Backward trajectory analysis of southern California atmospheric rivers
- 7 October 2021
- journal article
- research article
- Published by Inter-Research Science Center in Climate Research
- Vol. 84, 197-214
- https://doi.org/10.3354/cr01657
Abstract
Atmospheric rivers (ARs) are filamentary channels of high water vapor flux that transfer moisture horizontally through the atmosphere at low levels. ARs are often responsible for large annual rainfall totals as well as high-intensity storms due to orographic forcing. ARs are important features when predicting hazardous events such as flooding and are vital components of many regional water budgets. This is especially true for drought-prone areas such as southern California (SCA), which experiences relatively few storms per season, many from AR events. Here, we use a Lagrangian model to create backward air parcel trajectories of 159 AR events that made landfall on the US west coast from December 2004 to December 2015. Trajectories are used to examine the lifecycles and movements of these ARs and to differentiate ARs that made landfall in different regions. Prior to landfall, SCA ARs share similarities to but also have distinct differences from other ARs. At 1000 m above mean sea level (MSL), SCA AR trajectories travel shorter distances over the same 72 h time frame than trajectories for ARs that made landfall farther north. Additionally, along-trajectory measurements for SCA ARs tend to be warmer and have higher specific humidity values. This applies to both the 1000 and 2000 m MSL levels. These results imply that SCA ARs move slower and have the potential to produce higher intensity storms at landfall. An analysis of a case study event of an extreme AR that made landfall in SCA on 17 February 2017 confirms these results.Keywords
This publication has 39 references indexed in Scilit:
- Historical and National Perspectives on Extreme West Coast Precipitation Associated with Atmospheric Rivers during December 2010Bulletin of the American Meteorological Society, 2012
- Winter floods in Britain are connected to atmospheric riversGeophysical Research Letters, 2011
- Climate Change, Atmospheric Rivers, and Floods in California - A Multimodel Analysis of Storm Frequency and Magnitude Changes1Jawra Journal of the American Water Resources Association, 2011
- A Multiscale Observational Case Study of a Pacific Atmospheric River Exhibiting Tropical–Extratropical Connections and a Mesoscale Frontal WaveMonthly Weather Review, 2011
- Atmospheric Rivers, Floods and the Water Resources of CaliforniaWater, 2011
- The NCEP Climate Forecast System ReanalysisBulletin of the American Meteorological Society, 2010
- A Lagrangian Climatology of Tropical Moisture Exports to the Northern Hemispheric ExtratropicsJournal of Climate, 2010
- Meteorological Characteristics and Overland Precipitation Impacts of Atmospheric Rivers Affecting the West Coast of North America Based on Eight Years of SSM/I Satellite ObservationsJournal of Hydrometeorology, 2008
- A Pacific Moisture Conveyor Belt and Its Relationship to a Significant Precipitation Event in the Semiarid Southwestern United StatesWeather and Forecasting, 2007
- Madden‐Julian OscillationReviews of Geophysics, 2005