Peter Effertz

My research focuses on two primary subject areas. The first involves analyzing long-term trends and variations in atmospheric ozone, encompassing both tropospheric and stratospheric layers. I serve as the principal technician for the NOAA Global Monitoring Laboratory (GML) Surface Ozone Network, investigating the evolution of global background surface ozone concentrations. Measurement sites are strategically located in remote, pristine regions, minimizing local pollution influences and serving as baseline references for quantifying ozone enhancements observed in urban environments. Additionally, I contribute to the LOTUS (Long-term Ozone Trends and Uncertainties in the Stratosphere) project, with a focus on ozone recovery assessments.

The second area pertains to the development and refinement of ozone retrieval methodologies utilizing the Dobson spectrophotometer. The Dobson instrument has been employed for vertical ozone profile retrieval via the Umkehr technique for approximately nine decades. This technique infers the vertical distribution of atmospheric ozone by analyzing ultraviolet (UV) solar radiation scattered during sunrise and sunset at solar zenith angles between 60° and 90°. My planned work involves updating the retrieval algorithm incorporating contemporary inversion methodologies, such as machine learning algorithms and radiative transfer models. This includes enhancing the understanding of aerosol and cloud impacts on measurements, as well as systematically characterizing and reducing uncertainties associated with the retrieval process.

Surface Ozone:  https://gml.noaa.gov/ozwv/surfoz/

Umkehr: https://gml.noaa.gov/ozwv/umkehr/algorithm.html

LOTUS:  https://lotus.aeronomie.be