# Presentation: 537965

## 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*

## 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

## Upwelling in California Current Ecosystem

- Ekman Transport
-  ~ along shore wind stress

- Pickett and Paduan, 2003

- Huyer, 1983

- Ekman Pumping
- ~ wind stress curl

- 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

## Upwelling Index (UI)(Southwest Fisheries Science Center) 

- 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)

_**15 Standard Sites**_

## 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

## SWFSC vs. GODAS UI: Climatology

- Baja

**60****o****N large disagreement **

**South of 39****o****N large disagreement **

**57****o****N – 39****o****N good agreement **

## 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

- Climatology: 1982-2004 for both data sets
- High correlation between 36oN - 57oN
- Low correlation north of 57oN and south of 36oN

_**SWFSC vs. GODAS UI: Anomaly Correlation**_

## Which index is more accurate?

- Few in situ observations to validate indices
- Difficult to make in situ observations

- _Problem:_

- 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,

- _Approach:_

- See Poster P1.3 “_*Multiple Coastal Upwelling Indices for the Western Coast of North America*_” by Boyin Huang, Yan Xue and Frank Schwing

## 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

## CUI 2005: Delayed Upwelling

_**CUI 2005: Delayed Upwelling**_

**48N**

**45N**

**39N**

**36N**

**33N**

**42N**

**GODAS**

**GODAS**

**SWFSC**

**SWFSC**

## 2002 

*(from David Foley, NOAA NESDIS)*

**2002 **
**Strong Upwelling**

**2005**
** ****Weak Upwelling**

**SST**

**Phytoplankton**

## CUI 2006: Healthy Upwelling

**48N**

**45N**

**42N**

**39N**

**36N**

**33N**

**GODAS**

**SWFSC**

**GODAS**

**SWFSC**

## Standardized CUI Anomaly

_**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**

**88**

**93**

**97**

**05**

## Composites for Below-Normal YearsAMJ (1988, 1993, 1997, 2005)

_**Composites for Below-Normal Years**__**AMJ (1988, 1993, 1997, 2005)**_

**Positive PDO and warm NINO4 SST **
**Anomalous low SLP in NP**
**Cyclonic surface wind anom. consistent with SLP**
**Upwelling dipole at 40N-45N**

**W at 50 m depth**

## Depth

**Depth**

**Temp at Depths**

**W at Depths**

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

## CFS Forecast

**Target AMJ**
**0 Month Lead**
**April 1 I.C.**
**5 members**

**CFS Forecast**

## CFS Forecast

**Target AMJ**
**1 Month Lead**
**March 1 I.C.**
**5 members**

**CFS Forecast**

**1 month lead**
**is not as skillful as 0 month lead**

## Collaboration between NCEP and SWFSCthrough 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

## Backup Slides

## 0 Month Lead, AMJ

**0 Month Lead, AMJ**
**April 1 Initial Condition**
**5 members**

## Critical Factors Controlling Primary Productivity and Ecosystem Health 

- _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

- Giant Kelp

## Annual Normalized CUI Anomaly: 1983 CUIA

## Annual Normalized CUI Anomaly: 1986 CUIA

## Annual Normalized CUI Anomaly: 1988 CUIA

## Annual Normalized CUI Anomaly: 1993 CUIA

## Annual Normalized CUI Anomaly: 1997 CUIA

## Annual Normalized CUI Anomaly: 2005 CUIA

## Annual Normalized CUI Anomaly: Disagreements