Systemwide Events Calendar

Atmospheric Sciences Seminar

November 10, 3:30pm - 5:00pm
Mānoa Campus, Virtual Meeting

The simplicity of precipitation–dialogue between diagnostics and theoretical underpinnings

Professor J. David Neelin
Department of Atmospheric and Oceanic Sciences
University of California, Los Angeles (UCLA)

You are invited to our weekly online Atmospheric Sciences Fall 2021 seminars via Zoom meeting.
When: November 10, 2021 at 3:30PM HST
Meeting admission: 3:15PM HST

Register in advance for this meeting: https://hawaii.zoom.us/meeting/register/tJwlcOmtpz8iGtFAfj1LmB2t-J89CV76hI1s

After registering, you will receive a confirmation email containing information about joining the meeting. Please save this information for future seminars.

As a security precaution, unmuting microphones, starting video, screen share, and using the 'chat' feature will be disabled for those attending the seminar, except for ATMO faculty. If you would like to say something, please use the 'raise hand' feature. The host or a co-host can then enable you to unmute your microphone.

Abstract:
Precipitation processes are notoriously complex, so it is not surprising that weather and climate models exhibit deficiencies in simulation of probability distributions of precipitation and their relationship to the water vapor and temperature environment. However, we rely on these models for projections of how the probabilities of extreme precipitation will change in a warming climate, so it is important to seek mechanistic understanding that can increase confidence in processes and associated diagnostics to improve models. Here we argue that it can be helpful to return to fundamental questions about what yields the characteristic shapes of probability distributions. This can be asked for different measures of precipitation including event accumulations, daily-average intensities and the size of spatial clusters. Many of these precipitation statistics can be captured by conceptually simple models, based on economical assumptions. These provide an understanding of the underlying processes and point, for instance, to the important role of the threshold-like transition from dry to precipitating conditions as a function of the thermodynamic environment. An overview will be provided of the dialogue between insights from the simple models and diagnostics of observations and complex model simulations.