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Explore using inverse modeling to estimate aerosol and precursor sources in Europe. Discuss strengths, challenges, and requirements for efficient modeling. Includes examples and perspectives on methane emissions.
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Inverse modeling of European sources: Perspectives for aerosols and its precursors Maarten Krol, Frank Dentener, Peter Bergamaschi, Jean-Philippe Putaud, Frank Raes JRC, Ispra JRC – Ispra
What is inverse modeling? Example: Estimating European emissions of methane Strengths and weaknesses Perspectives for shorter-lived compounds Requirements Outline JRC – Ispra
Model Parameters (P) Model Emission Estimates (P) What is inverse modeling? Output (C(x,t)) Measurements (M(x,t)) Sensitivity: JRC – Ispra
Sensitivity: Minos 2001 Region of influence 1/8/2001 - 19/8/2001 JRC – Ispra
Optimize model parameters by minimizing the difference between model & measurements Minimize cost function: J = Si (Mi(x,t) – Ci(x,t,P))2/ (sMi(x,t))2 + (parameter term) Note: Ci(x,t) depends on P This links to sensitivities S From Sensitivity to Inverse modeling JRC – Ispra
EXAMPLE: Inverse modelling of national and European CH4 emissions using the zoom model TM5 P. Bergamaschi, M. Krol, F. Dentener, and F. Raes EC Joint Research Center, Ispra, Italy in cooperation with several partners: - Institute for Marine and Atmospheric Research, Utrecht, Netherlands - ECN Petten, Netherlands - Umweltbundesamt, Germany - CEA/CNRS, Gif sur Yvette, France - NOAA Climate Monitoring and Diagnostics Laboratory, Boulder, CO, USA JRC – Ispra
TM5 model TM5 model – atmospheric zoom model • offline atmospheric transport model • meteo from ECMWF • global simulation 6o x 4o • zooming 1o x 1o (Europe, …) • http://www.phys.uu.nl/~tm5/ JRC – Ispra
Global and European regions JRC – Ispra
Global and European regions JRC – Ispra
monitoring sites JRC – Ispra
Schauinsland JRC – Ispra
further European sites complete set of 56 sites (year 2001) ftp://ftp.ei.jrc.it/pub/bergamas/CH4BR/ JRC – Ispra
CH4 emission distribution - bottom up JRC – Ispra
CH4 emission distribution - a posteriori JRC – Ispra
a priori / a posteriori emissions JRC – Ispra
revision of German inventory revision of German inventory (EU NIR 2004) 2.40 -> 4.04 Tg CH4/yr (year 2001); revision of whole time series manure management (0.21 -> 1.31 Tg CH4/yr), mainly due to increased CH4 conversion factors from liquid manure management systems Furthermore: frequency distribution of manure management systems by district instead of fixed emission factors for each animal type; incorporation of smaller Bundeslaender, which in previous reports had not been included JRC – Ispra
a priori / a posteriori emissions JRC – Ispra
Forward simulation for Pallas (2002) a priori emission inventory (3 Tg CH4/ yr from Finnish wetlands) yields much too high CH4 mixing ratios during summer JRC – Ispra
Workshop"Inverse modelling for potential verification of national and EU bottom-up GHG inventories " under the mandate of Monitoring Mechanism Committee 23-24 October 2003 JRC Ispra Overview Inverse modelling Different approaches NAME (langrangian) LOTOS TM Global/Regional Environment http://ccu.ei.jrc.it/ccu/ JRC – Ispra
General lack of measurement data to constrain the emissions Often ill-posed Strong dependence on prior estimates Treatment of model errors How well does the model represent the local situation at the measurement site? Transport, chemistry, wet/dry deposition Two general problems inverse modeling JRC – Ispra
Model Parameters (Fixed) Model Emission Estimates (P) Model parameters are fixed and only the emissions are optimized Model uncertainties might be translated in (wrong) emission estimates JRC – Ispra
urban BC modelling uncertainties: JRC – Ispra
Representation of urban situation Data are sparse, from scattered campaigns in various years Wet removal, the main removal process, is uncertain Long term consistent measurements needed Should the focus be on BC or total carbon? Hard to say if BC emission inventories are high/low, because JRC – Ispra
Courtesy: Alex de Meij JRC – Ispra
Careful selection of representative stations Be aware of model errors (perform sensitivity analysis) Reasonably good perspectives to attempt inverse modeling (e.g. of SO2 emission distribution over Europe) Even If long-term data are available: JRC – Ispra
Use of satellite data JRC – Ispra
Use of satellite data JRC – Ispra
Might provide the data source needed Integrates various species and altitudes But: Aerosol water adds to uncertainties Cloud interference Validation of Satellite products needed Role EMEP measurement network Use of satellite data JRC – Ispra
Methane emission estimates look promising Lack of measurement data Role EMEP measurement network satellite measurements Good perspectives for aerosol (precursors) if: Long term measurements (inter-calibration!) Careful data selection Reduce model errors Satellite products might fill data void Aerosol water / cloud issues Validation Satellite products Conclusions JRC – Ispra