A New Lens on Atmospheric Rivers

This presentation introduces the ROTated Atmospheric river coordinaTE (ROTATE) system – a storm-centric coordinate system designed specifically for analyzing long, narrow filamentary regions of intense water vapor transport in the lower atmosphere or so-called atmospheric rivers (ARs). It effectively preserves key AR signals in the time mean that may be lost or obscured in simple averaging due to diverse AR orientations and shapes. We used ROTATE to look at crucial characteristics of atmospheric rivers such as how wet the air is, how fast the wind blows, how much water vapor is being transported, and how much rain falls. We found more apparent AR patterns with ROTATE compared to the conventional non-rotated AR centroid-based compositing approach. The new method also helps us see finer details in rain distributions over land versus over the oceans. It is further apparent that the ROTATE system more distinctly delineates the finer details in precipitation distributions for landfalling and oceanic ARs. Overall, the ROTATE system has the potential to serve as a valuable tool for better comparing and understanding the characteristics, processes, and impacts of ARs across different regions. Details about the analysis and challenges associated with the current results will be discussed in this presentation.