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Observing the timescales of aerosol–cloud interactions in snapshot satellite images
- Source :
- Atmospheric Chemistry and Physics, Vol 21, Pp 6093-6109 (2021)
- Publication Year :
- 2021
- Publisher :
- Copernicus Publications, 2021.
-
Abstract
- The response of cloud processes to an aerosol perturbation is one of the largest uncertainties in the anthropogenic forcing of the climate. It occurs at a variety of timescales, from the near-instantaneous Twomey effect to the longer timescales required for cloud adjustments. Understanding the temporal evolution of cloud properties following an aerosol perturbation is necessary to interpret the results of so-called “natural experiments” from a known aerosol source such as a ship or industrial site. This work uses reanalysis wind fields and ship emission information matched to observations of ship tracks to measure the timescales of cloud responses to aerosol in instantaneous (or“snapshot”) images taken by polar-orbiting satellites. As in previous studies, the local meteorological environment is shown to have a strong impact on the occurrence and properties of ship tracks, but there is a strong time dependence in their properties. The largest droplet number concentration (Nd) responses are found within 3 h of emission, while cloud adjustments continue to evolve over periods of 10 h or more. Cloud fraction is increased within the early life of ship tracks, with the formation of ship tracks in otherwise clear skies indicating that around 5 %–10 % of clear-sky cases in this region may be aerosol-limited. The liquid water path (LWP) enhancement and the Nd–LWP sensitivity are also time dependent and strong functions of the background cloud and meteorological state. The near-instant response of the LWP within ship tracks may be evidence of a bias in estimates of the LWP response to aerosol derived from natural experiments. These results highlight the importance of temporal development and the background cloud field for quantifying the aerosol impact on clouds, even in situations where the aerosol perturbation is clear.
- Subjects :
- Atmospheric Science
010504 meteorology & atmospheric sciences
Meteorology
Ship tracks
QC1-999
0211 other engineering and technologies
Perturbation (astronomy)
Cloud computing
Environmental Sciences & Ecology
02 engineering and technology
01 natural sciences
Snapshot (photography)
Aerosol cloud
0201 Astronomical and Space Sciences
Meteorology & Atmospheric Sciences
QD1-999
Physics::Atmospheric and Oceanic Physics
021101 geological & geomatics engineering
0105 earth and related environmental sciences
Remote sensing
Science & Technology
business.industry
Physics
Cloud fraction
aerosol–cloud interactions
Aerosol
Chemistry
13. Climate action
Physical Sciences
Environmental science
Liquid water path
Satellite
0401 Atmospheric Sciences
business
Twomey effect
Life Sciences & Biomedicine
Environmental Sciences
Subjects
Details
- Language :
- English
- ISSN :
- 16807324
- Database :
- OpenAIRE
- Journal :
- Atmospheric Chemistry and Physics, Vol 21, Pp 6093-6109 (2021)
- Accession number :
- edsair.doi.dedup.....49c7896824064d605878c639653ac9c6