24 May 2018

Atmospheric River Tracking Method Intercomparison Project (ARTMIP): Project Goals and Experimental Design


ARTMIP (Atmospheric River Tracking Method Intercomparison Project) is a community effort with the explicit goal of understanding the uncertainties, and the implications of those uncertainties, in atmospheric river science solely due to detection algorithm. ARTMIP strives to quantify these differences and provide guidance on appropriate algorithmic choices for the science question posed. Project goals, experimental design, and preliminary results are provided.


The ARTMIP project has been positively received by the AR community and has the potential to shape much how AR science and detection is conducted. This paper describes the experimental design and invites further participation. The project has steadily increased participation since the paper was first presented in the open-forum GMD-Discussions. Preliminary results suggest that the diversity in algorithms does significantly impact how the community describes intensity, frequency, duration, and precipitation attribution. There is potentially more agreement in metrics for the latitude of landfall.


The Atmospheric River Tracking Method Intercomparison Project (ARTMIP) is an international collaborative effort to understand and quantify the uncertainties in atmospheric river (AR) science based on detection algorithm alone. ARTMIP strives to provide the community with information on different methodologies and provide guidance on the most appropriate algorithm for a given science question or region of interest.  All ARTMIP participants will implement their detection algorithms on a specified common dataset for a defined period of time. The project is divided into two phases: Tier 1 will utilize the MERRA-2 reanalysis from January 1980 to June of 2017 and will be used as a baseline for all subsequent comparisons. Participation in Tier 1 is required.  Tier 2 will be optional and include sensitivity studies designed around specific science questions, such as reanalysis uncertainty and climate change.  Proposed metrics include AR frequency, duration, intensity, and precipitation attributable to ARs. This paper presents the ARTMIP experimental design, timeline, project requirements, and a brief description of the variety of methodologies in the current literature. We also present results from our 1-month “proof of concept” trial run designed to illustrate the utility and feasibility of the ARTMIP project.

Christine Shields
National Center for Atmospheric Research (NCAR)
Shields, C, J Rutz, L Leung, F Ralph, M Wehner, B Kawzenuk, J Lora, E McClenny, T Osborne, A Payne, P Ullrich, A Gershunov, N Goldenson, B Guan, Y Qian, A Ramos, C Sarangi, S Sellars, I Gorodetskaya, K Kashinath, V Kurlin, K Mahoney, G Muszynski, R Pierce, A Subramanian, R Tome, D Waliser, D Walton, G Wick, A Wilson, D Lavers, A Collow, H Krishnan, G Magnusdottir, and P Nguyen.  2018.  "Atmospheric River Tracking Method Intercomparison Project (ARTMIP): Project Goals and Experimental Design."  Geoscientific Model Development Discussions 1-55, doi:10.5194/gmd-2017-295.