UNB Physics Department Seminar-FR

Event date(s): October 16, 2025
Time(s): 01:15 PM - 02:15 PM
Category: Fredericton
Location: Fredericton

UNB Physics Department Seminar

When: Thursday, Oct. 16, from 1:15 - 2:15 p.m.
Location: Carleton Hall room 139

Speaker: Dr. Patrick Sheese of University of Toronto

Title: The Atmospheric Chemistry Experiment: A Funny Thing Happened on the Way to the Fourier Transform Spectrometer

Abstract: In 2013, a decade after the launch of the Atmospheric Chemistry Experiment (ACE), I was hired as the "ACE Validator" and was tasked to produce a set of data quality flags for measurements made by its Fourier Transform Spectrometer (ACE-FTS). As an enthusiastic, yet undeniably dilettantish, vexillophile, creating quality flags seemed like a dream job! It was my job to come up with a singular algorithm that could flag 70+ atmospheric data products (e.g., vertical profiles of ozone, water vapour, temperature, greenhouse gasses, CFCs, HCFCs, HFCs, etc.) for physically unrealistic measurements throughout the upper troposphere to the lower thermosphere. It's now over a decade later, and, with ACE still routinely making solar occultation measurements through the Earth's limb, the flagging algorithm is on it's third version. Each month, a manual check on the flagging routine and its output is performed, and this procedure has led to a number of fascinating discoveries. This talk will be a flags-to-scientific-riches story where I discuss the ACE-FTS instrument, its data flagging procedure, and how that procedure has led to atmospheric discoveries such as atmospheric production of N2O, a sudden global enhancement of stratospheric HCN, and a "stratospheric tsunami" following the eruption of the underwater volcano Hunga-Tonga Hunga-Ha'apai.

Building: Carleton

Room Number: 139