Abstract
A tethered balloon system (TBS) has been developed and is being operated by Sandia National Laboratories (SNL) on behalf of the U.S. Department of Energy’s (DOE) Atmospheric Radiation Measurement (ARM) User Facility in order to collect in situ atmospheric measurements within mixed-phase Arctic clouds. Periodic tethered balloon flights have been conducted since 2015 within restricted airspace at ARM’s Advanced Mobile Facility 3 (AMF3) in Oliktok Point, Alaska, as part of the AALCO (Aerial Assessment of Liquid in Clouds at Oliktok), ERASMUS (Evaluation of Routine Atmospheric Sounding Measurements using Unmanned Systems), and POPEYE (Profiling at Oliktok Point to Enhance YOPP Experiments) field campaigns. The tethered balloon system uses helium-filled 34 m3 helikites and 79 and 104 m3 aerostats to suspend instrumentation that is used to measure aerosol particle size distributions, temperature, horizontal wind, pressure, relative humidity, turbulence, and cloud particle properties and to calibrate ground-based remote sensing instruments.
Supercooled liquid water content (SLWC) sondes using the vibrating wire principle, developed by Anasphere Inc., were operated at Oliktok Point at multiple altitudes on the TBS within mixed-phase clouds for over 200 hours Sonde-collected SLWC data were compared with liquid water content derived from a microwave radiometer, Ka-band ARM Zenith radar, and ceilometer at the AMF3, as well as liquid water content derived from AMF3 radiosonde flights. The in situ data collected by the Anasphere sensors were also compared with data collected simultaneously by an alternative SLWC sensor developed at the University of Reading, UK; both vibrating wire instruments were typically observed to shed their ice quickly upon exiting the cloud or reaching maximum ice loading. Tethered balloon fiber optic distributed temperature sensing measurements were also compared with AMF3 radiosonde temperature measurements. Combined, the results indicate that TBS distributed temperature sensing and supercooled liquid water measurements are in reasonably good agreement with remote-sensing and radiosonde-based measurements of both properties. From these measurements and sensor evaluations, tethered balloon flights are shown to offer an effective method of collecting data to inform and constrain numerical models, calibrate and validate remote sensing instruments, and characterize the flight environment of unmanned aircraft, circumventing the difficulties of in-cloud unmanned aircraft flights such as limited flight time and in-flight icing.
Supercooled liquid water content (SLWC) sondes using the vibrating wire principle, developed by Anasphere Inc., were operated at Oliktok Point at multiple altitudes on the TBS within mixed-phase clouds for over 200 hours Sonde-collected SLWC data were compared with liquid water content derived from a microwave radiometer, Ka-band ARM Zenith radar, and ceilometer at the AMF3, as well as liquid water content derived from AMF3 radiosonde flights. The in situ data collected by the Anasphere sensors were also compared with data collected simultaneously by an alternative SLWC sensor developed at the University of Reading, UK; both vibrating wire instruments were typically observed to shed their ice quickly upon exiting the cloud or reaching maximum ice loading. Tethered balloon fiber optic distributed temperature sensing measurements were also compared with AMF3 radiosonde temperature measurements. Combined, the results indicate that TBS distributed temperature sensing and supercooled liquid water measurements are in reasonably good agreement with remote-sensing and radiosonde-based measurements of both properties. From these measurements and sensor evaluations, tethered balloon flights are shown to offer an effective method of collecting data to inform and constrain numerical models, calibrate and validate remote sensing instruments, and characterize the flight environment of unmanned aircraft, circumventing the difficulties of in-cloud unmanned aircraft flights such as limited flight time and in-flight icing.
| Original language | English |
|---|---|
| Pages (from-to) | 6845-6864 |
| Number of pages | 20 |
| Journal | Atmospheric Measurement Techniques |
| Volume | 12 |
| Issue number | 12 |
| DOIs | |
| Publication status | Published - 20 Dec 2019 |
Bibliographical note
Funding Information:Acknowledgements. We gratefully acknowledge the U.S. Department of Energy Atmospheric Radiation Measurement program and Sandia National Laboratories for logistics support. This work was supported in part by the Laboratory Directed Research and Development program at Sandia National Laboratories, a multi-mission laboratory managed and operated by National Technology and Engineering Solutions of Sandia, LLC., a wholly owned subsidiary of Honeywell International Inc., for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-NA0003525. MA, KN, RGH, PDW, and GM acknowledge support from NERC grant no. NE/P003362/1 (VOLCLAB) for development of the Reading SLWC sensor. KN acknowledges support through the NERC Environmental Bioinformatics Centre (grant nos. NE/L011514/1, NE/L011514/2). SK was supported by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under grant KN 1112/2-1 as part of the Emmy-Noether Group OPTIMIce.
Funding Information:
The authors wish to thank Gijs de Boer for leading the ARM ICARUS and POPEYE field campaigns. John Shewchuk of Eosonde Research Services provided documentation regarding RAOB software calculations. John Bognar of Anasphere aided in the development of the SLWC Anasphere sonde data processing methodology. David Serke of UCAR provided guidance regarding the collection of SLWC data in flight. Allen Jordan and Emrys Hall of NOAA developed the SkySonde software for iMet radiosondes that was used to collect all iMet radiosonde-derived data used in this research. We thank CTEMPs, funded by the National Science Foundation (EAR awards 1440596 and 1440506), for providing initial training on the use of DTS and DTS data processing. Mark Benoit of InterMet provided technical support regarding iMet radiosondes and XQ2 sensors.
Publisher Copyright:
© 2019 Copernicus GmbH. All rights reserved.
ASJC Scopus subject areas
- Atmospheric Science