Tropical Cyclones and Climate Change: An Indian Ocean Perspective

Abstract This analysis examines the predictability of several key forecasting parameters using the ECMWF Variable Ensemble Prediction System (VarEPS) for tropical cyclones (TCs) in the North Indian Ocean (NIO) including tropical cyclone genesis, pregenesis and postgenesis track and intensity projections, and regional outlooks of tropical cyclone activity for the Arabian Sea and the Bay of Bengal. Based on the evaluation period from 2007 to 2010, the VarEPS TC genesis forecasts demonstrate low false-alarm rates and moderate to high probabilities of detection for lead times of 1–7 days. In addition, VarEPS pregenesis track forecasts on average perform better than VarEPS postgenesis forecasts through 120 h and feature a total track error growth of 41 n mi day−1. VarEPS provides superior postgenesis track forecasts for lead times greater than 12 h compared to other models, including the Met Office global model (UKMET), the Navy Operational Global Atmospheric Prediction System (NOGAPS), and the Global Forecasting System (GFS), and slightly lower track errors than the Joint Typhoon Warning Center. This paper concludes with a discussion of how VarEPS can provide much of this extended predictability within a probabilistic framework for the region.

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Potential of increasing intensity of tropical cyclones due to sea surface temperature and impact on coral reefs in the context of climate change

Disaster Advances ◽

10.25303/149da0107 ◽

2021 ◽

Vol 14 (9) ◽

pp. 1-7

Author(s):

N.D. Hung ◽

L.T.H. Thuy ◽

T.V. Hang ◽

T.N. Luan

Keyword(s):

Climate Change ◽

Coral Reefs ◽

Surface Temperature ◽

Sea Surface Temperature ◽

Tropical Cyclones ◽

Coral Cover ◽

Central Zone ◽

Biosphere Reserve ◽

Sea Surface ◽

Strong Winds

The coral reef ecosystem in Cu Lao Cham, Vietnam is part of the central zone of the Cu Lao Cham -Hoi An, a biosphere reserve and it is strictly protected. However, the impacts of natural disasters - tropical cyclones (TCs) go beyond human protection. The characteristic feature of TCs is strong winds and the consequences of strong winds are high waves. High waves caused by strong TCs (i.e. level 13 or more) cause decline in coral cover in the seas around Cu Lao Cham. Based on the relationship between sea surface temperature (SST) and the maximum potential intensity (MPI) of TCs, this research determines the number of strong TCs in Cu Lao Cham in the future. Using results from a regional climate change model, the risk is that the number of strong TCs in the period 2021-2060 under the RCP4.5 scenario, will be 3.7 times greater than in the period 1980-2019 and under the RCP 8.5 scenario it will be 5.2 times greater than in the period 1980-2019. We conclude that increases in SST in the context of climate change risks will increase the number and intensity of TCs and so the risk of their mechanical impact on coral reefs will be higher leading to degradation of this internationally important site.

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Climate Change, Humanitarian Risks, and Social-Political (In)stability Along the Gulf of Aden: Expert Elicitation for the Case of Somalia and Yemen

10.5194/egusphere-egu21-7575 ◽

2021 ◽

Author(s):

Laurent Lambert ◽

Mahmood Almehdhar ◽

Mustafa Haji

Keyword(s):

Climate Change ◽

Tropical Cyclones ◽

Political Stability ◽

Coastal Areas ◽

Expert Elicitation ◽

Coastal Communities ◽

Gulf Of Aden ◽

The World ◽

Environmental Events

Abstract: Changes in the global oceanic system have already negatively affected the world&#8217;s marine life and the livelihoods of many coastal communities across the world, including in the Middle East' and Eastern Africa's Least Developed Countries (LDCs). Coastal communities in Somalia and Yemen for instance, have been particularly affected by extreme environmental events (EEEs), with an increase in the frequency of tropical cyclones over the past 20 years. Using expert elicitation as a method to generate data to assess and quantify a specific issue in the absence of sufficient and/or reliable data, the authors interviewed selected specialists in or from Somalia and Yemen, from diverse fields of expertise related to climate change, extreme environmental events, disaster risk reduction, and humanitarian affairs. Ten experts followed the elicitation protocol and answered a specific series of questions in order to better quantify the expectable mid-to-long-term climatic and humanitarian levels of risks, impacts, and consequences that climate change and related issues (e.g., sea-level rise, tropical cyclones, and sea surge) may generate in coastal areas along the Gulf of Aden's coastal cities of Aden and Bossaso, in Yemen and Somalia, respectively.The findings indicate that there is cause for significant concern as climate change is assessed by all interviewees - irrespective of their background -, as very likely to hold a negative to a devastating impact on (fresh) water security, food security, public health, social conflicts, population displacement, and eventually political stability; and to strongly worsen the humanitarian situations in Somalia and Yemen, both in the medium-term (i.e., 2020-2050) and the long-term (i.e., 2020-2100). The authors call on the scientific community to further research the issue of climate change in the understudied coastal areas of the Gulf of Aden, and on the international community to pro-actively and urgently help the local populations and relevant authorities to rapidly and strongly build up their adaptation capacities, especially in the niche of coastal EEEs.

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