NESTED GRID APPLICATION OF GEOS-CHEM OVER EUROPE A. Protonotariou 2, P. Le Sager 1,3, M. Tombrou 2, C. Giannakopoulos 1 3 rd GEOS-CHEM User’s Meeting – Harvard 3, April 11-13, : National Observatory of Athens, Greece 2: National and Kapodistrian University of Athens

Scope Compare GEOS-CHEM nested grid formulation results with :  results from the global GEOS-CHEM model  observations Study Carbon Monoxide (CO) at surface over Europe Apply the GEOS-CHEM nested grid formulation over Europe National Observatory of Athens, Greece National and Kapodistrian University of Athens

Wang et al. [2004] GEOS-CHEM They first modified and applied the GEOS-CHEM nested grid over Asia in a CO only application (spring 2001) Li et al. [2005] North America - Full chemistry nested grid simulation (summer 2000) National Observatory of Athens, Greece National and Kapodistrian University of Athens GEOS-CHEM GEOS-CHEM previous nested grid studies

Simulations: LO LO LO ( LO w Resolution): Global full chemistry run 4 0 x5 0 horizontal grid resolution Runs for two-year period ( ) Results for the second year (1-y model spin-up) Save boundary concentrations around nested window HI HI HI ( HI gh Resolution): Nested grid - full chemistry over Europe 1 0 x1 0 horizontal grid resolution Run for 2001 over Europe Boundaries from global run (LO) Vertical levels as in LO Nested grid of GEOS-CHEM over Europe Geos-Chem : v Met. data : GEOS-3

Nested grid of GEOS-CHEM over Europe LO LO: Global simulation (4 0 x5 0 ) HI HI: Simulation in Europe Nested window (1 0 x1 0 )

Differences in the representation of the spatial scales for significant changes in terrain  Depiction of a number of specific topographic features i.e. Alps  Coasts  Higher altitudes for HI 1630 m m LO (4 0 x5 0 ) HI (1 0 x1 0 ) Terrain heights

National Observatory of Athens, Greece National and Kapodistrian University of Athens Spatial distribution of monthly mean CO mixing ratios Results: CO mixing surface

520 [ppbv] [ppbv] HI LO Monthly mean CO mixing ratios - January 2001 diff: LO - HI % diff: LO - HI 100 [ppbv] [%] Central Europe Central Europe: Germany The Netherlands U.K Eastern Europe: Russia High polluted areas HI depicts patterns in detail HI predicted higher values Max diff. 180ppbv /40% Max. diff. : 180ppbv Max. diff. 40%

Anthrop. emissions (LO)Anthrop. emissions (HI) 520 [ppbv] [ppbv] Tg HI LO Anthrop. Emissions (HI) Anthrop. Emissions (LO) Monthly mean CO mixing ratios vs emissions January 2001 Highest CO mixing ratios indicate for regions of high anthro emissions

Monthly mean CO mixing ratios - July 2001 HI LO diff: LO - HI % diff: LO - HI 520 [ppbv] [ppbv] [ppbv] [%] Max. diff. : 100ppbv Max. diff. 35% Lower diff. between HI and LO in comparison to winter CO lower compare to winter => Follows CO annual cycle

Monthly mean CO mixing ratios - July 2001 HI LO Lower CO concentrations over Europe in summer Anthrop. Emissions (HI) Anthrop. Emissions (LO)

Airbase :( 31 rural background stations over Europe in:  France  The Netherlands  Germany  Austria  Italy  Switzerland  Poland National Observatory of Athens, Greece National and Kapodistrian University of Athens

HI>LO emission rate HI>LO HI<LO emission rate HI<LO HI LO Correlation depends on the emissions in a grid Higher emissions => higher concentrations HI vs LO mixing ratios

LOHI Observations: black boxes - LO: black solid line - HI: Red: winter/ Blue: spring/Green: summer/Purple: autumn Daily average CO mixing ratios for 2001

At most stations LO and HI reproduced very well: the high CO mixing ratio levels in winter Very good representation of CO annual cycle => Very good representation of CO annual cycle the low CO mixing ratio levels in summer HI LO

Red: winter Blue: spring Green: summer Purple: autumn vs Scatter plots : Model vs Observations X/Y axis :1000ppbv Observations HI HI (1 0 x1 0 ) HI Most of the simulated values for HI lie around the 1:1 line, indicating a very good agreement between the model simulations and the observations.

Full yearWinterSpringSummerAutumnFull yearWinterSpringSummerAutumn Observation Mean est SD of obs ModelHILO Mean est SD of model MB ME NMB (%) NME (%) MFB (%) MFE (%) RMSE Mean bias (ppbv) and normalized mean bias (%) show the under- or over- estimation. These metrics assume observations are the absolute truth (Boylan and Russel, 2005) Seasonal performance In winter & autumn the model underestimated the observations In spring & summer the model overestimated the observations LOHI Largest underestimation : in winter for LO ( 13.58ppbv ) HI performs better (11.64ppbv) LOHI Largest overestimation is in summer for LO ( 10.77ppbv). HI performs better ( 7.57ppbv ) Red: winter Blue: spring Green: summer Purple: autumn Statistical analysis

LOHI Observations: black boxes - LO: black solid line - HI: Red: winter/ Blue: spring/Green: summer/Purple: autumn Good correlation: all stations in Netherlands LO : R 2 = HI : R 2 = Poor correlation all stations in France LO : R 2 = HI : R 2 =

STATISTICAL ANALYSIS Full year for one station in NL HI MB=11.72ppbv NMB=4.55% LO LO MB=-50.26ppbv NMB=-19.49% R 2 =0.68 R 2 =0.45

16-18 January 2001 Hourly data Example for a selected station in NL

Conclusions HI GEOS-CHEM nested grid formulation over Europe (HI) reproduces very well the CO concentrations and CO annual cycle The largest differences in maximum CO mixing ratios between the GEOS-CHEM nested grid and global simulation were found over : a) the areas with the higher anthropogenic emissions b) in rural areas located close to large industrial areas These discrepancies become more obvious during the winter when the limited atmospheric mixing prohibits the primary pollutants from the wider vicinity.

Conclusions (continued) HI showed a very good correlation for most of the stations Large differences between HI and LO for individual cases T he nested grid run HI shows in winter an ability to simulate more accurate the higher values HI shows a better performance for all seasons in comparison to LO National Observatory of Athens, Greece National and Kapodistrian University of Athens

Future work o Complete the nested grid study for O 3 Done: Literature review, measurements from network in Europe, Tagged Ox o Future climate runs –emission scenario for 2100 –changes in temperature provide useful info for changes in chemistry in a climate change world oTagged CO in nested grid: to estimate contribution from all sources and transport -- Emission shut off ->done o Comparison to satellite results o Vertical profiles

A little info about us... Anna Protonotariou MSc. Environmental Physics, PhD candidate, UOA Department of Applied Physics, University of Athens, Greece Philippe Le Sager Research Associate Division of Engineering and Applied Science, Harvard University, U.S.A Maria Tombrou Assistant Professor, UOA Department of Applied Physics, University of Athens, Greece Christos Giannakopoulos Researcher, Institute for Environmental Research and Sustainable Development National Observatory of Athens Thank you !!

References  Bey I., D. J. Jacob, R. M. Yantosca, J. A. Logan, B. Field, A. M. Fiore, Q. Li, H. Liu, L. J. Mickley, and M. Schultz, (2001a), Global modeling of tropospheric chemistry with assimilated meteorology: Model description and evaluation, J. Geophys. Res., 106, 23,073-23,096  Boylan, James W. and Armistead G. Russell, 2006: PM and light extinction model performance metrics, goals, and criteria for three- dimensional air quality models. Atmos. Env.. 40,  Li, Q., D. Jacob, R. Park, Y. Wang, C. Heald, R. Hudman, R. Yantosca, R. Martin, and M. Evans, North American pollution outflow and the trapping of convectively lifted pollution by upper-level anticyclone, J. Geophys. Res., 110, D10301, 2005  Wang, Y., M.B. McElroy, D.J. Jacob, R.M. Yantosca, A nested grid formation for chemical transport over Asia: applications to CO, J. Geophys. Res., 109, D22307, oi: /2004jd005237, 2004 National Observatory of Athens, Greece National and Kapodistrian University of Athens