Observations and model calculations in support of the analysis of intercontinental transport of air pollution Øystein Hov Norwegian Meteorological Institute also at Dep of Geosciences, University of Oslo TFHTAP EMEP-WMO Workshop Geneva 24-26 January 2007
Outline of presentation Evidence for intercontinental transport Change in ozone, PM, S- and N-deposition over Europe, how much can be accounted for by intercontinental transport of man-made pollutants? Competing factors: Changes following intracontinental man-made emission changes (policy measures; population growth; economic growth, migration to cities) Changes due to biomass burning Changes due to climate change Changes in land-use/surface-atmosphere fluxes (H 2 O, N, C) Lessons learned from numerical weather prediction What can WMO contribute to the analysis of intercontinental transport?
Observational evidence for intercontinental transport
SCIAMACHY Tropospheric NO 2 pollution Ensemble of individual events (episodes) aggregated over three years biomass burning Andreas Richter University of Bremen
POLDER instrument Aerosol Index March-May 1997 Polarization and Anisotropy of Reflectances for Atmospheric Science coupled with Observations from a LIDAR POLDER is a push broom, wide field of view, multi-band imaging radiometer/polarimeter, 114-degree wide field of view, 7km x 6km footprint From Volker Mohnen
Tropospheric SO 2 : The global View 7 years Compared to NO 2, SO 2 columns have larger uncertainties: low signal (UV) small sensitivity to boundary layer strong interference by O 3 absorptions Andreas Richter University of Bremen 3 years
SCIAMACHY WFDOAS - CO columns 2004 March-April Jan-Feb July_Aug May-June Buchwitz et al 2006 University of Bremen Sept-Oct Nov-Dec Zentrum für f r Marine und Atmosphärenwissenschaften, Universität t Hamburg, 11 Januar 2007
To what extent is there intercontinental transport of manmade precursors (S, N), ozone or (inorganic) aerosols?
Emissions and removal over Europe 2000 S and N SO 2 emissions 10,00 MtS S dep 8,88 MtS 89% NO x emissions 5,92 MtN Oxidised N deposition 5,10 MtN 86% NH 3 emissions 5,08 MtN Reduced N deposition 4,99 MtN 98% S and N emissions in Europe are deposited inside Europe EMEP Report 1/2003
EMEP hemispheric model calculations sourcereceptor relationships between continents Polar stereographic grid 100x100km 2, 20 layers up to 100hPa, 8 layers below 2km ECMWF ERA-40 meteorology for 2001 Edgar 2000 emission data EMEP-MSCW Technical Report 2/2006
Average reduction in ozone (ppb) 2001 resulting from 15% VOC or 15% NOx emission reduction 15% VOC emission reduction 15% NOx emission reduction Emitters Receptors Western Europe North America Far East Middle East Western Europe North America Far East Middle East Western Europe North America 0.41 0.06 0.05 0.08-0.06 0.02 0.02 0.04 0.10 0.18 0.04 0.05 0.14 0.63 0.06 0.06 Far East 0.05 0.06 0.26 0.05 0.04 0.07 0.65 0.05 Middle East 0.01 0.01 0.03 0.20 0.02 0.01 0.06 0.70 <25% EMEP MSCW Technical Report 2/2006
Average reduction in secondary inorganic aerosol in 2001, in µg/m 3 resulting from - 15% SO2 emission reduction, - 15% NOx emission reduction, 15% SO2 emission reduction 15% NOx emission reduction Emitters Receptors Western Europe North America Far East Middle East Western Europe North America Far East Middle East Western Europe North America 0.29 0.00 0.00 0.04 0.22 0.00 0.00 0.01-0.00 0.15 0.00 0.00 0.01 0.09 0.00 0.00 Far East 0.00 0.00 0.38 0.02 0.00 0.00 0.17 0.00 Middle East <5% 0.01 0.00 0.02 0.35 0.00 0.00 0.01 0.12 EMEP MSCW Technical Report 2/2006
Average change in wet and dry deposition in 2001 of - oxidised sulphur (kts) from 15% SO2 emission reduction, - oxidised nitrogen (ktn) from 15% NOx emission reduction 15% SO2 emission reduction 15% NOx emission reduction Emitters Receptors Western Europe North America Far East Middle East Western Europe North America Far East Middle East Western Europe North America 640 0.2 13.2 14.6 377 1.8 9.9 6.5 1.9 1302 0.5 0.2 10.5 680 7.6 2.5 Far East 1.5 2.0 2954 2.9 2.2 6.2 976 2.6 Middle East <3% 18.8 0.2 79.9 255 5.4 0.9 29.4 126 EMEP MSCW Technical Report 2/2006
Change in ozone, PM, S- and N-deposition over Europe, how much can be accounted for by intercontinental transport of manmade pollutants? Competing contributors to European ozone change : Changes following intracontinental man-made emission changes (policy measures; population growth; economic growth, migration to cities) Changes due to biomass burning Changes due to climate change Changes in land-use/surface-atmosphere fluxes (H 2 O, N, C)
MEAN SURFACE OZONE INCREASE BY MAN-MADE NO x AND VOC EMISSIONS IN NORTH AMERICA, EUROPE AND ASIA 2-3ppb GEOS-CHEM model, July 1997 North America Europe Asia Li et al. [2002]
Emissions Emissions in Europe reduced from 1990 2002 North American Emissions of NO x and VOC reduced by ~15 20% Asian Emissions increasing Anthropogenic emissions in Mt/year 1990 NOx VOC CO EU25 15991 16869 61213 Czech Rep. 544 441 1257 UK 2771 2419 7417 Germany 2845 3591 11212 N. America 25775 21264 97651 2002 NOx VOC CO EU25 10988 10322 33774 Czech Rep. 318 203 546 UK 1582 1186 3238 Germany 1499 1478 4311 N. America 21721 17790 111562
Ozone trends at Mace Head ARTICLE IN PRESS P.G. Simmonds et al. / Atmospheric Environment 38 (2004) 4769 4778 4773 Clean sector important to note that any increase or decrease in the concentrations of O 3 over Europe will be incorporated into the rising levels of background O 3. In fact, Wotawa et al. (2000) have shown that higher net O 3 production over Europe could not be attributed solely to European emissions and that changes in background O 3 must also be considered. To illustrate this we can obtain a more accurate picture of the changing pattern of O 3 over continental Europe by subtracting the background monthly means from the polluted monthly means as shown in Fig. 3. Interestingly, this plot shows evidence of a tendency towards decreasing photochemical O 3 production during the summertime in regionally polluted air masses arriving at Mace Head. This tendency has been observed elsewhere in northwest Europe over the same period (Derwent et al., 2003; TOR-2, 2003). 25 20 15 10 5 0-5 -10-15 -20-25 Jan-87 Jan-88 Jan-89 Jan-90 Jan-91 Jan-92 Jan-93 Jan-94 Jan-95 Jan-96 Jan-97 Jan-98 Jan-99 Jan-00 Polluted-Unpolluted monthly means (ppb) Jan-01 Jan-02 Jan-03 Jan-04 Fig. 3. Polluted O3 monthly means baseline O3 monthly means. 50 OZONE CONC ( PPB) 45 40 35 30 25 1986 1988 1990 1992 1994 1996 1998 2000 2002 2004 SPRING WINTER SUMMER AUTUMN Fig. 4. Seasonal trends in Mace Head O3 baseline monthly means. From Simmonds et al. (2004)
observation model 1990 2002 Change in central Europe controlled by reduction in European emissions and increase in BC
Climate change-like conditions change pollution load (summer 2003)
Schär et al., 2004, Nature 427,
Schär et al., 2004, Nature 427, 332-336
JJA 2003 RCM climate change scenario of current (CTRL 1961 90) and future (SCEN 2071 2100) conditions. a, b, distribution of summer T northern Switzerland for CTRL and SCEN, c, T for SCEN CTR, d, Change in variability expressed as relative change in standard deviation of JJA means ((SCEN CTRL)/CTRL, %). Copied from Schär et al., 2004.
Oslo CTM surface ozone 1-15 August 2003 (Søvde, Hov, Isaksen, 2007)
Climate change feedbacks on atmospheric composition can be sorted according to emission regulators (both anthropogenic and biogenic, including demography, shift in seasonal temperatures and the effect on energy consumption, plant and forest species, atmosphere-ocean interaction) transport regulators (wind, convection, mixing properties in the ABL) transformation regulators (rh, q, cloud cover and type, T, albedo and its effect on photolysis rates) removal regulators (precipitation frequency and amount, surface properties, bidirectional effects)
Surface ozone UiO CTM Søvde, Hov and Isaksen 2007 2003 50 ppb
Biomass burning contributions to pollution load change
BIOMASS BURNING EFFECT AZORES
Pico observations (NOAA site 2200 m a s l on the Azores) Ozone frequency distribution in Northern North American flow; non-fire shaded, fire unshaded http://www.cee.mtu.edu/~reh/pico/pico.html#pub:fehsenfeld06 25ppb
Educated guess of factors contributing to European surface ozone (similar discussion can be made for PM) ozone in Europe HTAP - man made emissions season 2-4ppb Climate change 5-10ppb for JJA, 10-20 ppb for one month (high number rare) 1000x1000km 2 Biomass burning Surfaceatmosphere exchange Megacity/hotspot expansion (migration) 5-10ppb for parts of the continent? 5ppb enhancement in drought, extending over dry region broader pdf of seasonal ozone? Δglobal methane 1-2 ppb 1-2 ppb episode 1-14 d duration 5-10 ppb over a few days over a limited region 20-50ppb up to a week over 1000x1000 km 2 (high number very rare) 20ppb up to a week over 1000x1000km 2? 20ppb over a week or two in drought, extending over dry region? more people in megacities discretisize emissions rarer but more severe LRT episodes? (lifting must be efficient over megacity)
Lessons learnt from numerical weather analysis/prediction Intercontinental transport following convective lifting of polluted air above source regions Rapid ascent ahead of a cold front (WCB)
Number of Northern Hemisphere Cyclones T255 ERA T159 T95 WMO WGNE M Muller & Jung 2006
WMO-WGNE M Muller ECMWF 2006) Diurnal Cycle: Local time of maximum precipitation Satellite Observations Yang and Slingo, 2001, MWR Model Simulation
Contributions to TFHAP-issues from WMO
WMO contribution to TFHTAP WMO integrates regions (local and regional air pollution important driving forces): EMEP, EU, EANET, N America, Atmospheric Brown Cloud, Greying of Europe. WIS Maintains GAW and funding streams and commitment through NMSs (operationality) has the global scale needed to address the anthropogenic modification of many biogeochemical cycles has a model of how to fuse complex data streams according to the user needs as expressed by NMSs (cfr NWP; GMES/GEOSS)
Air Pollution/Environmental Technology Laboratory GAW 2005, Geneva
Air Pollution/Environmental Technology Laboratory GAW 2005, Geneva
IMPLEMENTATION OF GAW-IGACO-STRATEGY
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