Background: Plants are essential for thriving in rural areas, especially for agricultural purposes. Carbon dioxide is a greenhouse gas that warms the planet through its ability to hold onto radiation in the atmosphere, which can remain in the atmosphere for centuries.

Plants use carbon dioxide as a way of survival as it pulls down carbon dioxide from the atmosphere to support their growth, as it is used to create their sugar.

New technology called “Direct air capture” allows for carbon dioxide removal from the atmosphere by bringing in carbon dioxide air, capturing it, and sending it below ground for storage, instead of fully relying on plants to remove carbon dioxide from the atmosphere. As a result, the air is released from the direct air capture system. Concerns from the public arise for farmers as the implementation of this technology might cause a lack of plant growth since carbon dioxide is needed for plant growth and energy.

Trends of CO₂: According to the National Ocean and Atmospheric Administration (NOAA), a study was conducted in Mauna Loa to construct Atmospheric CO₂ throughout the years. The graph from these studies shows the increase in atmospheric CO₂ closer to the present year. While there are seasonal fluctuations with Atmospheric CO₂ levels due to farming and other activities, the trend of CO₂ increasing yearly. After 2020, Atmospheric CO₂ rises over 420 ppm (parts per million). This is important as CO₂ can continue to warm our planet.

SGP 30: CO₂: Measures total volatile organic compounds (TVOC) and equivalent CO₂

How does it work? 1) Uses metal-oxide technology to detect gases like ethanol, hydrogen, and other volatile organic compounds (VOCs) 2) Sensor uses these readings to estimate what the CO₂ level might be if humans were the only source of VOCs in the room.

Limitations: The SGP 30: CO₂ Sensor is an indirect measurement of CO₂. This results in a “ball park” guess, which is not an exact measurement. Moreover, this is a consideration of whether humans were the only source of VOCs which different other sources can also emit VOCs.

NDIR CO₂ Sensor: Sensor consisted of several components to take CO₂ measurements. They use an infrared (IR) lamp to direct waves of light through a tube filled with the sample air. The air then moves towards the optical filter in front of an IR light detector. The IR light detector measures the amount of IR light that passes through the optical filter.

Sensors to consider for use: 1) Adafruit MCP9808 QT: Temperature sensor. This sensor gives a high accurate temperature readings as stated on adafruit website the typical accuracy is +/-0.25 Celsius. This to addition to a carbon dioxide sensor could help develop the question and possible answers to how the concentration of carbon dioxide might affect temperature change at different levels of the lower atmosphere. 2) HTU21DF: Humidity & Temperature sensor. This sensor takes measurements of humidity and temperature 3) SHT31: Temperature & Humidity sensor. According to adafruit website, this sensor is more accurate with measurements with an accuracy range of +/-0.25 Celsius. 4) SGP30: MOX Gas Sensor. This sensor would take measurements of eCO₂, which is an indirect measurement of carbon dioxide, as it is an estimated guess of carbon dioxide.

Ballon considerations: Changes in temperature in the higher levels of the atmosphere (Radiative cooling), landing (parachute), weight limits (6-12 pounds), wind movement, battery (if it can run as long as needed), method of data trasnmitting (how will we recieve the data), and radiation (could cause overheating).

Intro & Background Presentation (June 10th, 2025): Michael's Presentation IREC REU 2025: http://www.openscienceassociates.com/delene/REU2025_OverviewPresentation.pdf

Troubleshoot ADPAA:

1. Install ADPAA from the wiki page https://aerosol.atmos.und.edu/ADPAA/index.html
2. Be sure everything is up to date (In terminal: sudo apt update), if not, then upgrade needed software(IN terminal: sudo apt upgrade)
3. Ensure you have a Python environment and other needed tools installed in the terminal: sudo apt install python3 python3-pip csh tcsh gfortran git
4. Encountered the problem of trying to find ADPAA (It was in downloads: cd ~/Downloads), CoPAS
5. In terminal: ls *.tar.gz (To find the download of ADPAA since it will be an .tar.gz file
6. When trying to install and open wget was not installed, if it is not in terminal: pip3 install wget
7. Install ADPAA in terminal: ./CoPAS.py ADPAA
8. If you encounter “git” not defined error download the package in terminal: pip3 install gitpython
9. Follow the other steps of https://aerosol.atmos.und.edu/DataProcessingGuide.pdf
10. To test type aplot in terminal (Aplot is an open source software for processing and analyzing raw data.
11. For ADPAA, you have to manually install it on Raspberry Pi through the terminal and edit the source code for your login

Guideline to wiring for 3D-PAWS:

• Color does not matter but once you assign each wire, they matter
• The most important pins: Power (typically 3.3V), Ground (GND), Clock (GP103: SCL1), and Data (GP102: SDA 1)
• About the Raspberry Pi USBs being on the left side, the pins start in a number order, left being the first: Power 3.3V (1st pin), if 5V power (2nd pin), Ground (6th pin), Clock (5th pin), and Data (3rd pin)
• Each sensor will have the code name above to see which wire plugs in where on the sensor
• For the BMP280: SCK is the Clock pin, SDI is the Data pin
• To test if the Raspberry Pi is detecting any sensors in terminal: sudo i2cdetect -y 1 (It will be a diagram with dashes and numbers should show for each sensor: if you have 3 sensors, three different values should be present)

How to wire:

1. Assign any color of wire a specific use: Ground (GND), Power (usually 3.3V, if not 5V), Clock (GP103: SCL1), and Data (DP102:SDA 1)
2. If you are daisychainning them together, cut the end you do not need and stripe it to expose wiring
3. Twist the wires you want together with the same color/purpose (example: 3 power wires, yellow in this example, for 3 different sensors, you would twist them together and solder them together
4. Solder is in the main lab (pen and metal coil with it)
5. Cover the solder part with a small tube and hot glue to seal it (in the 3D paws bin)
6. Connect the female connectors to GPIO pins on the board of the Pi and sensor pins (coordinate which pins are the correct wiring purpose: Ground, Clock, Data, and Power.

Presentation (July 15th, 2025)

Summer 2025 Abstract: Weather balloons are used by scientists and researchers to collect measurements of the atmosphere, and vertical profiling helps create an account of how scientific measurements differ at each altitude. Current research includes developing vertical profiling of carbon dioxide concentrations using aircraft and satellite technology. This type of research faces challenges through temperature profiling error, lack of ground data in certain regions, and instrument biases. In this research project, we aim to develop a vertical profile of carbon dioxide by using two different carbon dioxide sensors during a weather balloon flight. A Raspberry Pi 3B model was used in this project, and code for each sensor was programmed to start automatically on the Raspberry Pi when the Raspberry Pi is powered on. Wiring was created to attach the Raspberry Pi GPIO pins to the SGP30, BMP280, and HTU21D-F sensors to collect data. The scripts and sensors were tested using ground samples. Lastly, the weather balloon was launched to collect and analyze the atmospheric data. Unfortunately, data retrieval was not successful due to the memory card on the Raspberry Pi becoming physically damaged on landing. However, ground testing revealed that both the SGP30 and COZIR carbon dioxide sensors disagree on average by 26 ppb. This project will help future development of weather balloon projects through systems failure analysis. Furthermore, the carbon dioxide sensor data analysis will help in understanding the validity of sensor measurements for constructing future vertical profiles.

Used in the package for 2025:

1. COZIR: CO2 sensor
2. SGP30: CO2 sensor & TVOC
3. HTU21D-F: Humidity sensor
4. BMP280: Pressure & Temperature
5. iMet XQ2: Radiosonde that measures pressure, temperature, altitude, and humidity
6. Apple Airtage
7. Spot Tracker
8. 10,000 mAH Anker battery pack (Power Raspberry Pi)

Code for sensors (Summer 2025):

1. bmp280_logger.py: Logs data from the pressure and temperature from the BMP280 sensor and stores it in a CSV file to log the data (5-second collection interval)
2. htu21d_logger.py: Logs data from the htu21d sensor and collects temperature and humidity. It stores the measurements and logs them automatically in a CSV file. (5-second collection interval)
3. sgp30_logger.py: Logs carbon dioxide (eCO2) and Total Volatile Organic Compound (TVOC) from the SGP30 sensor into a CSV file automatically. (5-second collection interval)
4. IMetXQ2_tri.py: Logs data from IMetXQ2 and measures pressure, altitude, humidity, and temperature, and logs the measurements into a CSV file. For this code, you need to go in and change the USB_port to the correct port. (cd /dev and ls: plug and unplug, and you will see the name that changes. Run the script after cd /dev: ls and plug, then unplug and see which one was removed).
5. Each sensor has a comment code to add a time stop feature, so the code will automatically stop at a certain hour it reaches. To add it: remove # from the line of code and change “from datetime import datetime” to “import datetime”. Remove the lines that have datetime.datetime(etc….) to a single datetime.(etc…).
6. Where it has (hours= #). Change the numerical number to the value of how long in hours you want the code to run and stop. For example, (hours=1) the code will run for an hour and stop itself automatically
7. When troubleshooting the code, there were some indent errors, so ensure each indent is correct

Analysis for future projects:

1. Larger Parachute: The parachute in the garage is not big enough for a 10 ft height, 12.5 ft length, and 9ft width. The parachute did not deploy correctly on the Summer 2025 balloon launch. When we retrieved the balloon, the string broke off, and the bottom of the knot at the bottom of the package was intact, but the string going through the package looked as if it had been snapped.

• Liz Cardoza worked on project during 2024 Summer REU, see REU Poster
• Michael Witherspoon 2025 Summer REU