Historic Mount Washington Summit Visibility Investigation & Analysis

• •  To explore the availability and quality of visibility data on Mount Washington
  •  To conduct an initial analysis to determine what, if any, trends were apparent since 1943
  •  Overall, a general increase in visibility has been reported since continuous visibility records started at MWO
    
    Download Historic Visibility Data Exploration and Analysis report

Mount Washington Observatory meteorologists have observed prevailing surface visibility nearly every hour since 1942 with few gaps. However, these data were largely unavailable to the public, and until recently had not undergone quality control and long-term analyses. Specifically, an analysis of prevailing visibility was of interest in order to determine if any long-term trends or anomalies exist.

Motivation for the investigation was initially born from public inquiry about whether MWO was witnessing a significant difference in reported prevailing visibility with a reduction in air traffic and other industry due to the COVID-19 Pandemic. Often referred to as the “tailpipe of America,” prevailing west to east winds transport aerosols and particulate pollution from the Ohio River Valley and further west to New England causing reduced visibility and air quality. As the highest point in the Northeast with a treeless summit, Mount Washington’s position allows for an unobstructed view in all directions and a maximum clear-sky visibility of 130 miles with peaks as distant as Mount Marcy in New York State visible to the naked eye.

Unpublished analysis of historical visibility data at Blue Hill Observatory indicates a statistically significant increase in 7am daily visibility reports since 1965 (Iacono 2020). With over 70 years of hourly visibility data, a time-series analysis of MWO’s long-term visibility will help researchers understand if regional visibility has changed over time.

An exploration and initial analysis of Mount Washington visibility data will be a crucial first step in making public data that otherwise have largely been unexamined. Director of Science & Education Brian Fitzgerald will serve as project manager and MWO’s point of contact for this investigation. Additionally, MWO’s Science Committee and Committee Chair Dr. Mary Stampone will provide project oversight and guidance to MWO Weather Observers who will conduct the majority of this exploration and analysis.

In addition to being valuable to MWO because of the opportunity to investigate this little-explored data set, this project would provide previously unavailable long-term data at a unique elevation (6,288 feet) in Northern New England. Findings from this project would likely be of value to air quality specialists, meteorologists, the general public and beyond because of impact of air quality on weather, climate and environmental health.

Iacono, M.J. (2020). [Blue Hill Observatory Seasonal Visibility, 1965-2019]. Unpublished raw data.

Brian Fitzgerald, Director of Science & Education

(603) 356-2137 ext. 225

Email (link: mailto: bfitzgerald@mountwashington)