Work Package 3 (WP3)

Estimation of meteorological and marine extremes accounting for climate change.

Research Teams:  HYDRO_AUTh, GEO_AUTh
Work Tasks:     3
Duration: 01/01/2013 – 30/06/2015 (30 months)
Person Months: 36
Deliverables:   3
Analyses of extreme values of meteorological and marine variables in selected regions of the Greek seas (Thracian Sea, Eastern Aegean, Western Aegean, Northern Crete).
Meteorological extremes will be processed using parametric and non-parametric techniques.
Marine extremes will be studied utilizing extreme value techniques, under stationary and non-stationary conditions, considering uncertainty in return level estimates.
Extremes of the combined system of storm surges and their initiating mechanisms (atmospheric pressure, wind velocity) will also be studied.
WT 3.1 - GEO_AUTh:
Initially, extreme meteorological parameters will be analysed. The analysis of the extreme temperature and wind values will be achieved by utilizing both parametric and non-parametric techniques and the characteristics of the deep depressions (intense cyclonic conditions) over the Aegean Sea will be analysed.
WT 3.2 - HYDRO_AUTh:
Waves and storm surges will be considered and their extreme values will be selected and processed. Univariate extreme value techniques, such as the Poisson point process (Coles & Casson 1999) will be used to simulate wave height and storm surge extreme values for the time periods 1961-2000 and 2000-2100, in the abovementioned selected regions of the Greek Seas.
    To incorporate the long-term trends in the wave height and storm surge extreme data, the parameters of the extreme value models considered will be simulated as parametric functions of time.
The effect of climate change on estimating wave height and storm surge prediction uncertainty will also be taken into account. More specifically, the epistemic uncertainties (epistemic uncertainty comprises of the model and the statistical uncertainty, which in turn is subdivided in parameter uncertainty and distribution type uncertainty) in return level estimates will be calculated for both stationary and non-stationary marine variables (waves and storm surges).
Statistical uncertainty will be quantified in the present research by means of the 95% confidence intervals of the return level estimates for both stationary and non-stationary marine variables.
WT 3.3 - HYDRO_AUTh:
The processing of extreme meteorological (air temperature, wind speed and deep cyclonic conditions) and marine (wave height and storm surge) variables will be complemented with analyzing the combined system of the atmosphere and the sea. The dependence in the extreme values of the process of storm surges on their initiating mechanisms (wind speed and atmospheric pressure), based on the circulation types which were studied in WP2 (WT 2.4), will be investigated.

Deliverables

3.1. Technical Report- GEO_AUTh.
DUE DATE: 31/12/2013
Estimation and analysis of the extreme winds, temperature and deep cyclonic conditions (deep depressions) for present and future time periods. (WT 3.1)
3.2. Technical Report-HYDRO_AUTh.
DUE DATE: 30/06/2014
 Estimation of extreme wave height and storm surge events, considering the effects of climate change. (WT 3.2)
3.3. Technical Report-HYDRO_AUTh.
DUE DATE: 30/06/2015
Joint probability analysis of extreme storm surges and their atmospheric initiating mechanisms. (WT 3.3)