A. Redondas

A.S. Lefohn

B.J. Johnson

D. Shadwick

D.W. Tarasick

E. Cuevas

E.-G. Brunke

F. Schmidlin

G. Zeng

H. Claude

H. Naoe

H.E. Scheel

I. Galbally

J. Davies

J.M. Harris

S. Nichol

S.J. Oltmans

T. Kawasato

T. Nakano

Atmospheric Environment

English

Crossref

Recent tropospheric ozone changes – A pattern dominated by slow or no growth

Oltmans, S.

Lefohn, A.

Harris, J.

Scheel, H. E.

Brunke, E.

Claude, H.

Tarasick, D.

Galbally, I.

Zeng, G.

Johnson, B.

Davies, J.

Koide, T.

Schmidlin, F.

Cuevas, E.

Redondas, A.

Nichol, S.

Shadwick, D.

Patrick, L.

KITopen

Recent Tropospheric Ozone Changes –A Pattern Dominated by Slow or No GrowthSam Oltmans CIRES, University of Colorado andNOAA/ESRL,  Global Monitoring DivisionBoulder, ColoradoAmerican Geophysical Union MeetingDecember 2011Co-authorsA. LefohnJ. Harris H.-E. ScheelE. BrunkeH. Claude D. TarasickI. GalballyG. ZengB. JohnsonJ. DaviesT. KoideF. SchmidlinE. CuevasA. RedondasS. NicholD. ShadwickLaura PatrickWhat is this talk about? What are results from the available data from four decades (~1971-2010) of observations for the longest records? Increasing number of locations that have more than 25 years of observations (surface and ozonesondes).  What are the implications from this record of observations? – Are the records consistent in regions with multiple records? – At what geographic scale can conclusions about trends be drawn (global, hemispheric, regional)?– Are changes related to precursor emissions, transport variability, even climate change?– Has the pattern of change been changing with time?Trends at selected N.H. surface ozone sitesData available for investigating longer-term changes in tropospheric ozone Ozone vertical profile measurements from ozonesondes with the earliest records going back to the late 1960s. Surface ozone observations with the oldest continuing records beginning in the mid 1970s. Particular interest in records that are representative of broad geographic regions. Looking for sites or altitude regions where local effects are minimized (have made some compromises to include several long records). Look at changes by region (northern mid latitudes, high northern latitudes, southern hemisphere) Consider two interesting cases in the NH tropics (Hawaii) and the high Arctic (Barrow, Alaska)High Latitude North AmericaResult: Canadian ozonesonde stationsshow only small changes over 30 years.Result: Spring change may be relatedTo biomass burning in Eurasia.Result: Is there an indication of achange in spring related to climate?Trends in Western EuropeThorough discussion of the changesIn Europe in J. Logan et al., JGR,In press.Result: Most locations in W. Europeshow decreases in the past 10-15 yearsChanges Over the North AtlanticResult: Earlier increase has been followed by  a leveling off in the most recent period.Historical European NOX EmissionsVestreng, V., Ntziachristos, L., Semb, A., Reis, S., Isaksen, I. S. A., and Tarrasón, L.:Evolution of NOx emissions in Europe with focus on road transport control measures, Atmos. Chem. Phys. Discuss., 8, 10697-10747, 2008. Period of Ozone ObservationsChanges in the Eastern United States1971-2010Whiteface 10-year average seasonal variationTrends with altitude at Wallops Island, VirginiaTrends with altitude at Boulder, ColoradoChanges in Western North AmericaChanges in Western North AmericaResult: Weak upward trends haveleveled off.U.S. NO2 Changes (U.S. EPA)Japan Ozonesonde 850-700 hPaAsian NOX EmissionsFrom H. Tanimoto http://www.htap.org/01_2007/presentations/Thursday%20afternoon/Tanimoto-2007%20tfhtap%20tanimoto_MODIFIED.pdf Result: Some recent NOx emission inventories suggest that emission rates maybe slowing. Ozonesondes in Japan have not shown any substantial increasesIn the lower troposphere in the past decade.Trends of Ozonesonde Data (1971-2010) at 3 Stations With Long Records (N.America, Europe, Japan)Changes at mid latitudes of the N.H. Western Europe – Hohenpeissenberg ozonesondes and Zugspitze surface ozone (high altitude Alpine site) North Atlantic - Mace Head, Izana, Bermuda, Iceland surface ozone North America – Eastern U.S. (Wallops Island ozonesondes, Whiteface Mountain surface);Western U.S. (Boulder CO ozonesondes; Glacier National Park, Lassen Volcanoes NP, Rocky Moutain NP, Glacier NP  surface) Japan – Tsukuba and Sapporo ozonesondes ALL THESE REGIONS INDICATE NO SUBSTANIAL INCREASE AND SOME SHOW MODEST DECLINES IN THE MOS RECENT 10-15 YEAR PERIOD. Trends of S.H. surface and Lauder 850-700 hPa ozonesonde dataSeasonal variation of surface ozone atCape PointLauder TrendwithaltitudeChanges in the Southern Hemisphere There have been significant increases at mid latitudes of the southern hemisphere. There may be a slowdown of the increases in the most recent decade. In the S.H. tropics and polar regions the changes have been small. Understanding of changes is minimal.  The observational network in the S.H. is not adequate to demonstrate the overall pattern of change.Spring Change in the High Arctic (Barrow)March 1988 March 2008March 2009 March 2010Trends with altitude at Hilo, HawaiiMauna Loa Hawaii10-year average seasonal variation 1982-2010Decadal air flow patterns to Hawaii influence ozone.- Northerly flow: high ozone (2001-2010)- Southerly flow:low ozone (1981-1990)Sep.-Oct. 1986-1994 Sep.-Oct. 1995-2004More flow from the SouthMore flow from the North2001-20101981-1990High ozone decadeLow ozone decadeNortherly flowSoutherly flowMLO OzoneTrajectory statistics Trajectory statisticsConclusions In the N.H. there is a somewhat different pattern of long-term changes between N. America, Europe, and Japan. Over N. America earlier increases (primarily before 1990) have become small to moderate declines.  Western Europe saw the largest increases prior to 1990 but a significant decrease in growth rates  (and in some cases declines) over the past 15 years over continental Europe. In Japan increases were primarily prior to the mid 1980s, but with recent increases in Okinawa. In Hawaii (N. Pacific tropics) increases Conclusions (continued)The tropical south  Pacific (Samoa) has not shown significant changes in  tropospheric ozone. In the S.H. mid latitudes, at Cape Point, Cape Grim, and Lauder ozone has increased significantly.At South Pole earlier declines have reversed so that overall there has been almost no change. Some possible implications of recent (30-year) observed changes The relationship between emission changes and longer term hemispheric and global tropospheric ozone changes is not adequately understood. The climate forcing of tropospheric ozone changes over the recent past is and in the future is still very uncertain. It will be difficult to assess the climate forcing reductions that can be gained by reducing tropospheric ozone with the current network of observations. 

Recent tropospheric ozone changes. A pattern dominated by slow or no growth

https://publikationen.bibliothek.kit.edu/230089703/3816225

Recent tropospheric ozone changes. A pattern dominated by slow or no growth

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