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UID:20260203T053422EST-35813u1s8V@132.216.98.100
DTSTAMP:20260203T103422Z
DESCRIPTION:Cloud-assisted retrieval of stratospheric water vapor from nadi
 r view satellite measurements\n\n	Water vapor in dry atmospheric environmen
 ts is of great importance for weather and climate. For example\, despite o
 f its scarcity\, stratospheric water vapor is an important atmospheric com
 ponent that can greatly influence climate change\, due to its radiative an
 d chemical impacts. Recent studies suggest that stratospheric water vapor 
 may have strong relations to surface climate change and stratospheric ozon
 e loss\, highlighting the need of improved monitoring of stratospheric wat
 er vapor. However\, the retrieval of stratospheric water vapor is known to
  be challenging. Satellite nadir view radiance measurements usually do not
  have sufficient sensitivity to the low concentration of stratospheric wat
 er vapor while limb view measurements have large sampling footprints\, mak
 ing small scale water vapor hard to be detected.\n	This study tests the fea
 sibility of retrieving the stratospheric water vapor in the presence of de
 nse upper tropospheric clouds\, which block the radiance emission and obsc
 uration of the lower atmosphere for stratospheric retrieval. This investig
 ation uses synthetic satellite radiance simulated from atmospheric profile
 s using a radiative transfer model\, MODTRAN\, and adopts a widely-used op
 timal estimation method [Rodgers 2000] that iteratively retrieve the strat
 ospheric temperature and humidity.\n	We find the quality of retrieval resul
 ts depends on several factors. High spectral resolution and low level of m
 easurement noise are especially beneficial to the retrieval accuracy\, whi
 le the coverage of far infrared band is also critical. An ideal case is ab
 le to effectively reduce 44% uncertainty for specific humidity\, and impro
 ve 55% of accuracy for column integrated water vapor in the lower stratosp
 here. \n\n
DTSTART:20161019T183000Z
DTEND:20161019T193000Z
LOCATION:Room 934\, Burnside Hall\, CA\, QC\, Montreal\, H3A 0B9\, 805 rue 
 Sherbrooke Ouest
SUMMARY:Student Seminar: Jing Feng
URL:/channels/event/student-seminar-jing-feng-262517
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