We’re hard at work finalizing our lectures, slides, videos, and practice tests for our upcoming course launch at the end of this month.
I made some updates to our curriculum and wanted to share a small section of our lecture on Effects of Weather on Small UAS, which is over 5,000 words and covers topics like:
- Density altitude
- Wind and currents
- Atmospheric stability, pressure, and temperature
- Air masses and fronts
- Thunderstorms and microbursts
- Ceiling and visibility
Below is a text snippet from one of the larger sections in this lecture, titled Wind and Currents. The rest of this section covers sea and land breezes, the effect of obstructions on wind, wind shear, microbursts, and wind and pressure representation on Surface Weather Maps.
Hopefully this gives you an idea of how we teach these concepts.
Wind and Currents
In this section of the lecture, I want to focus on wind and currents.
While wind patterns and the theories of circulation are accurate for large scale atmospheric circulation, they does not take into account changes to the circulation on a local scale. For example, believe it or not, but the friction of the wind blowing along the surface of the earth actually changes its direction from, say 2,000 ft. AGL. Local conditions, buildings and other manmade structures, geological features, and other anomalies can change the wind direction and speed close to the Earth’s surface as well. And that’s where I want to focus.
Different surfaces radiate heat in varying amounts. Plowed ground, rocks, sand, and barren land give off a large amount of heat; water, trees, and other areas of vegetation tend to absorb and retain heat. This uneven heating of the air creates small areas of local circulation called convective currents.
Convective currents cause that bumpy, turbulent air sometimes experienced when flying at lower altitudes during warmer weather. On a low-altitude flight over different types of surfaces, updrafts are likely to occur over areas like pavement or sand, and downdrafts often occur over water or expansive areas of vegetation like a group of trees.