Suchergebnisse

Explores the implementation of NATO's Prague, Norfolk, and Munich transformation agendas of adapting to lessons learned from Kosovo, 9/11, Afghanistan, and Iraq. While questions remain as to NATO's unity and "political will," it has successfully expanded membership and improved capabilities and will continue to fulfill its role.

Abstract. Coastal flooding is a major global hazard, yet few
studies have examined the spatial and temporal characteristics of extreme
sea level and associated coastal flooding. Here we analyse sea-level records
around the coast of New Zealand (NZ) to quantify extreme storm-tide and
skew-surge frequency and magnitude. We identify the relative magnitude of
sea-level components contributing to 85 extreme sea level and 135 extreme
skew-surge events recorded in NZ since 1900. We then examine the spatial and
temporal clustering of these extreme storm-tide and skew-surge events and
identify typical storm tracks and weather types associated with the spatial
clusters of extreme events. We find that most extreme storm tides were
driven by moderate skew surges combined with high perigean spring tides. The
spring–neap tidal cycle, coupled with a moderate surge climatology,
prevents successive extreme storm-tide events from happening within 4–10 d of each other, and generally there are at least 10 d between extreme
storm-tide events. This is similar to findings from the UK (Haigh et al.,
2016), despite NZ having smaller tides. Extreme events more commonly
impacted the east coast of the North Island of NZ during blocking weather
types, and the South Island and west coast of the North Island during trough
weather types. The seasonal distribution of both extreme storm-tide and
skew-surge events closely follows the seasonal pattern of mean sea-level
anomaly (MSLA) – MSLA was positive in 92 % of all extreme storm-tide events and
in 88 % of all extreme skew-surge events. The strong influence of
low-amplitude (−0.06 to 0.28 m) MSLA on the timing of extreme events shows
that mean sea-level rise (SLR) of similarly small height will drive rapid
increases in the frequency of presently rare extreme sea levels. These
findings have important implications for flood management, emergency
response and the insurance sector, because impacts and losses may be
correlated in space and time.