Reconstruction of
regional climate and climate change in
past decades: CoastDat
Hans von Storch, Frauke Feser,
Ralf Weisse and Matthias Zahn
Institute for Coastal Research, GKSS Research Center, Germany
and KlimaCampus, U of Hamburg, Germany
What is coastDat?
A set of model data of recent, ongoing and possible future coastal
climate
(hindcasts 1948-2008, reconstructions and scenarios for the future, e.g., 2070-2100)
Based on experiences and activities in a number of national and
international projects (e.g. WASA, HIPOCAS, STOWASUS, PRUDENCE)
Presently contains atmospheric and oceanographic parameter
(e.g. near-surface winds, pressure, temperature and humidity; upper air meteorological data
such as geopotential height, cloud cover, temperature and humidity; oceanographic data
such as sea states (wave heights, periods, directions, spectra) or water levels (tides and
surges) and depth averaged currents, ocean temperatures)
Covers different geographical regions
(presently mainly the North Sea and parts of the Northeast Atlantic; other areas such as the
Baltic Sea, subarctic regions or E-Asia are to be included)
http://www.coastdat.de, contact: Ralf Weisse (ralf.weisse@gkss.de)
Overview
a) Construction of CoastDat
b) Validation of CoastDat
c) Applications
Downscaling cascade.
run with NCEP, 1948-2008
variance
global model
Insufficiently
resolved
Well resolved
Spatial scales
variance
regional model
Insufficiently
resolved
Well resolved
Spatial scales
Added value
Concept of Dynamical Downscaling
RCM
Physiographic detail
3-d vector of state
State space equation
Ψ t +1 = F(Ψ t ;ηt ) + εt
Observation equation
d t = G(Ψ t ) + δt
Known large scale state
ε t , δ t = model and observation errors
with
F =projection
dynamicalof
model
full state on largescale
G = observatioscale
n model
Ψ t*+1 = F(Ψ t ;ηt )
Forward integration :
d t*+1 = G (Ψt*+1 )
⇒ Ψ t +1 = Ψ t*+1 + K(d t*+1 − d t +1 )
with a suitable operator K .
Large-scale (spectral)
nudging
Extreme wind speeds over sea
– simulated and recorded
simulated
Hourly data, 50 km
grid, 1948-2008
Interannual Variability Water Levels
(Weisse and Plüß 2006)
Annual mean winter high waters Cuxhaven
red – reconstruction, black – observations
Applications
1.
2.
3.
4.
5.
N European Storm Climate and related issues
(incl. industrial applications)
Polar Lows in the North Atlantic
Polar Lows in North Pacific
Typhoons in E Asia
Pathways of gasoline lead pollution
Changing significant wave height, 1958-2002
waves
50,75, 90, 95, 99 and 99.9%iles of
significant wave heights (m) and
linear trends
wind
Some applications of coastDat
- Ship design
- Problem:
. RoRo liners operating on fixed routes
. Operation time critical
- Idea:
. Optimization of velocity profile taking
environmental conditions into account
(e.g. water depth, wave height, wave angle)
- Example:
. 200 m RoRo liner Zeebrügge-Immingham
. Compared to conventional approach delayed
in 7% of time; only in 0.5% more than 30 min
. Reduced operation costs
(200 TEUR/year due to reduced fuel consumption)
Source: Flensburger Schiffbau Gesellschaft
Climate simulations with CLM ( ~50km) for Polar Lows 1948-2007
Zahn, M., and H. von Storch, 2008: A longterm climatology of North Atlantic Polar Lows.
Geophys. Res. Lett., 35, L22702, doi:10.1029/2008GL035769
For scenarios, see poster: Future projections of North Atlantic polar low frequency
North Atlantic Polar Lows
Lead deposition in Europe
Flow
• Many anthropogenic substances
released into the environment
are transported over long
distances and are deposited all
over Europe and the rest of the
world.
• Long term and spatially
representative measurements
unavailable. Alternative: use of
and deposition circulation and precipitation
long-term weather
of substances from
reconstruction to model fate of
substances.
von Storch, H., M. Costa-Cabral, C. Hagner, F. Feser, J. Pacyna, E. Pacyna, and S.Kolb, 2003:
Four decades of gasoline lead emissions and control policies in Europe: A retrospective
assessment, The Science of the Total Environment (STOTEN) 311, 151-176
Lead in Europe, 1975
Emissions
Depositions
model
estimate
Weisse, R., H. von Storch, U.
Callies, A. Chrastansky, F. Feser,
I. Grabemann, H. Günther, A.
Plüss, T. Stoye, J. Tellkamp, J.
Winterfeldt and K. Woth, 2009:
Regional meteo-marine
reanalyses and climate change
projections: Results for Northern
Europe and potentials for
coastal and offshore
applications.
Bull. Amer. Meteor. Soc. 90:
849-860
(open access)