A new airborne laser-induced fluorescence instrument for in situ detection of formaldehyde throughout the troposphere and lower stratosphere
M. Cazorla1,*,G. M. Wolfe1,2,S. A. Bailey1,A. K. Swanson1,3,H. L. Arkinson4,and T. F. Hanisco1M. Cazorla et al.M. Cazorla1,*,G. M. Wolfe1,2,S. A. Bailey1,A. K. Swanson1,3,H. L. Arkinson4,and T. F. Hanisco1
1Atmospheric Chemistry and Dynamics Lab, NASA Goddard Space Flight Center, Greenbelt, MD, USA
2Joint Center for Earth Systems Technology, University of Maryland Baltimore County, Baltimore, MD, USA
3Goddard Earth Sciences Technology and Research, University of Maryland Baltimore County, Baltimore, MD, USA
4Department of Atmospheric and Oceanic Science, University of Maryland, College Park, MD, USA
*now at: Universidad San Francisco de Quito, Instituto de Investigaciones Atmosféricas, Colegio de Ciencias e Ingeniería, Diego de Robles y Vía Interoceánica, Quito, Ecuador
1Atmospheric Chemistry and Dynamics Lab, NASA Goddard Space Flight Center, Greenbelt, MD, USA
2Joint Center for Earth Systems Technology, University of Maryland Baltimore County, Baltimore, MD, USA
3Goddard Earth Sciences Technology and Research, University of Maryland Baltimore County, Baltimore, MD, USA
4Department of Atmospheric and Oceanic Science, University of Maryland, College Park, MD, USA
*now at: Universidad San Francisco de Quito, Instituto de Investigaciones Atmosféricas, Colegio de Ciencias e Ingeniería, Diego de Robles y Vía Interoceánica, Quito, Ecuador
Correspondence: T. F. Hanisco (thomas.hanisco@nasa.gov)
Received: 21 Jul 2014 – Discussion started: 19 Aug 2014 – Revised: 13 Nov 2014 – Accepted: 09 Dec 2014 – Published: 03 Feb 2015
Abstract. The NASA In Situ Airborne Formaldehyde (ISAF) instrument is a high-performance laser-based detector for gas-phase formaldehyde (HCHO). ISAF uses rotational-state specific laser excitation at 353 nm for laser-induced fluorescence (LIF) detection of HCHO. A number of features make ISAF ideal for airborne deployment, including (1) a compact, low-maintenance fiber laser, (2) a single-pass design for stable signal response, (3) a straightforward inlet design, and (4) a stand-alone data acquisition system. A full description of the instrument design is given, along with detailed performance characteristics. The accuracy of reported mixing ratios is ±10% based on calibration against IR and UV absorption of a primary HCHO standard. Precision at 1 Hz is typically better than 20% above 100 pptv, with uncertainty in the signal background contributing most to variability at low mixing ratios. The 1 Hz detection limit for a signal / noise ratio of 2 is 36 pptv for 10 mW of laser power, and the e fold time response at typical sample flow rates is 0.19 s. ISAF has already flown on several field missions and platforms with excellent results.
We present a description of a new instrument designed to detect formaldehyde (HCHO) in situ on airborne platforms. The instrument combines state-of-the art laser technology with single-photon counting detection to provide unmatched performance in a small autonomous package. The development of this In Situ Airbornes Formaldehyde (ISAF) instrument provides a significant new capability for NASA’s high altitude aircraft that requires little space and provides ultra-sensitive detection.
We present a description of a new instrument designed to detect formaldehyde (HCHO) in situ on...
