Coupling of Clouds and Tropospheric Relative Humidity in the Tropical Western Atlantic: Insights From Multisatellite Observations

Details

• Journal Title:
  Geophysical Research Letters
• Personal Author:
  Brogniez, Hélène ; Kirstetter, Pierre‐Emmanuel
• NOAA Program & Office:
  OAR (Oceanic and Atmospheric Research) ; NSSL (National Severe Storms Laboratory)
• Description:
  We investigated the interactions between clouds and moisture at the diurnal scale in the Western Atlantic trade winds region. Profiles of tropospheric relative humidity from theSAPHIR/Megha-Tropiques sounder are combined with cloud categories obtained from geostationary satellites. In winter, the midtroposphere undergoes strong daytime drying due to air masses coming from the colder upper troposphere. The moistening near the surface triggered by solar radiation precludes thedevelopment of low-level clouds. At night rising moist air in the upper troposphere triggers the formation of high-altitude clouds and favors their presence. In summer, daytime high-altitude clouds shield the solar forcing on the atmosphere and reduce drying from large-scale subsidence. After sunset, the developmentof upper tropospheric opaque clouds constitutes a local source of moisture. We argue that modulations of the diurnal cycle of clouds and relative humidity by season may be related to diurnal pulses of the
• Keywords:
  General Earth And Planetary Sciences Geophysics General Earth And Planetary Sciences General Earth And Planetary Sciences
• Source:
  Geophysical Research Letters, 47(7)
• DOI:
  https://doi.org/10.1029/2020gl087466
• ISSN:
  0094-8276 ; 1944-8007
• Format:
  PDF
• Publisher:
  American Geophysical Union (AGU)
• Document Type:
  Journal Article
• Rights Information:
  Other
• Compliance:
  Library
• Main Document Checksum:
  urn:sha256:a496a101858f24f94092bdde2037a8c48185d5ad4d867106db46ac651ad6377e
• Download URL:
  https://repository.library.noaa.gov/view/noaa/52709/noaa_52709_DS1.pdf
• File Type:
  [PDF - 11.44 MB ]