Yan Xue, Boyin Huang Climate Prediction Center Janine Fisler

1. Exploring the Potential of NCEP’s GODAS and CFS to Diagnose and Forecast Coastal Upwelling for California Current Ecosystem Yan Xue, Boyin Huang Climate Prediction Center Janine Fisler University of Maryland at College Park Acknowledgement: Wayne Higgins, Frank Schwing, Wanqui Wang, David Behringer, Arun Kumar

2. Rationale • Coastal upwelling brings nutrients from depth to the surface • Coastal ecosystems flourish in nutrient-rich waters • Monitoring and forecasting upwelling benefits ecosystem and fishery managers www.oceanjsu.com

3. Upwelling in California Current Ecosystem Ekman Pumping ~ wind stress curl Ekman Transport ~ along shore wind stress • North of 36˚N upwelling seasonally • South of 36˚N upwelling year-round • Onset of Upwelling season progresses from March to July along the coast • Both onset date and intensity during upwelling season extremely important Pickett and Paduan, 2003 Huyer, 1983

4. Upwelling Index (UI)(Southwest Fisheries Science Center) 15 Standard Sites • Use NAVY’s FNMOC 3o x 3o and 1ox 1o Sea Level Pressure fields (6-hourly, monthly data since 1967) • Calculate geostrophic winds from SLP • Use along shore wind stress to calculate Ekman transport • SWFSC’s UI is the only routine upwelling product (500 references)

5. Global Ocean Data Assimilation System (GODAS) Background: • Assimilates temperature profiles, synthetic salinity, altimetry into GFDL Modular Ocean Model v.3 • Provides oceanic initial conditions for Climate Forecast System (CFS) • 75˚S to 65˚N with resolution of 1˚ by 1˚ • 40 vertical levels, with 10m resolution in the upper 200m • Pentad temporal resolution • Forced by atmospheric Reanalysis 2 (R2) fields Advantages: • Ability to monitor ocean in near-real time (7 day lag) • Can use marine fields instead of winds to approximate upwelling, e.g. vertical velocity at 50-meter depth • Coupled with CFS: potential for prediction

6. SWFSC vs. GODAS UI: Climatology 60oN large disagreement 57oN – 39oN good agreement South of 39oN large disagreement Baja

7. SWFSC vs. GODAS UI: Anomaly Correlation • Compare both monthly and pentad upwelling • Climatology: 1982-2004 for both data sets • High correlation between 36oN - 57oN • Low correlation north of 57oN and south of 36oN

8. Which index is more accurate? Problem: • Few in situ observations to validate indices • Difficult to make in situ observations Approach: • Derive upwelling index using NCEP surface wind analyses (R1, R2, GDAS) similar to SWFSC index • Verify GODAS and SWFSC, NCEP wind-derived indices against with that derived from QuikScat winds, See Poster P1.3 “Multiple Coastal Upwelling Indices for the Western Coast of North America” by Boyin Huang, Yan Xue and Frank Schwing

9. Cumulative Upwelling Index: CUI • Following Schwing et al., 2006 • Calculate pentad date of climatological onset of upwelling season, “start date” (SD) • Calculate pentad date of maximum climatological upwelling, “maximum date” (MD) • Annually integrate upwelling index from SD to MD • Describe both total and anomalous upwelling Schwing et al., 2006

10. CUI 2005: Delayed Upwelling GODAS SWFSC GODAS SWFSC 48N 39N 45N 36N 42N 33N

11. 2002 Strong Upwelling 2005 Weak Upwelling SST Phytoplankton (from David Foley, NOAA NESDIS)

12. CUI 2006: Healthy Upwelling GODAS SWFSC GODAS SWFSC 48N 39N 45N 36N 42N 33N

13. Standardized CUI Anomaly • CUIA shifted from below- to above- normal in 1998 coincident with PDO shift • Below-normal years: 88, 93, 97, 05 • Above-normal years: 99, 01, 02, 03, 06 • Poor agreement before 1985 • Below-normal years tend to have positive PDO and NINI3.4 97 05 88 93

14. Composites for Below-Normal YearsAMJ (1988, 1993, 1997, 2005) W at 50 m depth • Positive PDO and warm NINO4 SST • Anomalous low SLP in NP • Cyclonic surface wind anom. consistent with SLP • Upwelling dipole at 40N-45N

15. Temp at Depths W at Depths • Warm SST anom. above 50-meter depth • Upwelling reaches 300-meter depth at least • 48N: • Upwelling extends 3o offshore • 42N-45N: • Upwelling confined within 0.5o of the coast Depth

16. CFS Forecast Target AMJ 0 Month Lead April 1 I.C. 5 members

17. CFS Forecast Target AMJ 1 Month Lead March 1 I.C. 5 members 1 month lead is not as skillful as 0 month lead

18. Collaboration between NCEP and SWFSCthrough CTB Proposal • Use high-resolution CFSRR winds and other NCEP reanalysis winds to improve the accuracy of estimations of coastal upwelling • Determine skill of CFS to forecast variations in coastal upwelling • Develop a biologically effective upwelling and transport index (BEUTI) using winds and upper-ocean density structure • Determine model deficiencies and model requirements for coastal applications • Real time monitoring and forecasting products of coastal upwelling

19. Backup Slides

20. 0 Month Lead, AMJ April 1 Initial Condition 5 members

21. Critical Factors Controlling Primary Productivity and Ecosystem Health Giant Kelp • Timing, intensity, and duration of Upwelling • Stratification of water column • Surface water temperature • Turbulence • Freshwater input/salinity • Position of Jet Stream • Light availability, etc. www.abc.net.au

22. Annual Normalized CUI Anomaly: 1983 CUIA

23. Annual Normalized CUI Anomaly: 1986 CUIA

24. Annual Normalized CUI Anomaly: 1988 CUIA

25. Annual Normalized CUI Anomaly: 1993 CUIA

26. Annual Normalized CUI Anomaly: 1997 CUIA

27. Annual Normalized CUI Anomaly: 2005 CUIA

28. Annual Normalized CUI Anomaly: Disagreements