Project Details
Projekt
Highly sensitive and selective measurements of NO2 on HALO
Applicant
Dr. Monica Martinez-Harder
Subject Area
Atmospheric Science
Term
from 2010 to 2015
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 179857398
For the assessment of the photochemical processing that occurs in an air mass, highsensitivity measurements of reactive nitrogen species are a necessity. While in Germany a few groups have the capability to measure NO in the low ppt range, the capability for direct measurements of NO2 with this sensitivity is still missing (also in Europe). NO2 is mostly measured only indirectly via conversion to NO. Hereby the possibility that other nitrogen compounds are also converted to NO causing interferences can never be completely excluded. Laser-induced fluorescence (LIF) has already been demonstrated to detect NO2 directly and with high selectivity, reaching detection limits down to 5 ppt/min. This however required the use of large and expensive laser systems. Recently, diode lasers have become available emitting blue light, tunable in the wavelength range where the NO2 absorption is strongest, which will make it possible to build a much more compact and still highly sensitive LIF instrument to detect NO2. We have already developed a prototype and propose to complete the development of an instrument suitable to selectively measure NO2 on HALO with the required sensitivity. We are already involved in the OMO campaign planned to take place in summer 2011 with our LIF instrument to measure OH and HO2. The instrument for NO2 proposed here can be integrated into our HOX LIF, allowing additional measurements of NO2 without adding significantly to space, weight and power requirements on any HALO mission where our HOX measurements are included.
DFG Programme
Infrastructure Priority Programmes
