Narragansett Ozonesonde Campaign
Ozone is a minor but important constituent of the natural atmosphere, and also a very important secondary pollutant, a substance whose mixing ratio is notably variable in both space and time. Thus observation and analysis of the distribution of ozone and its variability are essential, fundamental requirements.
A campaign of weekly sonde ascents to measure the vertical profile of ozone has been underway at the Narragansett Bay Campus since the spring of 2004. Using supplies and ground equipment provided by the NOAA ESRL Ozone and Water Vapor group, we prepare, release and receive data from balloon-borne Electrochemical Cell Ozonesondes. When additional funding is available, we participate in intensive observation exercises, often releasing sondes daily. Here we summarize the observational effort and highlight some interesting results and curious occurrences.
| Table of Observations | Summary Plots | Table of Observations | Summary Plots |
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including INTEXNA intensive |
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including INTEXB intensive |
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including ARCIONS intensive |
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The Table of Observations list the profiles observed in each year, and link to a plot of the data from each sonde. The Summary Plots linked in the table above give an overview of the ozone distribution and its variability for each year.
This analysis was carried out primarily by Kaitlin Walsh, now a graduate student at the School of Earth Sciences, Byrd Polar Research Center, The Ohio State University. Kaitlin was an intern in our group in the summer of 2009, supported in part by the Rhode Island State Internship program. Kaitlin graduated from Pennsylvania State University in 2009.
Site and Equipment Gallery
The laboratory setup used to prepare ozonesondes is shown here. The sonde instrument sits in front of the KTU 100 unit in the left half of the picture. A pressure gauge, ozone removing filter, stopwatch, bubble flow meter and other tools are also shown.
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Close-up picture of an ozonesonde being readied for use. Here ozone-rich air generated within the KTU-100 is pumped into the sonde cathode cell. The cell leads are connected to the KTU-100 (white and blue wires), and the sonde air pump is powered by the KTU-100 (twisted red and black wires). This setup is used to measure the response time of the sonde cell, a characteristic that varies from one cell to another.
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When a sonde is ready for use it is packed in an insulating box, and a radiossonde (Vaisala, Inc.) is attached and taped to the outside of the box. The leads visible on the left side of the box allow the battery for the sonde to be connected after the box has been closed for flight. The radiosonde has a battery of its own, and the connector for this is visible at the lower right. This setup allows testing of the complete system using laboratory power sources, and the batteries are connected immediately before the flight. |
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This shows the (back side of) the radio receiver used to capture the profile data. The coaxial cable connects the antenna to the receiver. The signal is fed to a low-bandwith modem, which is on top of the receiver. This converts the warbling signal to a string of characters, which are picked up and saved by the computer program strato. |
This shows the inflation of a balloon, in preparation for a profile. The latex balloon, at 1.2 kg, is the heaviest part of the flight package. About 3000 liters of compressed He gas are used for each flight. There is a ballast element that's used to determine how much gas is used to fill the balloon. Also shown here is the simple parachute that's included in the balloon train, to slow the package in descent (after the balloon has burst). |
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This shows the balloon/sonde package during ascent. Just below the parachute is a reel of string with a ratchet and pawl setup which pays out lightweight string, to separate the sonde package from the balloon. This slows the pendulum-like oscillations of the sonde as the balloon ascends, and minimizes heating by sunlight reflected from the balloon. The balloon increases substantially in size during ascent, reaching a diameter of almost 30 feet when it bursts. |
