Wind Chill: Why the weather feels colder than it actually is?
We've all seen at some point in our lives that there is a "Wind Chill" entry at many weather forecasts. And it is lower than the actual temperature. What is that, and what is it caused by?
It is a fact that at some point we perceive the weather different than it actually is. Yes, it happens for various reasons: it could be our mood, our physiology and it can even be affected by how much we've eaten.
There are various parameters we can take into consideration for calculating the Wind Chill, as there is currently no official formula for calculating it. The most common ones, used by Canada, US the UK are wind speed, humidity and the actual temperature of the forecast. [0]
Let's start from the basics...
The human body is almost constantly working around 37oC by generating heat from our metabolic process (the calories we get from food). When we are outdoors and the wind hits anything not covered by our clothes, we lose heat by conduction. Our skin is getting cooler by the wind (almost as cold as the wind's temperature). If we don't have sufficient clothing, our body temperature will get very low over time. Give it time and hypothermia (our body loses heat faster than it can generate) kicks in below 35oC and if we do nothing it can lead to death. [1][2][3]
Our body is also dissipating heat by moisture evaporation (sweating, breathing, getting wet etc), conduction (transfering heat to our environment), radiation and within our body via our circulatory system.
And how is it calculated?
The wind chill, as I previously stated, is not an exact science. However a standard formula has been established for human use:
Twc is the wind chill temperature (or officially, wind chill index) in the Celsius scale, Ta is the forecast's temperature, and v is the wind speed at 10m height [4]
Why do we feel this?
As we know, the human body is constantly generating heat. Some of this air is dissipated by conduction to the environment. When there is no wind, the heat conduction generates something like a warm air cloak around our body that is somewhat insulating us from the cold weather. However, when the wind starts blowing, this cloak is blown away. For short term exposure there's nothing that can go wrong. We just feel cold. However, our body is trying to compensate for this heat loss by dissipating more heat, and at some point we end up dissipating more heat than we can generate (hypothermia).
Should I take Wind Chill into account?
Yes. You should. And what you can do about it? Wear something extra to protect you from the wind.
Can we feel something like Wind Chill in the summer and feel the temperature higher than it actually is?
Well, you can. It's called Heat Index though! Wind chill though can be felt in summer too, if the conditions are right.
This was my first try to write something educational. It's a short one, and I need you to let me know in your comments if you liked it.
Sources and further reading:
[0] What is wind chill factor? - The Sun
[1] How much heat per hour do humans dissipate? - Physlink
[2] Hypothermia - Wikipedia
[3] BODY (HUMAN) HEAT TRANSFER - Thermopedia
[4] https://en.wikipedia.org/wiki/Wind_chill
Image sources, although both are CC0, they deserve the mention:
First image
Second image
I like the article, and the subject was interesting and easy to understand!
what a simple way of explaining hypothermia :)
Perhaps adding subtitles and a conclusion could be useful for giving more structure to the article? What do you think mate?
Thank you for reading the article and for commenting! I'll keep your suggestions for the next one :)
Good luck with your new attempt!
You can always join the steemstem discord server: https://discord.gg/bEcuhk
and meet lots of other writers that post under the #steemstem tag. Our mentors are also there, ready to help any "newcomer" and offer guidance and valuable advice :)
Thank you very much! New start in my life, new start on steemit as well! xD