Slide 1

Links of the Mediterranean Oscillation to mid-latitude and tropical climate dynamics Jucundus Jacobeit, Stephanie Seubert, Armin Dnkeloh University of Augsburg Slide 2 Conte et al. 1989 Correlations of the Mediterranean annual mean 500 hPa geopotential heigths with those of Algiers (inside the dotted lines: statistically significant at the 95% level of confidence) + _ Slide 3 Conte et al. 1989 Pattern of the 500 hPa heights at the stations of Algiers and Cairo (8th order polynominal smoothing and superimposed linear trend) Algiers Cairo 500 hPa (m) Slide 4 Pattern of the 500 hPa heights at the stations of Algiers and Cairo (with superimposed linear trend and 8th order polynominal smoothing) Palutikof 2003 (after Conte et al. 1989) Slide 5 Conte et al. 1989 Mediterranean Oscillation Index Slide 6 Mediterranean Oscillation Index (Conte et al. 1989): Difference of normalized geop. height anomalies at Algiers and Cairo Mediterranean Pressure Index (Palutikof 2003): Difference of normalized pressure anomalies at Gibraltar and Lod Mediterranean Circulation Index (Brunetti et al. 2002): Difference of normalized pressure anomalies at Marseille and Jerusalem Slide 7 Luterbacher et al. 2002: Objectively reconstructed North-Atlantic-European grids of SLP and 500 hPa geopotential heights, early versions of temperature and rainfall grids since 1659 with monthly resolution Slide 8 MO since 1660 winter (DJF) Algiers/ Cairo Gibraltar/ Lod Marseille/ Jerusalem Slide 9 Representation of the MO by large-scale circulation patterns Slide 10 first canonical correlation patterns for winter 500 hPa level 1000 hPa level Precipitation 20.1% 30.4% Dnkeloh & Jacobeit 2003 r = 0.60 with AO r = 0.72 with NAO r ~ 0.80 with various MO indices ONDJFM 1948-98 Slide 11 Smoothed time coefficients of the first canonical correlation patterns for winter Dnkeloh & Jacobeit 2003 r = 0.92 Slide 12 first canonical correlation patterns winter (DJF) 1660-1990 SLP EV = 21.1% Precipitation EV = 14.6% Slide 13 first canonical correlation patterns for winter (DJF) 1660-1990 500 hPa EV = 11.7% Precipitation EV = 13.4% r ~ 0.7 with various MO indices r = 0.50 with NAO Slide 14 winter (DJF) 1660-1990 Smoothed time coefficients of the first canonical correlation patterns r = 0.89 Slide 15 Dnkeloh & Jacobeit 2003 r = 0.85 p = 0.000 EVgpot = 10.5 % EVprec = 19.8 % 500 hPa level 1000 hPa level second canonical correlation patterns precipitation r ~ 0.5/0.6 with various MO indices r = 0.55 with NAO spring (AM) Slide 16 Dnkeloh & Jacobeit 2003 Smoothed time coefficients of the second canonical correlation patterns for spring r= 0.85 Slide 17 Dnkeloh & Jacobeit 2003 r = 0.67 p = 0.000 EVgpot = 12.2 % EVprec = 10.1 % 500 hPa level1000 hPa level second canonical correlation patterns precipitation r < 0.4 with various MO indices r = 0.45 with NAO summer (JJAS) Slide 18 Dnkeloh & Jacobeit 2003 Smoothed time coefficients of the second canonical correlation patterns for summer r= 0.67 Slide 19 third canonical correlation patterns summer (JJAS) 1660-1990 500 hPa Precipitation Slide 20 Seasonal correlation coefficients between NAO and MO: Winter: 0.72 Spring: 0.37 Summer:(-0.13) Autumn: 0.30 (with Gibraltar/Lod, from Palutikof 2003) Slide 21 Conclusions Part I: The MO is strongly linked to the NAO during winter, this relationship fades away towards summer and recovers afterwards in terms of canonical correlation patterns, the MO patterns show - from winter to summer - a gradual weakening with respect to CC coefficients and % of explained rainfall variances within this seasonal sequence, the MO is primarily an upper-level phenomenon Slide 22 March to November 1951-2000 Domain: 20S 70N, 90W 150E Teleconnection studies (Stephanie Seubert ): Slide 23 Diagram of seasonal sections for the period March to November: 45 seasonal sections including 1-month up to 9-month sections Length of seasonal section (number of months) Starting month of seasonal section Current number of seasonal section Slide 24 Slide 25 1000 hPA 850 hPA 500 hPA 250 hPA 100 hPA Teleconnection - PCA cases: grid points Input variables: correlation maps of 15 regional prec-indices and 45 seasonal sections 5 levels 1 3589 Varimax-rotated, multi-level PCA: Extraction of 9 teleconnection PCs Loadings: Correlation coefficients between PC-Scores and correlation maps Scores: Major teleconnection patterns 1 3589... Slide 26 Leading teleconnection mode (TPC 1) 1000 hPA 500 hPA 250 hPA EV = 23 % Slide 27 Loadings of TPC 1 for the 15 prec.-indices and the 45 seasonal sections (=0.01) Slide 28 Affinities between ENSO and the MO (JJAS) Eastern Medit. 3 MOI NINO3.4 TPC 1 Iberian Peninsula Correlations with 250 hPa level Slide 29 Pearson Correlation between MOI and NINO3.4 -0.73 for JJAS Slide 30 Pearson Correlations for all the 45 seasonal sections between NINO3.4 and different indices of the MO Slide 31 Algiers/ Cairo Gibraltar/ Lod Marseille/ Jerusalem 1000 hPa 500 hPa Slide 32 Correlations of MOI (500) with geopotential heights JJASO 1000 hPa 850 Pa 500 hPa 250 hPa 100 hPa Slide 33 Correlations of MOI (1000) with geopotential heights JJASO 1000 hPa 850 Pa 500 hPa 250 hPa 100 hPa Slide 34 Correlations of NINO 3.4 index with geopotential heights JJASO 1000 hPa 850 Pa 500 hPa 250 hPa 100 hPa Slide 35 Conclusions Part II: There are indications for ENSO impacts on the MO: with negative sign for late summer/early autumn with positive sign for spring Opposite centres in the western and the eastern Mediterranean are confined to the lower troposphere, in the upper troposphere there is a change of sign above the eastern Mediterranean Slide 36 Links of the Mediterranean Oscillation to mid-latitude and tropical climate dynamics Jucundus Jacobeit, Stephanie Seubert, Armin Dnkeloh University of Augsburg