8th Prediction Science Seminar
(2nd Prediction Science Laboratory and DA Team Joint Seminar)
- Date
- May 11th, 2022(Thu.)17:30-18:15 (JST)
- Language
- English
- Place
-
Zoom or R107
To join the seminar, please contact the Prediction Science Seminar Office: prediction-seminar[remove here]@ml.riken.jp
Program
Time | Content | Speaker |
---|---|---|
17:30-18:00 | Towards acceleration of a high-resolution weather model with machine learning: a summary of short-IPA internship | Ms. Audrey Gonzalo (RIKEN) |
18:00-18:15 | Discussion | - |
Abstract
Towards acceleration of a high-resolution weather model with machine learning: a summary of short-IPA internshipMs. Audrey Gonzalo (RIKEN)
The presenting author Audrey Gonzalo joined the Data Assimilation Research Team in the
course of her French Master 1 degree at IMT-Atlantique, Brest, France, for 6 months under the
RIKEN International Program Associates (IPA). This presentation provides a summary of the short-
term IPA internship on the acceleration of Numerical Weather Prediction (NWP) models with
Machine Learning (ML).
NWP is based on a complex knowledge-based model to compute the high-resolution (HR)
states of the atmosphere. However, the extensive computational cost for real-time prediction using
the NWP model makes it paramount to both alleviate and accelerate the computation. In this regard,
recent studies have shown the interest of ML, more specifically, Neural Networks (NN), to emulate
non-linear processes at a lower computational cost.
We propose to achieve model acceleration by degrading the NWP model resolution and to
downscale the low-resolution (LR) outputs, resorting to a Convolution Neural Network (CNN). This
method is commonly called Super-Resolution (SR) and finds a wide range of applications in various
fields, but most recently geosciences. However, most of the methods are designed for RGB static
images to address issues close to image decompression. In the case of NWP models, the data
comprises underlying dynamics of physical processes, and the approximation of the LR-to-HR
mapping function is fundamentally different from a deblurring task. In fact, our data encompasses
multi-scale phenomena evolving at various scales. Due to the chaotic nature of the atmosphere, the
HR features start diverging in different scales depending on phenomena, making the use of LR alone
insufficient. Considering these specific features, we aim to adopt a cross-disciplinary approach
bridging physics to these cutting-edge SR methods, by building a hybrid method merging both
process-driven approaches of NWP and data-driven approaches of ML.
In this study, we explore accelerating a HR NWP model known as the SCALE model, by
applying a ML-based SR method to map the LR to the HR SCALE outputs. As a first step, we
narrow the problem to only the precipitation variable at the 5000-m level from idealized SCALE
simulations. CNNs require uncorrelated examples to train efficiently, so that we only select training
data with independent HR small-scale features, since the main challenge of SR is to map accurately
these fine-scale residuals. The model’s architecture embedding two input branches was designed
using this key concept of scale-separation.
Overall, our model shows a major improvement compared to the traditional bicubic
interpolation. Further analysis like real-topography experiments may also raise discussions on its
potential future integration within a real prediction system.
Organizer
- Prediction Science Laboratory (RIKEN CPR)
Co-organizer
- Data Assimilation Research Team (R-CCS)
- RIKEN Interdisciplinary Theoretical and Mathematical Sciences Program
- Environmental Metabolic Analysis Research Team (RIKEN CSRS)
- Computational Climate Science Research Team (R-CCS)
- Medical Data Deep Learning Team (R-IH)
- Medical Data Mathematical Reasoning Team (R-IH)
- Laboratory for Physical Biology (RIKEN BDR)