Annual Progress Report
CLEO 2013
Project
1.1 Climate scenarios
Project leader :
Jonas Olsson, SMHI FoUh, jonas.olsson@smhi.se
Thomas Bosshard, SMHI FoUh, thomas.bosshard@smhi.se
General Objective:
A) Characterisation of the two employed climate projection with respect to a larger ensemble
B) Bias correction of multiple variables at 24 MINT stations for further use in the COUP model
C) Adjustment of the deposition rate according to the bias-corrected precipitation
Short description of activities 2013:
A) A large database of bias-corrected projections for Sweden has been collected. The data will be
used to compare the two CLEO projections with respect to a larger ensemble.
B) The DBS method has been developed to allow bias-correcting of other variables than
temperature and precipitation. Suitable statistical distributions have been evaluated. For all
variables but cloud-fraction, a suitable distribution could be found. The improvements have been
implemented in the DBS code and a tailored bias-corrected data set for the MINT stations for
further use in the COUP model has been produced. This dataset includes temperature,
precipitation, relative humidity and wind speed. The bias-correction of cloud-fraction remains and
will be done in early 2014, using a simpler bias-correction which is not dependent on a statistical
distribution.
C) Efforts have been made to collect the user-needs and to discuss the issue of the deposition rate
with all involved partners. It turned out that the issue of the biases in the deposition rate are not
related to biases in the precipitation, since wet and dry deposition should compensate each other,
given that the atmospheric dynamics remain the same. The decision was taken that all partners will
use a simple bias-correction method, the so-called Delta Change approach, i.e. scaling observed
deposition rates by the changes of deposition rates simulated by the MATCH model.
Deliverables 2013:
To Cluster 3: climate projection data tailored for climate change impact modelling,delivery
month 12, status: partly done, cloud fraction still has to be bias-corrected
To Clusters 3 and 4: characterisation of the two climate projections with focus on their
uncertainties and probabilities of exceedance, delivery month 18, status: ongoing
To Cluster 2: quantification of DBS impact on deposition-related precipitation
characteristics , delivery month 18, status: done (decision has been made to use a Delta
Change approach)
Additional staff involved in project:
Wei Yang, SMHI FoUh, wei.yang@smhi.se
Co-operation outside CLEO:
Similar objectives as in CLEO are pursued in the Brandrisk project, and a close
cooperation is therefore fostered, for e.g., regarding the bias-correction of relative
humidity and wind speed.
Reports and publications:
Arheimer, B., Olsson, J., and L. Strömbäck (2013) “Dissemination and end-user
interactions of climate change impact on water resources” Journal of Water Management
and Research (VATTEN), 69: 193-199.
Dahné, J., Donnelly, C., and J. Olsson (2013) “Post-processing of climate projections for
hydrological impact studies, how well is the reference state preserved?” IAHS Publications
359: 53-59.
Olsson, J., W. Yang, and T. Bosshard. (2013), "Climate model precipitation in hydrological
impact studies: limitations and possibilities." Journal of Water Management and Research
(VATTEN) 69: 221-230.
Yang, W., Gardelin, M., Olsson, J., Andréasson, J., Sahlberg, J., Stensen, B. (in prep.),
”Forest fire risk assessment in Sweden using climate model data: bias correction and
future changes”
Oral presentations:
-