Eng Lesson 5 - Eclipse Ballooning Project | Eclipse Ballooning Project

Overview of the content

This lesson offers an introduction to Earth’s atmosphere and meteorology including weather forecasting for balloon flights. You will also learn aboutbasic gravity waves and the process used by the engineering teams to detect them.

Learning objectives

After completing this lesson, students will be able to:

Understand the concept of the atmospheric boundary layer.
Be aware of the surface energy balance and how it influences the boundary layer behavior
Explain the general trends in winds at each layer of the lower atmosphere.
Understand the possible impacts of the solar eclipse and how these impacts could change depending on different circumstances
Identify multiple sources of weather information that is appropriate for balloon flight planning.
Identify weather that can negatively impact ballooning.
Be able to describe the basic concept of gravity waves

Earth's atmosphere: the atmospheric boundary layer

Screen shot from PPT

Introduction to the Atmospheric Boundary Layer -- by Dr. Sean Bailey, University of Kentucky [YouTube video, 33 min, Closed Captioned] Learn about the daily cycle of the boundary layer and the possible effects of an eclipse.

Access / download the slide deck for Introduction to the Atmospheric Boundary Layer

Weather Forecasting

It is essential to check the weather forecast and the trajectory predictions while planning a balloon launch

Launching in high winds can be very difficult and hazardous
Rain can damage payloads, short out electrical systems, and will add a considerable amount of weight to balloon
Fog and low overcast will obstruct visibility

Reviewing trajectory predictions will provide the information needed to

Pick a good launch site
Avoid restricted airspace
Predict an approximate landing zone

(You will learn more about how to predict trajectories in Lesson 9)

Weather models

For weather predictions, use windy.com which shows weather characteristics from different weather models over the next few days for a range of altitudes
Best models to use are the ECMWF and GFS for long range predictions, and then NAM for near term predictions (just a couple days out)
By entering a specific location you can view the steady winds, wind gusts, and precipitation at that location based on each model
When the models agree and when the predictions stay steady for a few days, you can generally have more confidence in their accuracy
Before a front moves through, it’s very hard to predict what will happen afterwards

European Centre for Medium-Range Weather Forecasts (ECMWF)

also known as the Euro model
updates every 12 hours and predicts 10 days out
this model is generally considered the most accurate

Global Forecast System (GFS) Model

also known as the American model
updates every 6 hours and predicts 10 days out
generally considered slightly less accurate

North American Mesoscale (NAM) Forecast System

detailed model specifically for North America
updates twice a day and predicts only 2.5 days out
considered very accurate for near-term US predictions
same as above

The combination of these 3 models generally gives a very good picture of the upcoming weather, and this picture gets more and more accurate as launch day approaches

Gravity waves

Video and slide deck

Gravity Waves -- Video by Mary Catlett, Sarah Gordon, Nick Stegmeier, Mystique Fox - Wyoming Space Grant Consortium and South Dakota Space Grant Consortium [YouTube video, 35:10. Closed captioned, transcript available.]