 |
| Titel |
Automated classification of the atmospheric circulation patterns that drive regional wave climates |
| VerfasserIn |
J. Pringle, D. D. Stretch, A. Bárdossy |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1561-8633
|
| Digitales Dokument |
URL |
| Erschienen |
In: Natural Hazards and Earth System Sciences ; 14, no. 8 ; Nr. 14, no. 8 (2014-08-22), S.2145-2155 |
| Datensatznummer |
250118604
|
| Publikation (Nr.) |
 copernicus.org/nhess-14-2145-2014.pdf |
|
|
|
|
|
| Zusammenfassung |
| Wave climates are fundamental drivers of coastal vulnerability;
changing trends in wave heights, periods and directions can severely impact a
coastline. In a diverse storm environment, the changes in these parameters
are difficult to detect and quantify. Since wave climates are linked to
atmospheric circulation patterns, an automated and objective classification
scheme was developed to explore links between synoptic-scale circulation
patterns and wave climate variables, specifically wave heights. The algorithm
uses a set of objective functions based on wave heights to guide the
classification and find atmospheric classes with strong links to wave
behaviour. Spatially distributed fuzzy numbers define the classes and are
used to detect locally high- and low-pressure anomalies. Classes are derived
through a process of simulated annealing. The optimized classification
focuses on extreme wave events. The east coast of South Africa was used as a
case study. The results show that three dominant patterns drive extreme wave
events. The circulation patterns exhibit some seasonality with one pattern
present throughout the year. Some 50–80% of the extreme wave events are
explained by these three patterns. It is evident that strong low-pressure
anomalies east of the country drive a wind towards the KwaZulu-Natal
coastline which results in extreme wave conditions. We conclude that the
methodology can be used to link circulation patterns to wave heights within a
diverse storm environment. The circulation patterns agree with qualitative
observations of wave climate drivers. There are applications to the
assessment of coastal vulnerability and the management of coastlines worldwide. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|