Extreme Outliers in Lower Stratospheric Water Vapor Over North America Observed by MLS: Relation to Overshooting Convection Diagnosed From Colocated Aqua-MODIS Data.

ABSTRACT: Convectively injected water vapor (H₂O) in the North American (NA) summer lowermost stratosphere results in significant outliers in the 100-hPa H₂O measurements from the Aura Microwave Limb Sounder (MLS). MLS statistics from 15 years confirm that the NA region contains over 60% of global 100-hPa H₂O > 12 ppmv, despite having only ∼1.8% of all MLS observations. A profile sampled in August 2019 stands out, with H2O=26.3  ppmv, far exceeding the prior record and the median ∼4.5-ppmv abundance in NA. This particular outlier is associated with a large overshooting convective event (OCE) that spanned multiple U.S. states and persisted for several hours. Colocation of the MLS data over NA with cloud observations from Aqua's Moderate Resolution Imaging Spectroradio

SUBMITTER: Werner F 

PROVIDER: S-EPMC7816234 | biostudies-literature | 2020 Dec

REPOSITORIES: biostudies-literature