HR: 17:00h
AN: A24A-06    [Abstracts]
TI: Water Vapor, Cloud Liquid Water Paths, and Rain Rates over the Northern High Latitudes
AU: * Zuidema, P
EM: pzuidema@rsmas.miami.edu
AF: RSMAS/U of Miami, 4600 Rickenbacker Cswy, Miami, FL 33149, United States
AU: Joyce, R
EM: rjoyce@noaa.gov
AF: NOAA/NWS/NCEP/CPC, Camp Springs, Camp Springs, MA 33149, United States
AB: Data from the Special Sensor Microwave Imager (years 1987-2006), Advanced Microwave Scanning Radiometer, and a surface-based radiometer at Barrow, Alaska are examined for insights into the behavior of water vapor, cloud liquid water and rainrates over the northern high latitudes. Screening for sea ice is accomplished by combining an independent dataset of monthly-mean sea ice fractions with the water vapor path (WVP), cloud liquid water path (LWP), and rainrate (RR) retrievals. The Wentz water vapor path retrieval shows no sensitivity to a proxy for sub-pixel sea ice presence, while the Wentz liquid water path retrievals are sensitive to sea ice presence during summertime when atmospheric variability is high but otherwise their sea-ice screening appears effective. The rainrate retrieval is highly sensitive to sea ice. The seasonal cycle and 1987-2006 time trends are examined. The WVP annual cycle has an amplitude of 1 cm with a July maximum phasing that is consistent with a continental influence. The springtime LWP increase usually occurs in tandem with the WVP increase and slightly lags the falltime WVP decrease. The maximum lag occurs over the northern Pacific, where the maximum LWP occurs in August, one month later than over the northern Atlantic, and is correlated to an August precipitation maximum. The strongest SSMI-derived trend is an increase in wintertime moisture south and southwest of Greenland, consistent with continental air outflow over warmer waters. An interesting feature is an autumnal increase in WVP and LWP north of the Bering Strait from 1989 to 2001 with a subsequent decrease in recent years. This cannot be explained by surface evaporation off of increased areas of open water and instead appears linked to recent decreases in cyclone activity. Winter and spring increases in LWP are noted in the surface-based dataset from Barrow, Alaska.
DE: 1610 Atmosphere (0315, 0325)
DE: 1616 Climate variability (1635, 3305, 3309, 4215, 4513)
DE: 1635 Oceans (1616, 3305, 4215, 4513)
DE: 1855 Remote sensing (1640)
SC: Atmospheric Sciences [A]
MN: 2007 Fall Meeting