Assessing the Ability of IR Sounders to Detect Atmospheric Rivers and Related Extreme Flooding Events

Abstract:

The IPCC 5^th Assessment found that extreme precipitation events over most mid-latitude land masses is very likely (> 90%) to become more intense and frequent. Atmospheric Rivers (ARs) transport large amounts of water vapor and can lead to major flooding evens when they make land fall. Precipitable Water Vapor (PWV) is defined as the amount of liquid water that would be produced if all of the water vapor in an atmospheric column were condensed and is a useful parameter to determine atmospheric stability and the probability of convection and severe weather. The Atmospheric Infrared Sounder (AIRS) on the NASA Aqua satellite was the first of a new generation of satellite sensors that provided the capability to retrieve water vapor profiles at high vertical resolution and good absolute accuracy over both ocean and land areas using the same algorithm. The operational follow-on to the AIRS is the Cross-track Infrared Sounder (CrIS) successfully launched on the Suomi NPP satellite on 28 October 2011. The CrIS, along with ATMS, will provide the U.S. component of the joint U.S./European operational weather satellite system. The Infrared Atmospheric Sounding Interferometer (IASI) was launched on METOP-A in October 2006 and is currently operated by EUMETSAT. This paper investigates the ability of PWV from IR sounders to capture ARs. Results are presented that highlight the extreme moisture transport from ARs during case-study flooding events. Differences and agreements between satellite retrievals and NWP reanalysis will identified.