Global Atmospheric River Lifecycle Detection Using Integrated Water Vapor and Vapor Transport

Atmospheric rivers (ARs) are narrow streams of enhanced water vapor transport. While there is no accepted quantitative definition of ARs, integrated water vapor transport (IVT) is most commonly used to detect them. Nevertheless, narrow features of enhanced total precipitable water (TPW) are common signatures of ARs. Current AR tracking methods are generally limited to using either IVT or TPW separately, and many do not track the ARs globally through their life cycles. In this study, a global Atmospheric River Lifecycle Detection (ARLiD) method and 44-year database that incorporates both IVT and TPW are presented. The inclusion of TPW provides consistency in identifying entire lifecycle of ARs and reduces uncertainties due to small changes in wind. ADLiD extends the AR systems both equatorward and poleward of the IVT. The data are useful for studies that wish to include portions of the AR life cycle during which the AR, or portions of the AR, have a stronger signature in TPW than in IVT.