Multiscale Nature of Atmospheric Rivers

Abstract

Society (AMS) defined AR as "a long, narrow and transient corridor of strong horizontal water vapor transport typically associated with a low-level jet stream ahead of the cold front of an extratropical cyclone" (Ralph et al., 2018).However, as implied in the AMS definition, not all ARs are related to extratropical cyclones. Zhang et al. ( 2019) reported that about 15%-20% of cool-season ARs in the eastern North Pacific are not concurrent with extratropical cyclones nearby. Likewise, not all extratropical cyclones are paired with ARs in the North Pacific and the North Atlantic (Eiras-Barca et al., 2018;Guo et al., 2020). By applying the AR concept, the conduits of intense water vapor transport have been studied worldwide including those in the Mediterranean

Atmospheric River Rapids and Their Role in the Extreme Rainfall Event of April 2023 in the Middle East

“…Satellite-derived precipitation estimates from the Integrated Multi-Satellite Retrievals for the Global Precipitation Measurement (GPM) mission (IMERG; Huffman et al, 2020;Pradhan et al, 2022), available every 30-min at 0.1°(∼11.1 km) resolution, and ground-based observations from weather stations that comprise the National Oceanic and Atmospheric Administration's Global Surface Summary of the Day (Lackey, 2020b) catalog, are used to assess the precipitation generated by the AR. In-situ hourly meteorological observations (Herzmann, 2024) and up to twice daily sounding profiles (Oolman, 2024) at airport stations are considered to inspect the local effects of the ARs. The moisture sources that contributed to the AR are identified through backtrajectories obtained with the Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT; Stein et al, 2015) model driven by ERA-5 data.…”

“…ERA-5 reanalysis data, available at ∼27 km spatial resolution and hourly temporal resolution, is extracted from the Copernicus Climate Data Store's website (Hersbach et al, 2024a(Hersbach et al, , 2024b. Sounding profiles available at best twice daily are downloaded from the University of Wyoming's website (Oolman, 2024) while ground-based hourly observations at airport stations, Meteorological Aerodrome Reports, are freely available at the Iowa State University Iowa Environmental Mesonet's website (Herzmann, 2024). The National Oceanic and Atmospheric Administration (NOAA) Global Surface Summary of the Day (GSOD) data is downloaded from the NOAA's National Centers for Environmental Information website (Lackey, 2020a).…”

“…They are generally detected based on the associated integrated vapor transport (IVT), which is the column integral of the flux of water vapor carried by the horizontal wind flow (Guan & Waliser, 2015; Guan et al., 2023; Lora et al., 2020; Zhou et al., 2018), while their strength and impacts are typically a function of the magnitude and persistence of high IVT values (Eiras‐Barca et al., 2021; Esfandiari & Rezaei, 2022; Ralph et al., 2019). ARs are associated with different time‐scales, ranging from high‐frequency (<10 days) predominantly over the mid‐latitude storm tracks, to low‐frequency in the summer monsoon regions, with intermediate ARs found on the poleward side of subtropical highs (Park et al., 2023). While in monsoon and lower latitude regions they further exacerbate rainfall events (Liang & Yong, 2021; Park et al., 2021; Vallejo‐Bernal et al., 2023; Yang et al., 2018), at high‐latitudes and over the high‐terrain, ARs can have a substantial effect on sea‐/land‐ice and snow cover (Box et al., 2023; Bozkurt et al., 2021; Fonseca et al., 2023; Francis et al., 2020, 2021a, 2022a, 2022b; Meinander et al., 2023; Shields et al., 2022b; Wille et al., 2024a, 2024b; Zhang et al., 2023).…”