and evenings cloudier in the other season. Big white fluffy clouds reflect additional sunlight, so you can see how this impacts the rate of change when the sun rises or sets. Can you confirm -- incident radiation or solar radiation?  
> **username_1**: Is this observational data, or a theoretically calculated curve?  
> **username_0**: To my best of knowledge this should NOT be observational data , you can check for yourself at wolframalpha http://www.wolframalpha.com/input/?i=weather+new+york search for "weather history and forecast" then click  "more" then search for "incident sunlight intensity " as all the rest data it shows there is observational there is a good reason to believe this is too but i suspect the intensity of sunlight would follow such a smooth pattern ! So possibly its a theoretically calculated curve ?  
> **username_0**: Your hypothesis maybe plausible , yeah i tried searching the web for such(timestamped numerical data) information but failed to find one  

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## 1 answers

### Answer by username_2 on 2016-01-18. Score: 0

During the night the wind has died and the pollution from agriculture and man made chemicals have settled leaving air quality clear and the sunlight at sunrise is less obstructed and more intense.At sunset all of the above are still lingering in the air making sunlight less intense due to obstruction caused by the pollution.As for the winter being more intense, Precipitation is higher in winter months and the water molecules filter out a large percent of pollution.


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