2008 VAMOS Ocean-Cloud-Atmos-Land Study (VOCALS)

14 October 2008 - 13 November 2008

Lead Scientist: Peter Daum

Observatory: osc, osc

The DOE G-1 aircraft was deployed to Arica, Chile as part of the NSF VAMOS Ocean-Cloud- Atmospheric-Land Study (VOCALS). The purpose of VOCALS is to develop an understanding of the physical and chemical processes central to the climate system of the Southeast Pacific. In this region, extensive areas of marine clouds exist (coverage about 70% in October). The ASP component of VOCALS focused on aerosols, and how their chemical and microphysical properties, and their ability to act as CCN differ between remote marine air masses and marine air masses that have been influenced to varying degrees by anthropogenic aerosols, and how these differences in aerosol properties influence the microphysical properties of the clouds that form in these different environments. The NSF C-130 aircraft and the NOAA R/V Ronald H. Brown also collected data in the region during the G-1 flights.

The data collected during this field campaign allow examination of the relationship between aerosol composition, size, and CCN activity; between CCN loading and activity and cloud droplet microphysics; between cloud droplet microphysics and cloud radiative properties (first indirect effect studies); and between cloud droplet microphysics and the formation of drizzle (second indirect aerosol effect studies). Data can also be used to examine the validity of recently developed parameterizations of cloud microphysical processes and the properties designed for use in GCMs, and to develop the physical insight needed to develop more complete and sophisticated parameterizations of these quantities.

The G-1 was instrumented with its standard suite for meteorology/state parameters. Additional instrumentation allowed characterization of the chemical and microphysical properties of aerosols and the microphysical properties of clouds. Trace-gas instrumentation measured aerosol precursors (SO_2 and DMS) and species that aid in estimating anthropogenic contributions to aerosols (CO and O_3 ) in the air masses being sampled. Aerosol optical properties (absorbance and scattering), size distributions and concentrations of aerosols and clouds, aerosol chemical composition and cloud forming tendencies were all measured using a suite of research grade instruments modified for aircraft operations. Flights included below-cloud legs to measure pre-cloud aerosol properties, in-cloud flights at several altitudes to examine the relationships between pre-cloud aerosol properties, cloud dynamics and cloud droplet microphysics, and their variation with altitude, and sampling through and above cloud top to define the vertical dimensions of the cloud, to document the thermodynamic structure of the atmosphere, and to sample the properties of the above-cloud aerosols.


Larry Kleinman Robert McGraw Jian Wang
Yin-Nan Lee Gunnar Senum
Yangang Liu Stephen Springston


Vivekanandan J, V Ghate, J Jensen, S Ellis, and M Schwartz. 2020. "A Technique for Estimating Liquid Droplet Diameter and Liquid Water Content in Stratocumulus Clouds Using Radar and Lidar Measurements." Journal of Atmospheric and Oceanic Technology, , 10.1175/JTECH-D-19-0092.1. ONLINE.

Johnson J, L Regayre, M Yoshioka, K Pringle, S Turnock, J Browse, D Sexton, J Rostron, N Schutgens, D Partridge, D Liu, J Allan, H Coe, A Ding, D Cohen, A Atanacio, V Vakkari, E Asmi, and K Carslaw. 2020. "Robust observational constraint of uncertain aerosol processes and emissions in a climate model and the effect on aerosol radiative forcing." Atmospheric Chemistry and Physics, 20(15), 10.5194/acp-20-9491-2020.

Kazimirad M and M Miller. 2020. "Summertime Post-Cold-Frontal Marine Stratocumulus Transition Processes over the Eastern North Atlantic." Journal of the Atmospheric Sciences, 77(6), 10.1175/JAS-D-19-0167.1.
Research Highlight


Zhang C, Y Wang, and M Xue. 2019. " Evaluation of an -ε and three other Boundary Layer Parameterization Schemes in the WRF Model over the Southeast Pacific and the Southern Great Plains ." Monthly Weather Review, 148(3), 10.1175/MWR-D-19-0084.1.

Zhang D, A Vogelmann, P Kollias, E Luke, F Yang, D Lubin, and Z Wang. 2019. "Comparison of Antarctic and Arctic Single‐Layer Stratiform Mixed‐Phase Cloud Properties Using Ground‐Based Remote Sensing Measurements." Journal of Geophysical Research: Atmospheres, 124(17-18), 10.1029/2019JD030673.
Research Highlight

Liu Y. 2019. "Introduction to the Special Section on Fast Physics in Climate Models: Parameterization, Evaluation, and Observation." Journal of Geophysical Research: Atmospheres, 124(15), 10.1029/2019JD030422.

Jia H, X Ma, and Y Liu. 2019. "Exploring aerosol–cloud interaction using VOCALS-REx aircraft measurements." Atmospheric Chemistry and Physics, 19(12), 10.5194/acp-19-7955-2019.

Zheng Y, D Rosenfeld, Y Zhu, and Z Li. 2019. "Satellite‐Based Estimation of Cloud Top Radiative Cooling Rate for Marine Stratocumulus." Geophysical Research Letters, 46(8), 10.1029/2019GL082094.
Research Highlight


Grosvenor D, O Sourdeval, P Zuidema, A Ackerman, M Alexandrov, R Bennartz, R Boers, B Cairns, J Chiu, M Christensen, H Deneke, M Diamond, G Feingold, A Fridlind, A Hünerbein, C Knist, P Kollias, A Marshak, D McCoy, D Merk, D Painemal, J Rausch, D Rosenfeld, H Russchenberg, P Seifert, K Sinclair, P Stier, B van Diedenhoven, M Wendisch, F Werner, R Wood, Z Zhang, and J Quaas. 2018. "Remote Sensing of Droplet Number Concentration in Warm Clouds: A Review of the Current State of Knowledge and Perspectives." Reviews of Geophysics, 56(2), 10.1029/2017RG000593.

de Szoeke S, K Verlinden, and D Covert. 2018. "Cloud-Scale Droplet Number Sensitivity to Liquid Water Path in Marine Stratocumulus." Journal of Geophysical Research: Atmospheres, 123(10), 10.1029/2017JD027508.

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Campaign Data Sets

IOP Participant Data Source Name Final Data
John Hubbe GPS Order Data
John Hubbe Nephelometer Order Data
John Hubbe Particle Soot Absorption Photometer - G1 Aircraft Order Data
John Hubbe Time of Flight Aerosol Mass Spectrometer Order Data
Alexander Laskin Time Resolved Aerosol Collectors (AOS inlet) Order Data
Yin-Nan Lee Particle-Into-Liquid Sampler (PILS) Order Data
Gunnar Senum Cloud Aerosol Precip Spectrometer(CAPS)/Cloud Imaging Probe (CIP) Order Data
Gunnar Senum Cloud and Aerosol Spectrometer Order Data
Gunnar Senum Gust Probe Order Data
Gunnar Senum Liquid Water Content (pvm-100a probe, SEA WCM-2000) Order Data
Gunnar Senum Passive Cavity Aerosol Spectrometer Order Data
Stephen Springston Accelerometer- G1 Aircraft Order Data
Stephen Springston Carbon Monoxide and Nitrous Oxide Order Data
Stephen Springston Met Order Data
Stephen Springston Ozone Order Data
Jian Wang Cloud Condensation Nuclei Counter- T1 Site Order Data
Jian Wang Scanning mobility particle sizer Order Data