Evaluation of the MISST SST satellite product as a potential

observational dataset for HYCOM hindcast

SLT TOURNIER Emmanuel (visitor)

Eric CHASSIGNET

OUTLINE

• Motivation• Model:

– HYCOM (HYbrid Coordinate Ocean Model)

• Datasets:– MISST (Multi-sensor Improved Sea Surface

Temperature)

– NDBC (National Data Buoy Center)

• Results• Discussion and conclusion

• Aim of my study :– To know if the new SST satellite product

MISST could improve HYCOM, if HYCOM assimilated it.

• Why?– MISST is new dataset and HYCOM assimilate

older satellite data

Method

To compare HYCOM outputs and MISST dataset using independent data (NDBC buoys data)

The study is a statistical one, leads over one year for several locations

HYCOM

• Global ocean model, 1/12° horizontal resolution

• Currently, HYCOM assimilates the SST dataset from the satellite AVH-RR (Infra-red, resolution 9 km) through NCODA

(HYbrid Coordinate Ocean Model)

MISST

• New project with 2 main objectives :

– to produce an improved, high-resolution, global, NRT SST analysis using IR and MW satellites.

– to demonstrate the impact of these improved SSTs on operational ocean models, numerical weather prediction, and tropical cyclone intensity forecasting.

(Multi-sensor Improved Sea Surface Temperature)

MISST data

From website : “http://misst.org”

NDBC

- SST measured at the depth of 1m, every hour

- Latitude and longitude given

(National Data Buoy Center)

From website : “http://www.ndbc.noaa.gov/”

SST time series for year 2006 at location buoy # 42003

HYCOM

MISST

NDBC

ANalysis Of VAriance (ANOVA)

Buoy # 42001 Buoy # 42003

Trend :

For each season, HYCOM mean better matches with NDBC mean than MISST

In some cases, MISST mean is significantly different from NDBC

Linear regression for residual

The residual is the SST difference between each day and the average over the week.

Relationship :

HYCOM has a better slope, but not always.

Buoy # 42001

Buoy # 42003

SST difference

buoy # 42002

buoy # 42001

Conclusion & discussion

• No major difference between HYCOM outputs and MISST data

• Seasonal mean SST from HYCOM is closer to the NDBC data

• MISST data tend to have negative bias compared to the NDBC data

• Comparison directly between AVH-RR and MISST could be interesting

• Compare HYCOM with others MISST products when available