1 / 25

Mike Groenke (Atmospheric Sciences Major)

MICHAEL A. ALEXANDER , ILEANA BLADE, MATTHEW NEWMAN, JOHN R. LANZANTE AND NGAR-CHEUNG LAU, JAMES D. SCOTT. The Atmospheric Bridge: The Influence of ENSO Teleconnections on Air–Sea Interaction over the Global Oceans. Mike Groenke (Atmospheric Sciences Major).

adair
Download Presentation

Mike Groenke (Atmospheric Sciences Major)

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. MICHAEL A. ALEXANDER, ILEANA BLADE, MATTHEW NEWMAN, JOHN R. LANZANTE AND NGAR-CHEUNG LAU, JAMES D. SCOTT The Atmospheric Bridge: The Influence of ENSO Teleconnections on Air–Sea Interaction over the Global Oceans Mike Groenke (Atmospheric Sciences Major)

  2. El Nino-Southern Oscillation (ENSO) • Tropical Pacific region • Associated sea surface temperature (SST) anomalies • Warm=El Nino…Cold=La Nina • ENSO events drive ocean SST anomalies around globe • “Atmospheric bridge” because connects the world’s oceans

  3. Better explanation • http://www.youtube.com/watch?v=IvmeUStFvz8

  4. Q-net: net surface heat flux • We=entrainment heat flux • Vek=Ekman transport

  5. Wait, why do we care? • Essential for prediction of SSTs in tropical Atlantic • Contributes to leading patterns of SSTs on many times scales around globe • Tests ability to simulate global atmospheric response to ENSO • Separate between atmospheric forcing and ocean feedbacks • Influence on marine ecosystems

  6. ENSO Really Matters

  7. Questions that remain • Ocean-atmosphere interactions via changes in solar radiation, precipitation, and boundary layer processes. • Indian Ocean response to ENSO • Feedback from SST anomalies beyond equatorial East Pacific

  8. Purpose of this study • Review of how well we understand the “atmospheric bridge” • Present new data/observations • Focus on Pacific North America (PNA) region

  9. Modeling Used • 3 major models were used • “Control model” • “MLM” or mixed layer model • “NP-MLM” or North Pacific mixed layer model • NCEP-NCAR re-analysis project data also used

  10. Methods • Look at observations from past • Interpret data and form hypotheses and assumptions • Run models and look for reproduction of observed data • Interpret results

  11. Main Focus • Global precipitation influences from ENSO • Related SST anomalies on different times scales around the globe • Relationship between SST and SLP

  12. Effects On Global Precip • Changes in jet stream speeds from ENSO • Anomalous clockwise flow=higher precip

  13. ENSO Felt Around the World SST Anomalies • North Pacific • Opposite sign of ENSO • Pacific Decadal Oscillation influenced by tropical and extra-tropical forcing • Far north near “sub arctic front” not correlated

  14. Current Example

  15. ENSO Felt Around the World • Tropical Atlantic: • Warm waters just north of equatorial Atlantic found with El Nino in spring after ENSO peak • Southern Atlantic only weak links plus 3-6 months lag time • Indian Ocean • Warms with El Nino • Lag time of 3-6 months, but earlier than Atlantic • Often during summer/fall also

  16. Relationship in SLP & SST’s • Stronger Aleutian low (by 9mb) during Nino vs. Nina • Causes increased westerlies in north Pacific • Advects cold air into northern waters and warm air along west coast of North America • Consistent with previous SST map • Model differences likely due to error and missing ocean dynamics Figure on next slide!!

  17. Check out the pressure! Observed MLM Simulation

  18. Shaded areas indicated a 95% statistical significance in difference between taking local coupling effects into account or not

  19. Other ENSO Induced Effects • MLD (Mixed Layer Depth) • The depth at which the temperature is 1 degree C cooler than the surface • Salinity • Reemergence of SST anomalies • Fades during summer, but effects next winter

  20. Summary • Atmospheric response to changes in SST’s due to ENSO influences conditions across the rest of the globe • This connection is called the “Atmospheric Bridge” • Clear link in ENSO SST anomalies and other anomalies in Northern Pacific, north tropical Atlantic, and Indian Oceans • Atmospheric response affects SLP and jet stream patterns across the globe including deep trough near Alaska

  21. Summary (cont’d) • Other impacts include effects on MLD, salinity, and the reemergence of anomalies during the following year • Changes in net heat flux are the leading driver of SST anomalies in the ENSO region • Ocean-air coupling modifies effects on pressure fields in the North Pacific

  22. My Thoughts • Good review of impacts from El Nino/La Nina events • Too many assumptions that reader knows extremely technical processes • Further research in this field could improve seasonal forecasting • Lacked significant mention of effects from climate change

  23. Questions?

More Related