NOAA Climate Obs 4th Annual ReviewNOAA Climate Obs 4th Annual Review

Silver Spring, MD May 10-12, 2006Silver Spring, MD May 10-12, 20061 NOAA’s National Climatic Data CenterNOAA’s National Climatic Data Center

1. SSTs for 20052. Daily SST OI

NOAA’s National Climatic Data CenterAsheville, NC

OAA Climate Observation Program 4th Annual System ReviewSilver Spring, Maryland | May 10-12, 2006

Richard W. Reynolds (NOAA, NCDC)

Top: 2004 Anomaly

Bottom: 2005 Anomaly

Base Period: 1971-2000

• Differences– Slight change in weak

ENSO

– Shift in Tropical North Atlantic positive anomalies

• Similarities– Northern high latitude

positive anomalies ~ 60°N

SST Anomalies

2

Period: Jan '97 - Apr '06

• 1997-98 El Niño

– Peak Jan 1998

• Strong northern high latitude positive SST anomalies in Boreal Summers: '03 - '05

– Peak anomaly similar to ENSO but surface area smaller

– '05 less intense than '03 and '04

• Persistent modest northern middle latitude positive SST anomalies for record

Zonal SST Anomalies

3

NOTE:

Tim

e

Period: Jan '82 - Apr '06

• 1982-83, 1987-88, 1997-98,

major El Niño events

• Northern high latitude positive SST anomalies

– not evident before ~ 1997

• Persistent northern middle latitude positive SST anomalies

– not evident before ~ 1998

• Clear evidence of warming trend with time between 20°S and 80°N

Zonal SST Anomalies

4

NOTE:

Tim

e

Left: July - Sept '04

Right: July - Sept '05

Anomalies shaded

Isotherms: 26-28ºC

• SSTs needed for hurricane formation: roughly > 26.5ºC

• Areas above 28ºC larger in 2005 than 2004

– Warmer anomalies tend to lie in these areas in 2005

Monthly SST

5

NOTE:

NOAA Climate Obs 4th Annual ReviewNOAA Climate Obs 4th Annual Review

Silver Spring, MD May 10-12, 2006Silver Spring, MD May 10-12, 20066 NOAA’s National Climatic Data CenterNOAA’s National Climatic Data Center

2. Daily SST OI

NOAA’s National Climatic Data CenterAsheville, NC

OAA Climate Observation Program 4th Annual System ReviewSilver Spring, Maryland | May 10-12, 2006

Richard W. Reynolds (NOAA, NCDC)Thomas M. Smith (NOAA, NCDC)Kenneth S. Casey (NOAA, NODC)

Dudley Chelton (Oregon State University)

Top: AVHRR Pathfinder Bottom: AMSR-E

For AVHRR:• Absolute latitudes > 40° have

roughly only 5 days of data

• Number of days increases toward the tropics

• Drop offs due to cloud cover

For AMSR:• Absolute latitudes > 40° have

more than 20 days of data

• Drop offs due to precipitation in ITCZ and SPCZ

Jan '03: Number of Days with Nighttime Obs

on 0.25° grid

7

NOAA Climate Obs 4th Annual ReviewNOAA Climate Obs 4th Annual Review

Silver Spring, MD May 10-12, 2006Silver Spring, MD May 10-12, 20068 NOAA’s National Climatic Data CenterNOAA’s National Climatic Data Center

Magnitude of Gradient:Gulf Stream

• Daily OI using AMSR-E for January - March 2003

• Gradients have a stationary part due to topography– Thus, limited

AVHRR data are useful

NOAA Climate Obs 4th Annual ReviewNOAA Climate Obs 4th Annual Review

Silver Spring, MD May 10-12, 2006Silver Spring, MD May 10-12, 20069 NOAA’s National Climatic Data CenterNOAA’s National Climatic Data Center

OI SST Analysis

Weekly (OI.v2)• Grid: 1o • Data: Satellite plus in

situ (ship and buoy) data– Satellite data

• Infrared AVHRR

– 7-Day large-scale satellite bias correction for each satellite

• Spatial error correlation: ~ 700 km

Daily• Grid: 0.25o • Data: Satellite plus in

situ (ship and buoy) data– Satellite data to include

• Infrared AVHRR

• Microwave AMSR-E

– 7-Day large-scale satellite bias correction for each satellite

• Spatial error correlation: ~ 100 km

• AMSR-E has stronger standard deviations than Pathfinder

– Especially in mid-latitude winter

– Clouds reduce Pathfinder sampling

• These differences plus gradient differences suggest that separate Pathfinder OI and Pathfinder + AMSR OI needed

Jan 2003: Standard Deviation

Top: Pathfinder

Bottom: AMSR-E

10

NOAA Climate Obs 4th Annual ReviewNOAA Climate Obs 4th Annual Review

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Pathfinder Advantages: Lower bias variability; data delayed

Operational Advantages: Real-time data; 1981-84 data

Nighttime Zonal Bias: AVHRR - In Situ

AVHRRPathfinder

- In Situ

AVHRROperational

- In Situ

90N

90S

90S

90N'82 '05

NOAA Climate Obs 4th Annual ReviewNOAA Climate Obs 4th Annual Review

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Weekly & Daily OIDecember 1991

12

• Both OIs have bias correction for AVHRR data

• Daily OI uses Pathfinder• Weekly OI uses Operational

From the figure note:• Operational data problem along

35oS– Delayed mode processing allows

data correction

• Daily scales reduced in high gradient areas

NOAA Climate Obs 4th Annual ReviewNOAA Climate Obs 4th Annual Review

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• Both OIs have bias correction for AVHRR data

• Daily OI uses Pathfinder• Weekly OI uses Operational

From the figure note:

• Pathfinder problem near equator in Eastern Pacific

– Zonal bias in Pathfinder worse than Operational

– Number of AVHRR retrievals lower than normal due to ENSO cloud cover

Weekly & Daily OIJanuary 1998

13

NOAA Climate Obs 4th Annual ReviewNOAA Climate Obs 4th Annual Review

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OI Anomalies with Bias CorrectionJanuary 1988: Along equator

From the figure note:

• Operational AVHRR did not have strong biases in this region

• Negative biases in daily OI except at TAO mooring sites near: 155oW, 140oW & 125oW

• OI bias correction fails to correct AVHRR Pathfinder satellite biases

NOAA Climate Obs 4th Annual ReviewNOAA Climate Obs 4th Annual Review

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OI Anomalies with Bias CorrectionJanuary 1988: Along equator

Daily OI computed with EOT bias correction

From the figure note:• Operational AVHRR did

not have strong biases in this region

• Negative biases in daily OI except at TAO mooring sites near: 155oW, 140oW & 125oW

• OI bias correction fails to correct AVHRR Pathfinder satellite biases

• Empirical Orthogonal Teleconnections (EOT) bias correction better at correcting biases

NOAA Climate Obs 4th Annual ReviewNOAA Climate Obs 4th Annual Review

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Daily Bias Differences: 1 Jan '03 - 31 Dec '04

EOTs reduce biases; Some residuals remain

NOAA Climate Obs 4th Annual ReviewNOAA Climate Obs 4th Annual Review

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Daily OI: Ship Biases• Satellite Biases are corrected with respect to

in situ data (ships & buoys)• Ships have larger random and bias

errors than buoys– Ship observations using buckets tend to

be biased cold due to evaporation– Ship observations using engine intake tend

to be biased warm due to engine room heating– Ship metadata needs improvement

• Try to correct ship bias using buoy data– Preliminary tests indicate EOT procedures over a

45-60 day time period would work

NOAA Climate Obs 4th Annual ReviewNOAA Climate Obs 4th Annual Review

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Ship-Buoy SST Zonal Biases

• EOT monthly ship & buoy analyses

• Buoy SST obs increase with time– Significant buoy obs

1994 to present

• Care required to first correct in situ biases than satellite biases

• Easier to correct buoys with respect to ships than inverse

• NOT IMPLEMENTED !!

Annual Ship - Buoy Bias

Tim

e

'94

'05

60°S 60°N

NOAA Climate Obs 4th Annual ReviewNOAA Climate Obs 4th Annual Review

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Daily OI: Status

• Daily OI analysis computed on 0.25° grid with and without satellite EOT bias correction

– Using Pathfinder AVHRR from 4 Jan 1985 to 31 December 2005

– Using Operational AVHRR from 1 Jan 2006 to present– Using AMSR-E from 1 Jun 2002 to 31 Dec 2005– Using Pathfinder AVHRR & AMSR-E from 1 Jun 2002 to

31 Dec 2005• Future Plans

– Add error estimate field to OI – Improve sea ice concentrations and generation of SSTs

from sea ice – Put output files in NetCDF– Make OI operational

• 27 August: Katrina– Weak anomaly in Gulf in

Path + AMSR-E

• 28 August: Katrina– Strong anomaly in Path +

AMSR-E

• 29 August: Katrina– Strong anomaly in Path +

AMSR-E

– Modest anomaly in Path

Daily OI SST Anomalies

EOT satellite bias correction

20

Left: Pathfinder AVHRR OI Right: Pathfinder AVHRR +

AMSR-E OI

NOAA Climate Obs 4th Annual ReviewNOAA Climate Obs 4th Annual Review

Silver Spring, MD May 10-12, 2006Silver Spring, MD May 10-12, 200621 NOAA’s National Climatic Data CenterNOAA’s National Climatic Data Center

Daily FTP OI Products• AVHRR only

– Pathfinder (Jan '85 - Dec '05)– Operational (Jan '06 - present)

Dec '05Jun '02 Present

Pathfinder OperationalAVHRR +AMSR-E

AVHRROnly

Pathfinder Operational

Dec '05Jan '85 Present

• AVHRR + AMSR-E – Pathfinder (Jun '02 - Dec '05)– Operational (Jan '06 - present)– AMSR-E (Jun '02 - present)

• Test other data: TMI, ATSR, MODIS…