Scientists at Anhui Institute of Optics and Fine Mechanics (AIOFM), Hefei Institutes of Physical Science have made new improvement on Instrumental Line Shape, or ILS treatment for gases retrieval with high resolution solar spectra, cooperating with researchers from University of Bremen, Karlsruhe Institute of Technology and University of Wollongong.

In the process of Network for Detection of Atmospheric Composition Change, or NDACC gases retrieval, the ILS can be assumed as ideal if spectrometer is well aligned. If misalignment exists, dedicated cell measurements or retrieval with the gas profile from an atmospheric spectrum should be operated using a polynomial.

However, characterized by high complexity, diversity, and sensibility, the influence of ILS treatments on the the NDACC gases retrieval remains unknown and how much ILS deviation from unity is acceptable for each NDACC gas is still not fully quantified.

The Sino-German joint team, for the first time investigated the influence of ILS degradation on total column and profile retrievals based on the current standard NDACC gas measurements.

Scientists also deduced the maximum ILS deviations allowable for suppressing the influence within a specified acceptable range.

Link to the paper: The influence of instrumental line shape degradation on NDACC gas retrievals: total column and profile

Figure 1. Simulated ILS degradation with respect to different types of misalignment.
(Image by SUN Youwen)

Figure 2. Sensitivity of total column with respect to different levels of ILS degradation for all current standard NDACC gases.
(Image by SUN Youwen)

Contact:

ZHOU Shu

Hefei Institutes of Physical Science (http://english.hf.cas.cn/)

Email: zhous@hfcas.ac.cn