Oscillation Patterns in RegCM4 Contents Teleconnections & - PowerPoint PPT Presentation

C LIMATE R ESEARCH IN THE D EPARTMENT OF P HYSICS J. Ciarlo`, M ALTA C LIMATE T EAM 14-19 th March 2011

How Oscillation Patterns effect one another How Oscillation Patterns effect aerosol transport Oscillation Patterns in RegCM4

Contents  Teleconnections & Oscillation Patterns  Aerosols & Transportation  Patterns, Indices & the Domain  Measured Data  Teleconnection Analysis  From Measured Data  RegCM4  Aerosol Transport  Conclusions 3

Teleconnections & Oscillation Patterns  Teleconnection:  Two or more distant points of air pressure – “nodes”  Icelandic Low – 3600 km – Azores High  Strong Negative Relationship  Oscillation Pattern:  The teleconnection as a whole, varies almost in an oscillating manner.  The North Atlantic Oscillation (NAO) 4

Aerosols & Transportation  Aerosols:  Solid and Liquid particles suspended in air.  Transportation:  Movement of particles through air motion.  Air Movement: Cold Air Hot Air High Pressure Low Pressure Centre Centre 5

Patterns, Indices & the Domain 6

Patterns, Indices & the Domain Indices quantify the state of a Pattern  Difference in pressure at sea level (or geopotential height at pressure level).  The difference is standardized with long term monthly means.  Result: Index value varying from +3 to -3. 7

Patterns, Indices & the Domain The influence of Oscillation Patterns  Example: The North Atlantic Oscillation NAO- NAO+ 8

Measured Data Sea Level Pressure Higher Altitude Pressure  Used to extract pressure values for the nodes to construct Oscillation Indices. u-wind – wind component in the west to east direction. v-wind – wind component in the south to north direction.  Necessary for studying wind vectors & understanding wind motion. 9

Teleconnection Analysis: From Measured Data  Influence of Oscillation Patterns on Wind activity  North Atlantic Oscillation (Walker & Bliss, 1935) 10

Teleconnection Analysis: From Measured Data  Influence of Oscillation Patterns on Wind activity  Central African-Caspian Oscillation (Kutiel & Helfman, 2004) 11

Teleconnection Analysis: RegCM4 North Atlantic Oscillation Index (Walker & Bliss, 1935) North Atlantic Oscillation Index (Walker & Bliss, 1935) RegCM4 NCEP RegCM4 NCEP  Correlation: 0.87 3 3 2 2 1 1 Index Value 0 Central African-Caspian Oscillation (Kutiel & Helfmann, 2004) Index Value RegCM4 NCEP 0 4 -1 3 -1 -2 2 -3 1 -2 Index Value 0 -3 -1 -2 -3 -4 12

Teleconnection Analysis: RegCM4 North Atlantic Oscillation Index (Walker & Bliss, 1935) RegCM4 NCEP 3 2 Central African-Caspian Oscillation (Kutiel & Helfmann, 2004) 1 RegCM4 NCEP 4 Index Value 0 Central African-Caspian Oscillation (Kutiel & Helfmann, 2004) 3 RegCM4 NCEP 4 -1 2 3 -2 1 2 Index Value -3 1 0 Index Value 0 -1 -1  Correlation: 0.39 -2 -2 -3 -3 -4 -4 13

Teleconnection Analysis: Aerosol Transport  Considering dust (smaller than 0.1 μ m)  Understanding the regions of highest occurrence 14

Conclusions 15

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E: jcia0004@um.edu.mt 17