Image courtesy of Pixabay
By Helen Gloege ’23
Staff Writer
Human activity has a significant impact on the Earth’s atmosphere. The disastrous consequences of changes to the atmosphere have been widely researched regarding carbon emissions, but changing cloud formation and holes in the ozone layer play significant roles as well. Clouds are responsible for simultaneously reflecting the sun’s heat and trapping it in the atmosphere. The ozone serves as a protective layer in absorbing ultraviolet radiation from the sun. It is predicted that as climate change progresses, clouds will diminish in frequency, allowing more solar energy to reach the Earth.
NASA’s ACTIVATE program has planned six flights for researchers to study cloud formations to advance climate models’ accuracy. The third of these flights began on Feb. 3. The campaigns began in 2020 and will end in 2022 with two campaigns each year. From the campaigns, scientists are hoping to understand how variations in particles from human and natural sources affect clouds over the ocean, as well as how clouds may be affecting the removal of particles from the atmosphere. Currently, climate models lack valuable information on cloud feedback, absorption and reflection of solar energy. They hope these campaigns will provide key data.
The study picked the western North Atlantic Ocean, as it provides a wide range of weather conditions and contains a variety of aerosol types. 2020 flights revealed that there is a broad range of cloud droplet concentrations in this area of the Atlantic. These cloud droplets can form on aerosols. The flights also indicated that North American pollution is a major source of aerosols activating into droplets, and there is a trend toward lower particle and drop concentrations at distances further from shore. The study will take samples in cold air outbreak conditions, as dry air will create aerosols near the ocean’s surface to change shape, which alters light that is reflected.
ACTIVATE employs two coordinated aircrafts. One aircraft is an HU-25 Falcon that flies through clouds and takes measurements from the nearby atmosphere. The other aircraft is a King Air that flies at a higher altitude and is responsible for collecting remote sensing measurements and launching dropsondes for weather data. A dropsonde is a weather reconnaissance device that, when dropped from an aircraft, measures storm conditions as it falls to the surface. The current flight campaign will go through March, and the second flight campaign this year is set for May and June. This is part of a larger data collection of five U.S.-based expeditions that focus on air, land and sea.
Human activity’s impact on the ozone layer is another detriment to the Earth’s atmosphere. The ozone layer is considered our protective shield that limits the amount of ultraviolet radiation from reaching the Earth’s surface. These ultraviolet rays are responsible for increasing incidents of skin cancers, eye cataracts, compromised immune systems, damaged DNA and sunburn, along with harm to agricultural lands and forests.
As of April 2020, a larger hole in the ozone that formed over the Arctic was fully healed. Ozone holes have formed yearly over the past 35 years due to human-made chemicals in the stratosphere. To restore the ozone layer, the Montreal Protocol was developed to phase out 99 percent of ozone-depleting chemicals found in air-conditioners, refrigerators and other products. Since 2000, parts of the ozone layer have recovered 1-3 percent every 10 years. This regeneration has helped to curb the effects of climate change. In 2018, it looked like the ozone layer wasn’t healing as quickly as planned. Illegal chlorofluorocarbons production was occurring in eastern China. Specifically, CFC-11 was responsible. CFC-11 is most commonly used in refrigerators and insulators, and when it is released into the atmosphere, it can reach the stratosphere and release chlorine that breaks down the ozone layer. Now, CFC-11 production has declined dramatically, leading to significant ozone recovery.
The atmosphere plays an important role in climate change and climate research. There has been an increase in research done around the atmosphere that will give us a clear idea of the climate’s state and what needs to be done.