Atmospheric Radiation Measurement Climate Research Facility US Department of Energy



Cloud And Precipitation Experiment at kennaook

15 April 2024 - 15 September 2025

Lead Scientist: Gerald Mace

Observatory: amf, kcg

The Kennaook/Cape Grim Baseline Air Pollution Station (KCGBAPS) on the northwestern tip of Tasmania, Australia (40.68o S, 144.69oE) is a Global Atmospheric Watch Station that has collected the longest and most consequential record of atmospheric composition in the Southern Hemisphere, now spanning more than four decades. The air masses that pass over KCGBAPS frequently originate from the high-latitude Southern Ocean and are essentially devoid of anthropogenic or even continental influence. The Cloud And Precipitation Experiment at kennaook (CAPE-k) will augment the ongoing measurements at KCGBAPS with components of the second ARM Mobile Facility (AMF2) and will provide cloud and precipitation observations from a suite of ground-based remote sensors from mid-April 2024 through September 2025. CAPE-k is motivated by ongoing challenges in simulating clouds and precipitation over the Southern Ocean (SO), a region where there are strong and highly uncertain latitudinal gradients in cloud radiative effects and cloud feedbacks.

Primary science objectives of CAPE-k are to:

1. Document the seasonal cycle of SO low-cloud and precipitation properties and examine how they co-vary with aerosol and with dynamical and thermodynamical factors.

2. Compare and contrast these relationships with observations from other surface sites and campaigns, including other ARM sites and ARM-supported campaigns.

3. Study aerosol-cloud-precipitation interactions in pristine marine low clouds and explore how these interactions can best be represented in models at various scales.

Pursuit of these objectives will be facilitated by the deployment of AMF2 aerosol and cloud instruments to the KCGBAPS site, which will include vertically pointing millimeter-wavelength cloud radar, lidar, and passive radiometry. Exploiting a long-established collaboration between ARM, ARM scientists, and our valued Australian colleagues, CAPE-k will allow for creation of an unprecedented record of aerosol-cloud-precipitation interaction in the maritime Southern Hemisphere midlatitudes.


Yi Huang Po-Lun Ma Christina McCluskey
Ruhi Humphries Roger Marchand Alain Protat
Melita Keywood Peter May Steven Siems


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