How is the air quality in Yosemite?

The below article talks about air quality in Yosemite, the sources that contribute to these levels, practices that are enforced to address air pollution in the country, along with some frequently asked questions about the same.

How is the air quality in Yosemite?

Yosemite, on average for the most part of the year, experiences average to healthy levels of air quality. The fluctuations seen via poor air quality in the area can be attributed to several geographical patterns, meteorological events, etc. This is not to say that anthropogenic sources have no impact on the air quality in the area, it is that the geographical restrictions in the area could sometimes slow the rates of dispersion of any pollutant, due to which the area may face extended periods of poor air quality. Currently, the area experiences moderate air quality, the dominant pollutant is particulate matter (PM2.5), which is said to be 5.4 times higher than the limits set by WHO (IQAir, 2022 February 18). 

Air Quality in Yosemite 

Source: tomorrow, 2022

The above image is a depiction of the main pollutants in the Yosemite area. As you can see, most pollutants are within the normal ranges. The concentration of particulate matter (PM2.5) is of concern but does not pose much of a threat right now for the larger population in the area. It is however advised that sensitive groups of the population including chronically ill individuals, kids, senior citizens, etc. minimize their exposure to these environments, as it could have a negative impact. 

Understanding why the area experiences poor air quality from time to time is important, especially when it comes to learning what kind of mitigatory frameworks would be employed in the area to address air quality concerns. First and foremost, it is to be observed that the bowl-shaped topography of the Central Valley traps pollution from vehicular sources, factories, industrial activities, private or domestic stakeholders, and power plants in the region. As the pollutants are released, westerly winds blow the pollution, including particulates and nitrogen oxides, into Yosemite, particularly during the summer months. This phenomenon creates a smothering effect through a blanket of pollutants in the area, thus reducing the air quality. These pollutants and geographical conditions combined have been found to cause a smoggy appearance to the area, and have had devastating impacts on citizens including the trigger of illnesses like asthma and chronic obstructive pulmonary disease.

Besides just anthropogenic sources of greenhouse gases and pollutants, another major threat the area faces is pollution from wildfires. In the past year (2021), Yosemite had experienced 72 wildfires, 50 caused by lightning, and the rest were triggered by careless human activities. Several measures have been taken to suppress the fires and to contain them, however, the fact remains that a lot of lands and other natural resources were burnt and it led to a large number of toxic emissions of particulate matter that seemed to smother the city for months on end. As weather conditions keep changing, wildfires would continue to grow in the following years, but it must be noted that poor air quality in the area would continue due to anthropogenic sources regardless of the wildfires, it is that wildfires exacerbate the current air quality patterns in the area. 

Below is an image that shows the transition of air quality levels in the area from February 11, 2022, to February 18, 2022. As seen below, the air quality levels had dropped from healthy levels due to an increase in the concentration of particulate matter (PM2.5). 

Source: NPS, 2022

Source: NPS, 2022

Frequently Asked Questions (FAQs): How is the air quality in Yosemite?

Which cities in the US have the worst air quality?

Source: IQAir, 2022 February 18

#City US AQI
1Ahwahnee, California190
2Happy Camp, California158
3Weed, California147
4Macdoel, California144
5Hoopa, California126
6Westwood, California123
7Kremmling, Colorado121
8Lake City, Colorado119
9Tulare, California119
10Walnut, California116

What are the air quality levels across Yosemite currently?

Source: IQAir, 2022 February 18

#City US AQI
1Ahwahnee Drive82
2Yosemite Village – Visitor Centre63

Which cities in the US have the best air quality?

Source: IQAir, 2022 February 18

#City US AQI
1Athens, Tennessee0
2Battlement Mesa, Colorado0
3Black Forest, Colorado0
4Blaine, Idaho0
5Borrego Springs, California0
6Bristol, Tennessee0
7Bristol, Virginia0
8Caribou, Maine0
9Cathedral City, California0
10Cedar Park, Texas0

Other FAQs about Air quality that you may be interested in.

How is the air quality in the Philippines?

HOW TO IMPROVE BASEMENT AIR QUALITY

Can Air Pollution Make You Sick?

References 

IQAir. (2022, February 18). Air Quality in USA.  Air quality index (AQI) and PM2.5 air pollution in USA. Viewed on 02-18-2022. https://www.iqair.com/in-en/usa  

IQAir. (2022, February 18). Air Quality in Yosemite Valley. Air quality index (AQI) and PM2.5 air pollution in Yosemite Valley. Viewed on 02-18-2022. https://www.iqair.com/in-en/usa/california/yosemite-valley 

IQAir. (2022, February 18). Real-time USA city ranking. Live AQI city ranking. Viewed on 02-18-2022. https://www.iqair.com/in-en/usa/california/yosemite-valley 

IQAir. (2022, February 18). Real-time USA cleanest city ranking. Live AQI city ranking. Viewed on 02-18-2022. https://www.iqair.com/in-en/usa 

IQAir. (2022, February 18). Real-time Yosemite Valley air quality ranking. Live Yosemite Valley AQI Ranking. Viewed on 02-18-2022. https://www.iqair.com/in-en/usa/california/yosemite-valley  

tomorrow. (2022, February 18). Air Quality in Yosemite Valley, California, United States. Viewed on 02-18-2022. https://www.tomorrow.io/weather/US/CA/Yosemite_Valley/129712/health/ 

Rudee A. (2017, September 19). Yosemite’s dirty air secret. National Parks Conservation Association. Viewed on 02-18-2022. https://www.npca.org/articles/1640-yosemite-s-dirty-air-secret 

National Park Services (NPS). (2021). Fire Update, October 2, 2021. Yosemite National Park, California. Viewed on 02-18-2022. https://www.nps.gov/yose/blogs/fire-update-october-2-2021.htm  

National Park Services (NPS). (2022). Air quality and smoke monitoring. Yosemite National Park, California. Viewed on 02-18-2022. https://www.nps.gov/yose/learn/nature/aqmonitoring.htm 

Sierra Sun Times. (2021, August 20). Yosemite National Park Fire Update for Friday, August 20, 2021 – Tiltill Fire at 1,960 acres with 90% containment. Viewed on 02-18-2022. https://goldrushcam.com/sierrasuntimes/index.php/news/local-news/32438-yosemite-national-park-fire-update-for-friday-august-20-2021-tiltill-fire-at-1-960-acres-with-90-containment