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Principle
Researchers:
Eila Gendig
Marwan Katurji
Collaborators:
Renan Le Roux
Hervé Quénol
VINEYARD SCALE
CLIMATOLOGY
Accuracy of forecasts and downscaling
Brief Outline




Dynamical weather modelling
Accuracy of the dynamic weather model
(WRF: Weather Research and Forecasting
system)
Geo-statistical downscaling for enhanced
spatial resolution
Outlook
Dynamical Weather Modeling


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
Weather Research and Forecasting Model
(WRF)
Hindcasting and forecasting
Hourly data
Range of climatological variables
1 km resolution
W
Soil/Surface type
Topography
Land use
Global atmospheric
Geographical boundary circulation data
INPUT
R
F
OUTPUT
Aim

How good is the forecast?
Observation


Air temperature, wind speed, wind direction,…
Temporal Resolution

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
Model
Seasonality?
Diurnal changes?
Meteorological phenomena
Spatial Relationships


Coastal sites vs. inland sites
Awatere Valley vs. Wairau Valley
Automatic Weather Stations
Validating Air Temperature I

1 growing season (8 months)
 01/09/2013

to 30/04/2014
Daily mean air temperature (°C)
Observation
WRF
Min
Max
Mean
Min
Max
Mean
6.9
23.4
15.0
6.2
20.5
14.4
Bias = WRF –
Observation
= 14.4°C – 15.0°C
= -0.6°C
-5
0
5
Bias (°C) =
∆ Temperature (°C)
Validating Air Temperature II
Sunrise
WRF too warm
Sunset
Wind Speed Bias
Summary and Future Work

Weather model evaluation was done for one
growing season. Mean daily air temperature bias
from 11 weather stations was between -2.2 to 0.5 oC

Further model evaluation is required to relate model
error to season, weather types and hour of the day

The latter will allow for a process based
understanding of the model error. This is essential
for tuning specific components of the weather
modeling system
Geostatistical Downscaling

Increasing spatial resolution

Enabling a closer look at the spatial variability
of air temperature
More accurate determination of growing
degree days (GDDs)

Geostatistical Downscaling
Landscape parameters
Locality
Slope
Aspect
Elevation
Lower
resolution
temperature
Multi-parameter
regressive
model
Landscape
parameters
Higher
resolution
temperature
Geostatistical Downscaling
Air
temperature
50 m grid
resolution
1000 m grid
resolution
Summary and Future Work

Preliminary geo-statistical downscaling provides
ultra-high spatial resolution of air temperature

Geo-statistical downscaling will be carried out for the
entire growing season and evaluated in a similar
way to the dynamical weather model

A combination of dynamical and statistical weather
modeling will be coupled to the weather and GDD
forecasts on wineclimate.co.nz for 2015.