Case Study – Post 16 – INS Guindabols

Case Study – Post 16 – INS Guindabols – Lleida, Spain

Study of the Atmosphere by using the Data collected by a Weather Balloon

The students of Baccalaureate attended the launching to the stratosphere of a weather balloon on the 19th April 2018. The balloon was equipped with different kinds of sensors and electronic devices, such as a GPS, a radio set, and a webcam.

By using this balloon, students undertook their research related to the atmosphere data which had been collected by the sensors.

Define the problem

The students worked in groups of 4-5, and with the teachers’ help, they first explored the following questions:

How will some physical magnitudes change with height?
How will radioactivity change with height? Why? How will the movement of the balloon be when it rises? And when will it go down?
Can the wind speed be measured?
How can be the Earth’s Albedo determined?
They also investigated the following questions using images taken from the equipped camera.
Can the most characteristic geographic peaks in the Pyrenees be recognised?
Why is the sky black?

This photo shows the curvature of the Earth.

Can you think of any experiment to prove that the earth is spherical?
How would you make an estimate length of the radius of the Earth from the image?
Which day and where could the weather balloon be launched?
How can the route be predicted? Where will the balloon fall?

After the brainstorming of the problems, the students decided to explore:

Explore the problem

They then started investigating these problems:

Which data are needed in order to solve the research question?
Which graphic representation is more appropriate?
Which statistical treatment is most suitable?

Click to enlarge

Click to enlarge

The table shows the data obtained by the different sensors:

TIME (min)	HEIGHT (m)	INTERN TEMP.(Cº)	EXTERN TEMP. (Cº)	DIRECTION (º)	SPEED (km/h)
0	13141	9	11	247	26
1	13504	8	-32	302	37
2	13911	8	-32	277	37
3	14294	7	-32	286	43
4	14693	7	-32	288	15
5	15075	7	-31	54	15
6	15480	6	-31	314	9
7	15834	6	-30	279	20
8	16221	5	-30	35	24
9	16573	5	-29	138	19
10	16937	5	-28	267	24
11	17304	4	-28	3	22
12	17656	4	-28	342	24
13	18023	4	-28	31	20
14	18393	4	-27	38	19
15	18768	4	-26	40	20
16	19153	3	-26	280	2
17	19534	3	-25	131	15
18	19913	3	-25	235	33
19	20297	3	-24	310	7
20	20693	3	-24	173	35
21	21099	2	-24	315	7
22	21455	2	-25	217	17
23	20313	2	-36	209	24
24	19284	2	-38	279	28
25	17364	2	-44	257	41
26	16495	2	-46	250	30
27	15668	1	-48	273	26
28	14823	1	-48	355	41
29	14013	1	-49	236	30
30	13255	0	-51	224	20
31	12564	0	-51	250	70
32	11906	0	-51	296	115
33	11280	-1	-50	287	137
34	10683	-2	-47	273	128
35	10104	-3	-44	294	119
36	9552	-4	-41	274	52
37	9025	-4	-38	241	31
38	8526	-5	-35	236	48
39	8037	-6	-31	216	33
40	7574	-6	-27	284	33
41	7132	-7	-23	242	52
42	6680	-7	-20	207	37
43	6221	-7	-17	249	52
44	5769	-7	-14	240	48
45	5364	-7	-10	226	50
46	4976	-7	-7	238	50
47	4601	-7	-5	232	37
48	4230	-6	-4	249	41
49	3832	-6	-2	283	54
50	3454	-5	0	304	24
51	3088	-4	1	271	30
52	2754	-4	2	264	37
53	2165	-2	4	318	35
54	1854	-1	6	291	46
55	1553	0	8	298	28
56	1250	0	11	291	30

In order to obtain and determine the graphic and statistic data, the students used tools such as Excel, CurveExpert and CODAP.

Conclusions

The Erath’s albedo in the Eastern geographical area of Spain is 28, although the average is 0.38. This difference between the data is due to the fact that there are many factors that influence this calculation which may change the result, such as the type of surface when the rays of the sun fall upon.
The maximum horizontal wind speed was 137 km/h during the descent at 13.255 m. The minimum speed was 2 km/h during the ascent at 18.768 m. The highest altitude is 455 m. The area where the wind currents most affect the probe is between 13.000 m and 15.000 m. In there ,the weather balloon reaches the maximum horizontal speed during the ascent and the descent
The weather balloon rises up to an altitude of 455 m in a practically constant speed of 5 m/s. However, the speed in the descent is absolutely constant and it is of 7 m/s.
The probe begins to record data at 141 m. The internal temperature is of 9 degrees and descends to 0 degrees when it reaches 11.906 m. The temperature continues to decline below zero to 4.601 meters reaching -7 degrees. From this measure, the temperature rises again to 0 degrees and an altitude of 1.250 m.

At 14.013 m. the minimum external temperature is 49 degrees below zero.

The calculated value of the radius of the Earth is 1.175km .We compared our result with the real radius of the Earth (6371 km), and we noticed that we made a very big mistake. This may be due to the distortion of the image we had and the margin of error in our calculations.

Although the result was not what we expected, it is a very practical activity and gives the balloon probe a new utility.

The main benefits of undertaking such a project- based learning are:

The students worked in groups in an autonomous and efficient way that helped to get group cohesion.
The project allowed us to work with the PBL and STEAM methods.
Students became more enthusiastic when tackling with Science and scientific vocations have been promoted thus.
Coordination between different school departments (Science, Maths, Physics, English ) improved.