This interview has been edited for brevity and clarity.
Bill Burton: It's time for us to take a look at the Science Behind the Forecast as I am joined by WAVE 3 meteorologist Tawana Andrew. Good morning, Tawana.
Tawana Andrew: Good morning. Today's topic is a bit hair raising.
BB: Oh, I see what you did there. That's very good. We are talking about hair even though it is Science Behind the Forecast, because hair can be affected by the weather that we're experiencing, specifically humidity.
What do we need to know about humidity and hair?
TA: So first we need to break down how our hair is comprised.
Human hair consists of three separate layers, the medulla, which is the innermost layer of your hair, the hair strand. The cortex, which is the middle and then the cuticle, which is the outermost layer.
The medulla is what retains a lot of moisture, and it's predominantly found in thicker or more coarse hair. For the cortex that comprises the majority of the hair strand, this is where you have the keratin protein molecules that define your hair shape, thickness. This is where genetics and the hair follicle also comes into play with those shapes and thicknesses.
And then the cuticle serves as protection for the cortex, but that's a little bit finicky. That could be easily damaged, and once the cuticle is compromised, that is when you end up with moisture loss or gain in the cortex, which can lead to split ends, breakage or even frizz.
So those long protein molecules basically contain positive and negative charges. So that leads to the entire rows of proteins to kind of line up and act as weak magnets. Hydrogen bonding in the cortex keeps our keratin protein molecules aligned. But then you start to add in moisture that can disrupt the bonds of these protein molecules, because water can form hydrogen bonds in between the hair proteins, and that is how you end up with frizz.
Fun fact, I did not know this before I was doing the research for this, but a lot of people blame added humidity for frizz. But if you style your hair in high humidity, and then you go into drier air and less humid air, that can also cause frizz.
BB: Wow. The more you know.
TA: So it works both ways, and humidity plays, of course, a significant role in our hair texture. With high humidity, that kind of helps to open up some of the cuticles, allowing that extra moisture in and it's important to know, as you know how much moisture is in the air.
So we either use dew point or relative humidity to help figure out how humid things are as you're heading out and about. So for air moisture levels, keep in mind that if the dew point is above 60 degrees, that usually means that we're dealing with a lot of humidity, and in the summertime, we're basically always dealing with a dew point above 60 degrees. There's always going to be moisture in the air. And if the relative humidity is above 50% that also suggests that humid conditions are present.
And interestingly enough, scientists, meteorologists, do use hair in what's called a hygrometer. And we use hygrometers to measure humidity, so you are literally measuring the humidity with your hair as you're heading out.
BB: Fascinating. Should it be called a hairgrometer then?
TA: I prefer that. I think that's what we should have rolled with first.
