Did You Know? Science Facts with Julie
The waning of our snowpack is a common conversation this time of year and made me think that it’d be a good E-News topic. Searching on the web, I came to learn that this process is a lot more complex than one might think. There are many different factors that affect the rate of snowmelt, the most obvious being air temperature and sun exposure. When we think of sun exposure, we think of the sun melting the snow into water. However, some of the effect of solar radiation is actually to turn solid snow into a gaseous phase (water vapor), a process called sublimation.
But there are several other important factors – think about how quickly we lose our snowpack when we have warm Chinook winds. Why? Strong, warm winds cause snow to sublimate by rapidly removing water vapor from the snow surface, allowing drier air to come along and thereby removing more water vapor (i.e., removing the snow).
What about the influence of dark objects and snow melting at a faster rate around dark objects? This is known as the “black body effect” and includes some quite complex physics. I’ll direct you here to learn more about this process.
Rain - the warmth of water (warmer than snow) causes some direct melting of the snow. In addition, rain results in snow melt indirectly through the loss of airspace in the snowpack. Air in the snowpack serves as an insulator and makes the snow less sensitive to melting from warm air temperatures. And then there’s the influence of snowpack density and ground temperature. Ah, so much to ponder. Happy Spring!