1,511 research outputs found
Geodatabase-assisted storm surge modeling
Tropical cyclone-generated storm surge frequently causes catastrophic damage in communities along the Gulf of Mexico. The prediction of landfalling or hypothetical storm surge magnitudes in U.S. Gulf Coast regions remains problematic, in part, because of the dearth of historic event parameter data, including accurate records of storm surge magnitude (elevation) at locations along the coast from hurricanes. While detailed historical records exist that describe hurricane tracks, these data have rarely been correlated with the resulting storm surge, limiting our ability to make statistical inferences, which are needed to fully understand the vulnerability of the U.S. Gulf Coast to hurricane-induced storm surge hazards. This dissertation addresses the need for reliable statistical storm surge estimation by proposing a probabilistic geodatabase-assisted methodology to generate a storm surge surface based on hurricane location and intensity parameters on a single desktop computer. The proposed methodology draws from a statistically representative synthetic tropical cyclone dataset to estimate hurricane track patterns and storm surge elevations. The proposed methodology integrates four modules: tropical cyclone genesis, track propagation, storm surge estimation, and a geodatabase. Implementation of the developed methodology will provide a means to study and improve long-term tropical cyclone activity patterns and predictions. Specific contributions are made to the current state of the art through each of the four modules. In the genesis module, improved representative data from historical genesis populations are achieved through implementation of a stratified-Monte-Carlo sampling method to simulate genesis locations for the North Atlantic Basin, avoiding potential non-representative clustering of sampled genesis locations. In the track module, the improved synthetic genesis locations are used as the starting point for a track location and intensity methodology that incorporates storm strength parameters into the synthetic tracks and improves the positional quality of synthetic tracks. In the surge module, high-resolution, computationally intensive storm surge model results are probabilistically integrated in a computationally fast-running platform. In the geodatabase module, historic and synthetic tropical cyclone genesis, track, and surge elevation data are combined for efficient storage and retrieval of storm surge data
Hurricane Forecasting: A Novel Multimodal Machine Learning Framework
This paper describes a machine learning (ML) framework for tropical cyclone
intensity and track forecasting, combining multiple distinct ML techniques and
utilizing diverse data sources. Our framework, which we refer to as Hurricast
(HURR), is built upon the combination of distinct data processing techniques
using gradient-boosted trees and novel encoder-decoder architectures, including
CNN, GRU and Transformers components. We propose a deep-feature extractor
methodology to mix spatial-temporal data with statistical data efficiently. Our
multimodal framework unleashes the potential of making forecasts based on a
wide range of data sources, including historical storm data, and visual data
such as reanalysis atmospheric images. We evaluate our models with current
operational forecasts in North Atlantic and Eastern Pacific basins on 2016-2019
for 24-hour lead time, and show our models consistently outperform
statistical-dynamical models and compete with the best dynamical models, while
computing forecasts in seconds. Furthermore, the inclusion of Hurricast into an
operational forecast consensus model leads to a significant improvement of 5% -
15% over NHC's official forecast, thus highlighting the complementary
properties with existing approaches. In summary, our work demonstrates that
combining different data sources and distinct machine learning methodologies
can lead to superior tropical cyclone forecasting. We hope that this work opens
the door for further use of machine learning in meteorological forecasting.Comment: Under revision by the AMS' Weather and Forecasting journa
New hurricane impact level ranking system using artificial neural networks, A
2015 Spring.Includes bibliographical references.Tropical cyclones are intense storm systems that form over warm water but have the potential to bring multiple related hazards ashore. While significant advancements have been made for forecasting of such extreme weather, the estimation for the resulting damage and impact to society is significantly complex and requires substantial improvements. This is primarily due to the intricate interaction of multiple variables contributing to the socio-economic damage on multiple scales. Subsequently, this makes communicating the risk, location vulnerability, and the resulting impact of such an event inherently difficult. To date, the Saffir-Simpson Scale, based off of wind speed, is the main ranking system used in the United States to describe an oncoming tropical cyclone event. There are models currently in use to predict loss by using more parameters than just wind speed. However, they are not actively used as a means to concisely categorize these events. This is likely due to the scrutiny the model would be placed under for possibly outputting an incorrect damage total. These models use parameters such as; wind speed, wind driven rain, and building stock to determine losses. The relationships between meteorological and locational parameters (population, infrastructure, and geography) are well recognized, which is why many models attempt to account for so many variables. With the help of machine learning, in the form of artificial neural networks, these intuitive connections could be recreated. Neural networks form patterns for nonlinear problems much as the human brain would, based off of historical data. By using 66 historical hurricane events, this research will attempt to establish these connections through machine learning. In order to link these variables to a concise output, the proposed Impact Level Ranking System will be introduced. This categorization system will use levels, or thresholds, of economic damage to group historical events in order to provide a comparative level for a new tropical cyclone event within the United States. Discussed herein, are the effects of multiple parameters contributing to the impact of hurricane events, the use and application of artificial neural networks, the development of six possible neural network models for hurricane impact prediction, the importance of each parameter to the neural network process, the determination of the type of neural network problem, and finally the proposed Impact Level Ranking System Model and its potential applications
Pangu-Weather: A 3D High-Resolution Model for Fast and Accurate Global Weather Forecast
In this paper, we present Pangu-Weather, a deep learning based system for
fast and accurate global weather forecast. For this purpose, we establish a
data-driven environment by downloading years of hourly global weather data
from the 5th generation of ECMWF reanalysis (ERA5) data and train a few deep
neural networks with about million parameters in total. The spatial
resolution of forecast is , comparable to the ECMWF
Integrated Forecast Systems (IFS). More importantly, for the first time, an
AI-based method outperforms state-of-the-art numerical weather prediction (NWP)
methods in terms of accuracy (latitude-weighted RMSE and ACC) of all factors
(e.g., geopotential, specific humidity, wind speed, temperature, etc.) and in
all time ranges (from one hour to one week). There are two key strategies to
improve the prediction accuracy: (i) designing a 3D Earth Specific Transformer
(3DEST) architecture that formulates the height (pressure level) information
into cubic data, and (ii) applying a hierarchical temporal aggregation
algorithm to alleviate cumulative forecast errors. In deterministic forecast,
Pangu-Weather shows great advantages for short to medium-range forecast (i.e.,
forecast time ranges from one hour to one week). Pangu-Weather supports a wide
range of downstream forecast scenarios, including extreme weather forecast
(e.g., tropical cyclone tracking) and large-member ensemble forecast in
real-time. Pangu-Weather not only ends the debate on whether AI-based methods
can surpass conventional NWP methods, but also reveals novel directions for
improving deep learning weather forecast systems.Comment: 19 pages, 13 figures: the first ever AI-based method that outperforms
traditional numerical weather prediction method
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