Related Experiment Video
Updated: Jul 12, 2026
06:27
Measurement of Aerosols Optical Thickness of the Atmosphere using the GLOBE Handheld Sun Photometer
Published on: May 29, 2019
Summary
Global total ozone levels showed a significant upward trend between 1957 and 1970. The Northern Hemisphere experienced a 7.5% per decade increase, while the Southern Hemisphere saw a 2.5% per decade rise.
Area of Science:
- Atmospheric science
- Ozone layer research
- Climatology
Background:
- The Earth's ozone layer is crucial for absorbing harmful ultraviolet radiation.
- Understanding long-term ozone distribution trends is vital for climate modeling and environmental protection.
Purpose of the Study:
- To analyze global total ozone distributions over a 13-year period.
- To identify and quantify any significant trends in ozone levels across hemispheres.
Main Methods:
- Analysis of mean monthly global total ozone data.
- Statistical examination of ozone distribution patterns from 1957 to 1970.
Main Results:
- An upward trend of approximately 7.5% per decade was observed in the Northern Hemisphere.
- A slower upward trend of about 2.5% per decade was detected in the Southern Hemisphere.
- Ozone increases appear to have commenced around March 1961 (Northern Hemisphere) and September 1961 (Southern Hemisphere).
Conclusions:
- Significant hemispheric differences in total ozone trends were identified during the study period.
- The underlying causes for these observed ozone trends remain undetermined.
- Further research is needed to investigate the drivers behind the global ozone increases.
Related Concept Videos
01:50Global Climate Change
Throughout its ~4.5 billion year history, the Earth has experienced periods of warming and cooling. However, the current drastic increase in global temperatures is well outside of the Earth’s cyclic norms, and evidence for human-caused global climate change is compelling. Paleoclimatology, the study of ancient climate conditions, provides ample evidence for human-caused global climate change by comparing recent conditions with those in the past.
01:50Threats to Biodiversity
There have been five major extinction events throughout geological history, resulting in the elimination of biodiversity, followed by a rebound of species that adapted to the new conditions. In the current geological epoch, the Holocene, there is a sixth extinction event in progress. This mass extinction has been attributed to human activities and is thus provisionally called the Anthropocene. In 2019 the human population reached 7.7 billion people and is projected to comprise 10 billion by...
01:27Microbes and Climate Change
Microorganisms are pivotal agents in Earth's biogeochemical cycles, significantly influencing climate dynamics through their metabolic activities. These microbes modulate the levels of key greenhouse gases by both contributing to and helping mitigate climate change.Microbial Contributions to Greenhouse Gas EmissionsRising global temperatures accelerate microbial metabolism, which, in turn, speeds up the decomposition of organic matter. This process releases carbon dioxide (CO₂) through...
01:29Oxygen Requirements and Growth Patterns
Microorganisms exhibit diverse oxygen requirements and growth patterns driven by their metabolic strategies and environmental adaptations. Oxygen, while essential for many organisms, can also be toxic under certain conditions, shaping how microorganisms grow and survive.Oxygen Requirements of MicroorganismsMicroorganisms are classified based on their ability to use or tolerate oxygen:● Obligate aerobes like Mycobacterium tuberculosis need oxygen for energy production, as it serves as the...
01:14The Carbon Cycle
Carbon is the basis of all organic matter on Earth, and is recycled through the ecosystem in two primary processes: one in which carbon is exchanged among living organisms, and one in which carbon is cycled over long periods of time through fossilized organic remains, weathering of rocks, and volcanic activity. Human activities, including increased agricultural practices and the burning of fossil fuels, has greatly affected the balance of the natural carbon cycle.
03:40Hess's Law
There are two ways to determine the amount of heat involved in a chemical change: measure it experimentally, or calculate it from other experimentally determined enthalpy changes. Some reactions are difficult, if not impossible, to investigate and make accurate measurements for experimentally. And even when a reaction is not hard to perform or measure, it is convenient to be able to determine the heat involved in a reaction without having to perform an experiment.