Modeling, Analysis, Predictions and Projections (MAPP)

The Madden-Julian Oscillation (MJO) is an eastward moving disturbance of clouds, rainfall, winds, and pressure located in the tropical longitudes, which can drive atmospheric circulation around the planet. On average, this atmospheric disturbance travels across the tropics and returns to its initial starting point every 30 to 60 days.

During the winter of 2014 and 2015, the US west coast (USWC) experienced record high temperatures extending from Baja California to the Gulf of Alaska. This record warming, as high as 3°C in some areas, greatly impacted the California Current System (CCS) and Gulf of Alaska marine ecosystems. However, tropical Pacific sea surface temperature anomalies were weak during 2014, calling into question their role in the USWC warming period.

Simulating precipitation is difficult due to the complexity and range of responsible atmospheric processes and technological limitations. In a new Journal of the Atmospheric Sciences paper, author Fiaz Ahmed, and MAPP-funded PI David Neelin used a two-dimensional stochastic model to reproduce observed precipitation cluster distributions, including the slope and cutoff of precipitation events.

As coastal and inundation flooding cause billions of dollars in damage in the United States annually, it’s important to understand the patterns associated with flooding to make a more prepared nation.