Instrumentation needs and capabilities for water isotopologue measurements in cold clouds
Abstract
Recent advances in spectroscopic instrumentation have opened pathways for using observations of water isotopic composition to study microphysics within cold clouds. We discuss here instrumentation requirements for the use of water isotopologue measurements in laboratory and field studies of three microphysical problems: characterizing glaciation in mixed-phase clouds, observing moisture recycling in long-lived cirrus, and diagnosing growth limitation in ultra-cold cirrus. We show how techniques such as isotopic doping and low-ppm calibration can bring relevant science within reach of non-cavity-based absorption spectroscopy in laboratory studies such as the ongoing ISOCLOUD campaign at AIDA. Calibration is especially challenging in water isotopologue science and ultimately limits measurement accuracy even in air at low altitude and high water vapor concentration. We show a new system for producing calibration air streams of known water vapor content and isotopic composition and demonstrate that it achieves the stability needed to enable science-quality measurements.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2012
- Bibcode:
- 2012AGUFM.A13H0288S
- Keywords:
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- 0320 ATMOSPHERIC COMPOSITION AND STRUCTURE / Cloud physics and chemistry;
- 0394 ATMOSPHERIC COMPOSITION AND STRUCTURE / Instruments and techniques;
- 3311 ATMOSPHERIC PROCESSES / Clouds and aerosols;
- 3394 ATMOSPHERIC PROCESSES / Instruments and techniques