This notebook describes the main functionalities of TAIFU-WW

Functionalities:

1) Hindcast past tropical cyclones: compute time series and wave/wind field of a specific event
2) Derive extreme wind and wave statistics in cyclonic conditions only and in mixed climate conditions

Three databases:

- IBTrACS database: historical database of TC
- Hindcast ERA-5 database
- STORM: Synthetic Tropical cyclOne geneRation Model (Bloemendall et al.,2020)

# Project: OROWSHI
# Copyright (c) 2025 France Energies marines
#
# Private Collaboration License:
# This file is part of a closed collaborative project. Use, modification, or redistribution
# is restricted to officially recognized partners. No external disclosure or distribution
# is allowed without prior written agreement from France Energies Marines.
#
# All modifications and improvements must be shared with all partners under the same terms.
#
# See LICENSE.txt for the complete terms and conditions.
import warnings
warnings.filterwarnings("ignore")
import os
import matplotlib.pyplot as plt
import pandas as pd
import xarray as xr 
import numpy as np
from scipy.stats import *
import sys
sys.path.append("../src/")
import datetime
import API,process_data

Case study: Isumi - INFLUX wind farm (140°35'32"E, 35°17'26"N) - 10 km offshore from Isumi

Hub height wind speed is computed using the OROWSHI model

hub_height = 150 
wind_model = 'LO15' # Wind model from Loridan et al. (2015), fitted on SAR dataset (Vinour et al., 2025)

The input parameters are gathered in the TC_input object

TC_input = process_data.TCInput(mode = 'W&W',
                                lat_pnt = 35.290550,
                                lon_pnt = 140.592266,
                                wind_model = wind_model,
                                height_of_interest = hub_height, 
                                TC_name = "HAGIBIS",
                                year = 2019,
                                specific_date = "10/12/2019 12:00:00")

Wind speed and significant wave height induced by Typhoon Habigis (2019) are computed at the site of interest

TC = API.Compute_time_series(TC_input)

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GM23 computation

100%|████████████████████████████████████████████████████████████████████████████████████| 1/1 [00:02<00:00,  2.94s/it]

Surface wind and wave fields are computed at a specific date (The map may take a few minutes to display)

API.Compute_field(TC_input) 

GM23 computation

100%|████████████████████████████████████████████████████████████████████████████████████| 1/1 [00:00<00:00,  1.58it/s]

	lon	lat	lon_cart (m)	lat_cart (m)	Hs (m)	Tp (s)
0	[139.39999389648438]	[35.599998474121094]	[[1000.0, 3004.016064257028, 5008.032128514056...	[[0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0,...	[[10.364788681878142, 10.467948413490639, 10.5...	[[15.845362686312166, 15.858416520484067, 15.8...

TAIFU-WW enables the computation of joint statistics of wind speed and significant wave height using the STORM synthetic database. The contribution of the swell emitted by distant weather systems is taken into account in the statistics of Hs.

TC_input.dmin = 250 # GM23 can be applied up to 250km from the site
TC_input.database = 'STORM'
TC = API.TC_Stats(TC_input)

Process STORM dataset
1000 years
GM23 computation

100%|██████████████████████████████████████████████████████████████████████████████████| 11/11 [08:58<00:00, 48.99s/it]

Swell contribution is taken into account

TC-only wind speed univariate statistics:
------------
############
50-years return value: 55.54 m/s
500-years return value: 61.85 m/s
############

TC-only Hs univariate statistics:
------------
############
50-years return value: 18.47 m
500-years return value: 21.51 m
############

For sites located at mid-latitudes or in transitional climate zones, the contribution of extratropical cyclones to wind and wave extremes may be significant. TAIFU-WW also allows univariate statistics to be derived in a mixed climate:

RV = API.Combined_stats(TC_input)

Process STORM dataset
1000 years
GM23 computation

100%|██████████████████████████████████████████████████████████████████████████████████| 11/11 [11:05<00:00, 60.53s/it]

Swell contribution is taken into account

TC-only wind speed univariate statistics:
------------
############
50-years return value: 55.54 m/s
500-years return value: 61.85 m/s
############

TC-only Hs univariate statistics:
------------
############
50-years return value: 18.79 m
500-years return value: 21.65 m
############

Mixed Climate wind speed statistics:
------------
############
50-years return value: 55.54 m/s
500-years return value: 61.85 m/s
############

Mixed Climate Hs statistics:
------------
############
50-years return value: 18.36 m
500-years return value: 21.21 m
############