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Indo-Pacific OLR variations

Indo-Pacific OLR variations. This viewpoint may relate more to OLR background and less to OLR spectral peak due to MJO The global wind oscillation (GWO) monitors the ups and downs of the atmospheric angular momentum

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Indo-Pacific OLR variations

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  1. Indo-Pacific OLR variations • This viewpoint may relate more to OLR background and less to OLR spectral peak due to MJO • The global wind oscillation (GWO) monitors the ups and downs of the atmospheric angular momentum • The seasonal base state, location of mountains and eddy momentum transports across 35N are important components of zonal mean GWO variations. • Global teleconnection patterns link the GWO orbits to tropical convection over the Indo-Pacific Ocean • More relevance to forecasting than DYNAMO field project, …….but could get year like 2008-09!

  2. Western Pacific uwind incrsg ~10N N Ind to 30N Pac Oc Subtropical wave 1 prior to circ reversal H 30N 10N L L H L L H H L 20N West. Hem. And Africa Maritime Continent El-Nino La-Nina u’>0 on EQ WHemi moving east & north 20N L H 30N 10N H L L H H L H Indian Ocean

  3. Date Line El-Nino southward transport 35N; NW-SE tilts; CWB L WH/ Africa L H L H cyclones subtropics & mid-lats 35N w P a c east wind anoms over mountains, sfc westerlies shift south M>0 F<0 max positive AAM tendency max negative AAM tendency e I O M<0 F>0 west wind anoms over mountains, trade winds shift north anticyclones subtropics & mid-lats BWPs develop & become NE-SW 35N H northward transport 35N; NE-SW tilts; AWB H L H L La-Nina wIO

  4. GWO Activity Jul-Aug 2007 Feb-Mar 2005 MJO Activity Dec-Jan 2008 Mar-Apr 2005 Dec 2006 Sep-Oct 2008 1997 1999 2001 2003 2005 2007 2009

  5. MJOs MJOs: GWO initiation followed by better MJO MJOs large signal developing

  6. MJO_totanom Phase Space Signals Sep-Mar 2009 Sep- 15 Mar ‘09 196 days • ENSO produces: • persistence in phases 3-4 • truncated MJO • GWO produces: • irregular variations • betwn phases 3 & 4 • active MJOs: • 1 Sep - 25 Oct ‘08 • 20 Dec - 5 Feb ’09 • 05 Mar – present X (11 April)

  7. 26 December 2008 Key date for MJO development How soon can models predict initiation vs propagation of signals? H L H H L L L L H H H

  8. GWO Phase Space Signals Sep-Mar 2009 Phase 8-1 Phase 4-5 Phase 2-3 Phase 6-7 ENSO produces: Difference in centroid of Nov 08 versus Feb 09 orbits GWO produces: 25-30 dy “cycles” phase 1/2 <=> 4 MJO is present: 1 Sep - 25 Oct 08 (couples with GWO) 20 Dec - 5 Feb 09 (forced by GWO?) 05 Mar – present (forced by GWO?) Nov ‘08 Feb ‘09 “breakouts” initiated by momentum sink events at southern periphery of jet

  9. GWO 07 08 09 MJO 07 08 09 DJF 2009 - JJA 2008 + - + eddies torques

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