Aerosol, Cloud, Convection and Precipitation (ACCP)

Interactions between aerosols, cloud particles, precipitation, and radiation are central to understanding and predicting weather and severe storm development, air quality, and climate change. Key to ACCP science is that virtually every cloud particle, raindrop and snowflake is born from an aerosol particle, which intimately links aerosol and cloud/precipitation processes.


The ACCP Study will examine the linkages among aerosols, clouds, convection and precipitation by creating mission architectures that address Aerosol and CCP objectives simultaneously.




Multi-Center Architecture Study

  • NASA Headquarters
  • Ames Research Center  
  • Glenn Research Center
  • Goddard Space Flight Center
  • Jet Propulsion Laboratory
  • Langley Research Center
  • Marshall Space Flight Center

Meet the Team

The National Academies of Sciences, Engineering and Medicine (NASEM) 2017 Decadal Survey, “Thriving on Our Changing Planet: A Decadal Strategy for Earth Observations from Space,” identified five designated foundational observations to be implemented in the next decade. The ACCP Study is concerned with two of these Designated Observables (DO): 1) Aerosols and 2) Clouds, Convection and Precipitation (CCP).  The primary goal of the ACCP study is to define science objectives for these DOs and explore observing system architectures capable of addressing these science objectives. This study leverages results from historical studies and investments such as the Aerosol-Cloud-ocean Ecosystems (ACE) study, those from existing and proposed Earth Venture concepts, analyses already conducted on data from past field experiments, and recent advances of modeling systems and Observing System Simulation Experiments (OSSEs).

Given the synergisms among Aerosols, Clouds Convection and Precipitation in the Earth system, the ACCP Study team recognized the science merit in exploring a combined measurement system that addresses both Aerosol and CCP science questions, and enables an assessment of aerosol effects on clouds and precipitation and vice-versa. Based on the 2017 Decadal Survey, the ACCP Study focuses on the following measurements and broad scientific goals:

  • Aerosol:  Aerosol properties, aerosol vertical profiles, and cloud properties to understand their effects on climate and air quality
  • Clouds, Convection, and Precipitation (CCP):  Coupled cloud-precipitation states and dynamics for monitoring the global hydrological cycle and understanding contributing processes, including cloud feedback

More specifically, the ACCP Study focuses on science goals that trace back to most- and very-important Science Goals articulated in the 2017 Decadal Survey:

  • Cloud Feedbacks - Reduce the uncertainty in low- and high-cloud climate feedbacks by advancing our ability to predict the properties of low and high clouds.  
  • Storm Dynamics - Improve our physical understanding and model representations of cloud, precipitation and dynamical processes within storms. 
  • Cold Cloud and Precipitation - Improve understanding of cold (supercooled liquid, ice, and mixed phase) cloud processes and associated precipitation and their coupling to the surface at mid to high latitudes and to the cryosphere.
  • Aerosol Processes - Reduce uncertainty in key processes that link aerosols to weather, climate and air quality related impacts.
  • Aerosol Impacts on Radiation - Reduce the uncertainty in Direct (D) and Indirect (I) aerosol-related radiative forcing of the climate system.