Public Abstract

DE-SC0025204: Connecting Aerosol-Related Cloud Brightness to Turbulence using EPCAPE Measurements

Award Status: Active

Institution: Rutgers, The State University of New Jersey, Piscataway, NJ
UEI: M1LVPE5GLSD9
DUNS: 001912864

Most Recent Award Date: 08/19/2024
Number of Support Periods: 1
PM: Stehr, Jeffrey

Current Budget Period: 09/01/2024 - 02/28/2026
Current Project Period: 09/01/2024 - 08/31/2027
PI: Miller, Mark

Supplement Budget Period: N/A

Public Abstract

Connecting Aerosol-Related Cloud Brightness to Turbulence using EPCAPE Measurements Principal Investigator: Mark Miller Co-Investigators: Lynn Russell and Dan Lubin (University of California-San Diego/Scripps Institution of Oceanography) Unfunded collaborators: Rachel Chang (Dalhousie University), The lower part of the atmosphere above the ocean surface, which is known as the marine boundary layer (MBL), is home to shallow, layered clouds known as marine stratocumulus. Marine stratocumulus clouds cover a substantial portion of the global oceans, but their structure is often modified at coastal boundaries. Together marine and coastal clouds are a major contributor to the planetary energy budget because they influence the amount of sunlight that is transmitted to the ocean surface. Therefore, they must be accurately represented in weather forecast and global climate models to predict changes in over-ocean and coastal cloud cover. The amount of sunlight that is redirected to space by marine stratocumulus clouds, known as the cloud albedo, is sensitive to tiny, microscopic particles in the atmosphere known as aerosols and to the turbulent air movements inside the clouds. Together, aerosols and in-cloud turbulence control the size and number of cloud droplets. These aerosol-cloud interactions (ACI) are complex, and under certain conditions ACI can create large populations of small cloud droplets that increase cloud albedo, a process known as cloud brightening. This study focuses on the processes that play a key role in modulating cloud brightening. We are using a combination of measurements from the Eastern Pacific Cloud Aerosol and Precipitation Experiment (EPCAPE) to understand how turbulent fluctuations of air inside the cloud along with the in-cloud processing of aerosols conspire to change cloud brightness. We hypothesize that aerosols control cloud brightness in some conditions, while turbulent updrafts in the clouds control cloud brightness in other conditions. We expect our research to provide guidance that may be useful in characterizing the changes in cloud brightening due to ACI that are caused by alterations in the underlying aerosol structure or alterations in the in-cloud turbulence, or both.

Connecting Aerosol-Related Cloud Brightness to Turbulence using EPCAPE Measurements
Principal Investigator: Mark Miller
Co-Investigators: Lynn Russell and Dan Lubin (University of California-San Diego/Scripps Institution of Oceanography)
Unfunded collaborators: Rachel Chang (Dalhousie University),

The lower part of the atmosphere above the ocean surface, which is known as the marine boundary layer (MBL), is home to shallow, layered clouds known as marine stratocumulus. Marine stratocumulus clouds cover a substantial portion of the global oceans, but their structure is often modified at coastal boundaries. Together marine and coastal clouds are a major contributor to the planetary energy budget because they influence the amount of sunlight that is transmitted to the ocean surface. Therefore, they must be accurately represented in weather forecast and global climate models to predict changes in over-ocean and coastal cloud cover. The amount of sunlight that is redirected to space by marine stratocumulus clouds, known as the cloud albedo, is sensitive to tiny, microscopic particles in the atmosphere known as aerosols and to the turbulent air movements inside the clouds. Together, aerosols and in-cloud turbulence control the size and number of cloud droplets. These aerosol-cloud interactions (ACI) are complex, and under certain conditions ACI can create large populations of small cloud droplets that increase cloud albedo, a process known as cloud brightening. This study focuses on the processes that play a key role in modulating cloud brightening. We are using a combination of measurements from the Eastern Pacific Cloud Aerosol and Precipitation Experiment (EPCAPE) to understand how turbulent fluctuations of air inside the cloud along with the in-cloud processing of aerosols conspire to change cloud brightness. We hypothesize that aerosols control cloud brightness in some conditions, while turbulent updrafts in the clouds control cloud brightness in other conditions. We expect our research to provide guidance that may be useful in characterizing the changes in cloud brightening due to ACI that are caused by alterations in the underlying aerosol structure or alterations in the in-cloud turbulence, or both.