Marie-Dominique Leroux

Meteo France La Réunion · Etudes et climatologie

This report was written for the Eigth International Workshop on Tropical Cyclones (IWTC8, Dec 2014). It focuses on new advances (2010-2014) regarding tropical cyclone (TC) intensity change induced by external influences . It briefly recalls the framework and main areas of progress identified during the last IWTC (2010). It then highlights the major...

The rapid intensification of Tropical Cyclone (TC) Dora (2007, southwest Indian Ocean) under upper-level trough forcing is investigated. TC–trough interaction is simulated using a limited-area operational numerical weather prediction model. The interaction between the storm and the trough involves a coupled evolution of vertical wind shear and bina...

The impact of initial structure on storm evolution is examined for the case of a tropical storm entering rapid intensification. At the onset of rapid intensification, satellite cloud signatures suggest that the structural organization of Typhoon Sinlaku (2008) was dominated by a primary band of convection present at outer radii. The development of...

The data of the BRIO project described in https://www.sciencedirect.com/science/article/pii/S2405880724000463

The present article describes a dataset encompassing model outputs generated by the Weather Research and Forecasting (WRF) regional climate model. A high-resolution (1km) downscaling simulation was performed over two tropical islands, Reunion and Mauritius, situated in the South-West Indian Ocean (SWIO), with initial and boundary conditions provide...

The recent expansion of Aedes albopictus across continents in both tropical and temperate regions and the exponential growth of dengue cases over the past 50 years represent a significant risk to human health. Although climate change is not the only factor responsible for the increase and spread of dengue cases worldwide, it might increase the risk...

https://ideas4development.org/changement-climatique-en-marche-ocean-indien/

This research work was motivated by the lack of quality climate data specifically designed for the anticipation of climate change in the Southwest Indian Ocean (SWIO) basin that stretches from 30 to 90 degrees East. This region is prone to tropical cyclone activity with an average of 9.7 tropical systems developing each year, among which 4.8 system...

Tropical Cyclone (TC) Oswald made landfall over northeast Australia as a 17 minimal or Category 1 TC on the Australian scale on 21 January 2013. As it 18 moved southward, it intensified over land and produced extreme rainfall for 19 nearly seven days. Tornadoes were reported and confirmed. Tragically seven 20 people died and insurance estimates wer...

https://ideas4development.org/en/climate-change-in-the-indian-ocean-more-accurate-simulation-models-for-better-adaptation/

https://ideas4development.org/en/climate-change-in-the-indian-ocean-more-accurate-simulation-models-for-better-adaptation/ https://ideas4development.org/ideas4development-org-modeles-climatiques-ocean-indien/

In late March 2014, very intense Tropical Cyclone Hellen threatened the Comoros Archipelago and the Madagascan northwest coastline as it became one of the strongest tropical cyclones (TCs) ever observed over the Mozambique Channel. Its steep intensity changes were not well anticipated by operational forecasting models or by La Reunion regional spec...

Under the responsibility of the Regional Specialized Meteorological Centre (RSMC) of La Réunion, the southwest Indian Ocean (SWIO) has tropical cyclone activity close to that of the North Atlantic. Like most territories of the SWIO basin, La Réunion island is highly vulnerable to cyclone‐induced hazards and the potential impact of nearby storms is...

Like Taiwan, the orography of Reunion Island may impact tropical cyclone (TC) track and intensity. A Mann–Whitney test is applied on best‐track data from the Regional Specialized Meteorological Center (RSMC) La Reunion to demonstrate that this effect is detectable at less than 250 km from the island. A set of idealized experiments is carried out to...

Tropical cyclone (TC) Oswald made landfall over north-east Australia as a minimal or Category 1 TC on the Australian scale on 21 January 2013. As it moved southward, it intensified over land and produced extreme rainfall for nearly 7 days. Tornadoes were reported and confirmed. Tragically, seven people died and insurance estimates were ~$1 billion....

This review prepared for the fourth International Workshop on Tropical Cyclone Landfall Processes (IWTCLP-4) summarizes the most recent (2015-2017) theoretical and practical knowledge in the field of tropical cyclone (TC) track, intensity, and structure rapid changes at or near landfall. Although the focus of IWTCLP-IV was on landfall, this summary...

This report briefly summarizes recent progress in storm surge forecasts, one of topics discussed during the fourth International Workshop on Tropical Cyclone Landfall Process (IWTCLP 4) held during 5-8 December, 2017. In the workshop, improvement of storm surge forecasting system was mainly discussed with relevance to the problem of estimating the...

The Fourth International Workshop on Tropical Cyclone Landfall Processes (IWTCLP-4) was held in Macao, China from 5-7 December 2017. The workshop was organized by the World Meteorological Organization (WMO) Expert Team on Tropical Cyclone Landfall Processes in partnership with the WMO Tropical Cyclone Program. The workshop provided a forum for disc...

A 17-yr "climatology" of tropical-system activity, track, size, and 24-h intensity change in the southwest Indian Ocean (SWIO) is developed and analyzed in comparison with other intensively studied basins such as the North Atlantic Ocean.Afirst formulation of the empirical maximumpotential intensity of SWIO tropical systems is also proposed, along...

This review prepared for the fourth International Workshop on Tropical Cyclones Landfall Processes (IWTCLP-4, Macau, China) summarizes the most recent (2015-2017) theoretical and practical knowledge in the field of tropical cyclone (TC) track, intensity, and structure rapid changes at or near landfall.

A 15-year (1999-2014) homogeneous database from RSMC La Reunion is employed to examine the large-scale characteristics of rapidly intensifying tropical cyclones over the southwest Indian Ocean. To allow for basin inter-comparisons we followed the methodology used by Kaplan and DeMaria (2003; 2010) for Atlantic systems. Rapid intensification (RI) fo...

This study is part of the efforts undertaken to resolve the “bad trough/good trough” issue for tropical cyclone (TC) intensity changes and to improve the prediction of these challenging events. Sensitivity experiments are run at 8-km resolution with vortex bogusing to extend the previous analysis of a real case of TC–trough interaction (Dora in 200...

This report presented at the Eigth International Workshop on Tropical Cyclones (IWTC8, Dec 2014) focuses on new advances (2010-2014) regarding tropical cyclone (TC) intensity change induced by external influences . It briefly recalls the framework and main areas of progress identified during the last IWTC (2010). It then highlights the major operat...

A previous study on TC Dora (2007) in the southwest Indian Ocean gave some insight on the pathway to storm intensification under upper-level trough forcing. The French operational hydrostatic limited-area model at 8-km resolution, Aladin-Reunion, allowed diagnoses of trough impacts in the TC core. The main mechanisms identified for vortex intensifi...

We re-visit the Tropical Cyclone, TC-trough interaction problem and provide evidence that some types of amplifying Rossby Waves provide favourable settings for interaction and injection of environmental air with high potential vorticity (PV) into TC circulations through midlevels. Ex-TC Oswald produced extreme rainfall over northeast Australia. We...

Despite significant improvements in Tropical Cyclone (TC) track forecasts over the past few decades, anticipating the sudden intensity changes of TCs remains a major operational issue. The main purpose of this thesis is to analyze TC rapid intensification processes in relation with external forcing induced by upper-level troughs originating from th...

Dans un contexte international, la prévision d'intensité des cyclones tropicaux connaît encore de graves déficiences tandis que la prévision de trajectoire de ces phénomènes météorologiques extrêmes s'est grandement améliorée ces dernières décennies. Une source d'erreur pour la prévision d'intensité est le manque de connaissance des processus physi...

An example of a favourable interaction between a tropical cyclone (TC) and an upper-level trough is examined from a numerical modelling perspective. In relation with a Rossby wave breaking event taking place in the southwest Indian Ocean, an upper-level potential vorticity (PV) anomaly, associated with a midlatitude trough, approached TC Dora (2007...

We investigate the motion and rapid intensification of Typhoon Sinlaku, which occurred during the 2008 Tropical Cyclone Structure Experiment (TCS08) over the Northwest Pacific. For the period 9 to 12 September 2008, Sinlaku underwent large motion and internal structure changes, including the development of multiple eyewalls and possibly multiple wi...