Erlangen 2018 – wissenschaftliches Programm

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UP: Fachverband Umweltphysik

UP 7: Atmosphere - lab studies

UP 7.2: Vortrag

Dienstag, 6. März 2018, 18:00–18:15, G 1.011

Precision measurements of the absolute ozone absorption cross section at the 325 nm HeCd laser line - the resolution of a long standing ozone puzzle ? — •Christof Janssen^{1, 2}, Hadj Elandaloussi¹, and Julian Gröbner³ — ¹LERMA-IPSL, Sorbonne Université, UPMC Univ. Paris 06, CNRS, Observatoire de Paris, PSL Research Univ., Paris, France — ²Institut für Umweltphysik, Universität Heidelberg, Heidelberg, Germany — ³Phys. Meteorol. Observatorium Davos, WRC, Davos Dorf, Switzerland

Ozone is a key molecule in the Earth's atmosphere and the study of ozone hole recovery has become a major topic. Recovery rates being slow and depending on many factors, global and long-term observations of high accuracy are required to derive meaningful trends. While diverse observational platforms (from ground, balloons or satellites) provide such measurements, uncertainties and inconsistencies of the spectroscopic database being used for ozone retrieval are of considerable concern for the quantification of concentrations and trends.

In this talk, we will first introduce common measurement methods as well as currently used and recommended reference data in the UV and IR. We will discuss where and to which extent inconsistency problems exist. Then we present new highly accurate measurements of the absolute absorption cross section of ozone at the 325 nm wavelength of the HeCd laser. These measurements, as well as our previous work at 253.65 nm and in the IR shed new light on currently used absorption spectroscopic data used for ozone remote sensing, as they reveal potential biases in the UV and the IR spectral regions.