Search Results

You are looking at 1 - 3 of 3 items for

  • Author or Editor: John Shilling x
  • Refine by Access: All Content x
Clear All Modify Search
James Mather, Susannah Burrows, Duli Chand, Nancy Hess, Alexander Laskin, Allison McComiskey, Noopur Sharma, and John Shilling
Full access
Jerome D. Fast, Larry K. Berg, Lizbeth Alexander, David Bell, Emma D’Ambro, John Hubbe, Chongai Kuang, Jiumeng Liu, Chuck Long, Alyssa Matthews, Fan Mei, Rob Newsom, Mikhail Pekour, Tamara Pinterich, Beat Schmid, Siegfried Schobesberger, John Shilling, James N. Smith, Stephen Springston, Kaitlyn Suski, Joel A. Thornton, Jason Tomlinson, Jian Wang, Heng Xiao, and Alla Zelenyuk

Abstract

Shallow convective clouds are common, occurring over many areas of the world, and are an important component in the atmospheric radiation budget. In addition to synoptic and mesoscale meteorological conditions, land–atmosphere interactions and aerosol–radiation–cloud interactions can influence the formation of shallow clouds and their properties. These processes exhibit large spatial and temporal variability and occur at the subgrid scale for all current climate, operational forecast, and cloud-system-resolving models; therefore, they must be represented by parameterizations. Uncertainties in shallow cloud parameterization predictions arise from many sources, including insufficient coincident data needed to adequately represent the coupling of cloud macrophysical and microphysical properties with inhomogeneity in the surface-layer, boundary layer, and aerosol properties. Predictions of the transition of shallow to deep convection and the onset of precipitation are also affected by errors in simulated shallow clouds. Coincident data are a key factor needed to achieve a more complete understanding of the life cycle of shallow convective clouds and to develop improved model parameterizations. To address these issues, the Holistic Interactions of Shallow Clouds, Aerosols and Land Ecosystems (HI-SCALE) campaign was conducted near the Atmospheric Radiation Measurement (ARM) Southern Great Plains site in north-central Oklahoma during the spring and summer of 2016. We describe the scientific objectives of HI-SCALE as well as the experimental approach, overall weather conditions during the campaign, and preliminary findings from the measurements. Finally, we discuss scientific gaps in our understanding of shallow clouds that can be addressed by analysis and modeling studies that use HI-SCALE data.

Open access
Jian Wang, Rob Wood, Michael P. Jensen, J. Christine Chiu, Yangang Liu, Katia Lamer, Neel Desai, Scott E. Giangrande, Daniel A. Knopf, Pavlos Kollias, Alexander Laskin, Xiaohong Liu, Chunsong Lu, David Mechem, Fan Mei, Mariusz Starzec, Jason Tomlinson, Yang Wang, Seong Soo Yum, Guangjie Zheng, Allison C. Aiken, Eduardo B. Azevedo, Yann Blanchard, Swarup China, Xiquan Dong, Francesca Gallo, Sinan Gao, Virendra P. Ghate, Susanne Glienke, Lexie Goldberger, Joseph C. Hardin, Chongai Kuang, Edward P. Luke, Alyssa A. Matthews, Mark A. Miller, Ryan Moffet, Mikhail Pekour, Beat Schmid, Arthur J. Sedlacek, Raymond A. Shaw, John E. Shilling, Amy Sullivan, Kaitlyn Suski, Daniel P. Veghte, Rodney Weber, Matt Wyant, Jaemin Yeom, Maria Zawadowicz, and Zhibo Zhang

Abstract

With their extensive coverage, marine low clouds greatly impact global climate. Presently, marine low clouds are poorly represented in global climate models, and the response of marine low clouds to changes in atmospheric greenhouse gases and aerosols remains the major source of uncertainty in climate simulations. The Eastern North Atlantic (ENA) is a region of persistent but diverse subtropical marine boundary layer clouds, whose albedo and precipitation are highly susceptible to perturbations in aerosol properties. In addition, the ENA is periodically impacted by continental aerosols, making it an excellent location to study the cloud condensation nuclei (CCN) budget in a remote marine region periodically perturbed by anthropogenic emissions, and to investigate the impacts of long-range transport of aerosols on remote marine clouds. The Aerosol and Cloud Experiments in Eastern North Atlantic (ACE-ENA) campaign was motivated by the need of comprehensive in-situ measurements for improving the understanding of marine boundary layer CCN budget, cloud and drizzle microphysics, and the impact of aerosol on marine low cloud and precipitation. The airborne deployments took place from June 21 to July 20, 2017 and January 15 to February 18, 2018 in the Azores. The flights were designed to maximize the synergy between in-situ airborne measurements and ongoing long-term observations at a ground site. Here we present measurements, observation strategy, meteorological conditions during the campaign, and preliminary findings. Finally, we discuss future analyses and modeling studies that improve the understanding and representation of marine boundary layer aerosols, clouds, precipitation, and the interactions among them.

Full access