Intercomparison of Two Hydroxyl Radical Measurement Techniques at the Atmosphere Simulation Chamber SAPHIR |
| |
| Authors: | Eric Schlosser Birger Bohn Theo Brauers Hans-Peter Dorn Hendrik Fuchs Rolf Häseler Andreas Hofzumahaus Frank Holland Franz Rohrer Lutz Olaf Rupp Manfred Siese Ralf Tillmann Andreas Wahner |
| |
| Institution: | 1. Institut für Chemie und Dynamik der Geosph?re II: Troposph?re, Forschungszentrum Jülich, 52425, Jülich, Germany
|
| |
| Abstract: | At the atmosphere simulation chamber SAPHIR in Jülich both Laser-Induced Fluorescence Spectroscopy (LIF) and Long-Path Differential
Optical Laser Absorption Spectroscopy (DOAS) are operational for the detection of OH radicals at tropospheric levels. The
two different spectroscopic techniques were compared within the controlled environment of SAPHIR based on all simultaneous
measurements acquired in 2003 (13 days). Hydroxyl radicals were scavenged by added CO during four of these days in order to
experimentally check the calculated precisions at the detection limit. LIF measurements have a higher precision (σ= 0.88×106 cm–3) and better time resolution (Δt = 60 s), but the DOAS method (σ= 1.24×106 cm–3, Δt = 135 s) is regarded as primary standard for comparisons because of its good accuracy. A high correlation coefficient of
r = 0.95 was found for the whole data set highlighting the advantage of using a simulation chamber. The data set consists of
two groups. The first one includes 3 days, where the LIF measurements yield (1 – 2) ×106 cm–3 higher OH concentrations than observed by the DOAS instrument. The experimental conditions during these days are characterized
by increased NOx concentration and a small dynamic range in OH. Excellent agreement is found within the other group of 6 days. The regression
to the combined data of this large group yields unity slope without a significant offset. |
| |
| Keywords: | atmosphere simulation chamber hydroxyl radical instrument intercomparison |
| 本文献已被 SpringerLink 等数据库收录！ |
