PAC : Pollen Allergie Climat Octobre 2008 – Octobre 2011 LISA

Introduction
Pollen is one of the main allergenic factor
Allergenic disease as been multiplied by 3 in France
during last 25 years
==> large human health problem!
A multiple link with climate change
Change in plant phenology
change in period of pollen
emission
Change in plants productivity
change in pollen
production
Change in plant distribution (+ land use change)
Change in allergenicity of pollen
Change in atmospheric transport.
the PAC project
Modeling the dynamic of allergenic pollen
concentration in the atmosphere
Main goals of the project
Outil
Objectifs
applications
Court terme
Prévision de risque
allergène
Long terme
Impact du changement
climatique
Plateforme de
modélisation des
concentrations de
pollen dans l’air
Task force in the GIS
Écologie
LSCE
LMD
LISA
CEFE
PAC
RNSA
CERVEAU
PIFO
GIS Climat
Santé
Extérieurs au GIS
Appartenant au GIS
Modélisation
A strong multidiciplinarity
project related to theme 3 and 4
Of the GIS
Un good « ecosystem »:
- Vegetation modeling (LSCE)
-chemistry/transport modelling
(LMD/LSCE)
- Medical risk (PIFO)
With an external link thru GDR 2968:
I.Chuine (CEFE): phenology modeling
M.Thibaudon (RNSA): pollen
observation
GDR 2968 « phénologie »
Comparison with state of art
Several attempt to relate pollen concentration to risk or
estimate pollen concentration (ex: Sofiev et al.)
Not a complete chain of the processes
Empirical approaches
We tried a more mechanistical approach representing all the processes from
Pollen production, emission and transport
The modelling plateform
météorology
Flowering model
(Chuine et al.)
Map of risk
Flowering
period
Productivity model
(ORCHIDEE)
Pollen production
Concentration/risk
relationship
Total pollen/plant
Vegetation map
Pollen emission
(Helbig et al.)
Flux/m2
Transport model
CHIMERE
(INCA)
Hourly map of
Pollen
concentration
A first cas study: Birch
+densité
Map of Birch 8km
2nd step:phenological modelling
Phenological Modelling Plateform (PMP)
Chuine et al. 2000
Calibration on RNSA dataset
• 70 stations
• 10 years of bi-hourly measurements
- More than 20 pollens
Calibration
Concentrations
polliniques
(années passées)
Ajustements
PMP
Températures
relevées (années
passées)
Dates de
floraison prévues
Paramètres ajustés
Prévision
PMP
Températures de
l’années (passées
+prévues)
Result: date of pic of pollen
production in 2008
Map of pollen emission pic
Comparison to Lyon station
Comparaison between simulated production and observed concentration
Interannual variability of beginning of emission period
Evolution of pollen production in
2008
26/03
02/04
12/04
16/04
02/05
Transport du pollen
Main processes of pollen transport
Parameterization into CHIMERE
o
o
Transport and settling: Change in dust transport
Change in dimension
Change in density
Resuspension: function of air humidity and wind speed
(Helbig et al. 2004).
Viability of pollen: fct of age and radiation
Un exemple sur un cas idéal
Surface
0-5 °E (~555 km)
44-48°N (~445 km)
Constant emission of
105 grains cm-2
Ex: 2 contrasted meteo
July 2009: very wet
August 2003: drought
Simulated concentration
Surface layer
50 m
pollen concentration 07/30/2003 at 7:00, 14:00,
23:00
Examples of atmospheric profiles
Effect of night deposition
Effect of rainfall
K
Evolution of surface concentration
Heat wave 2003
July 2009
Distance moyenne parcourue: dmoy
= 240 km
Resuspension
Without resuspension
With resuspension
3°E 46°N
0,6°E 48,5°N
In general resuspension increase pollen concentration
Schedule for end of the project
Maps of emissions for last decade
Simulation of transport with chimere
Preliminary Comparison with RNSA data
Perspectives and difficulties.
Extension to others pollens:
o No main difficulties for others trees.
o More complex for herbaceous vegetation:
1/ Annual change of spatial distribution
2/ strong link with land use
Link with medical risk
Follow up of PAC
The European project ATOPICA
Coordination: Vienna medicine university
Objective: Evaluation of atopic disease of Ambrosia with
climate change.