Geospatial Interpolation of Remotely Sensed Observations in

the Chesapeake Bay: an Ecological Forecasting Application

Erin Urquhart1, Rebecca Murphy1,Matt Hoffman2, Ben Zaitchik1, 1Johns Hopkins University, 2Rochester Institute of Technology

Vibrio in the Chesapeake Bay

* V. cholerae * V. vulnificus * V. parahaemolyticus

Urquhart et al. AGU Fall Meeting 2012December 3, 2012 Satellite Ocean and Coastal Applications- Current and Future II

z(V.c)= -1.1939 + (0.1233 * Temp) – (0.1997 * Saln) – (0.0324 * (Temp * Saln)

Remote Sensing of Vibrio in the Chesapeake Bay

Urquhart et al. AGU Fall Meeting 2012December 3, 2012 Satellite Ocean and Coastal Applications- Current and Future II

Urquhart et al., (2012) RSE

Percent Satellite Coverage by Month

Urquhart et al. AGU Fall Meeting 2012December 3, 2012 Satellite Ocean and Coastal Applications- Current and Future II

Urquhart et al. AGU Fall Meeting 2012December 3, 2012 Satellite Ocean and Coastal Applications- Current and Future II

Geostatistical Spatial Interpolation: Kriging• What is Kriging?

• Determine data dependency

• Semivariogram

– Spatial autocorrelation

– Model fitting

• Predictions

• Ordinary Kriging– Y(s) = β0 + ε(s)

– Constant mean is unknown

• Universal Kriging– Y(s) = β0 +β1X1(s) + … + βpXp(s) + ε(s)

– Trend in the data

Urquhart et al. AGU Fall Meeting 2012December 3, 2012 Satellite Ocean and Coastal Applications- Current and Future II

Urquhart et al. AGU Fall Meeting 2012December 3, 2012 Satellite Ocean and Coastal Applications- Current and Future II

Urquhart et al. AGU Fall Meeting 2012December 3, 2012 Satellite Ocean and Coastal Applications- Current and Future II

Urquhart et al. AGU Fall Meeting 2012December 3, 2012 Satellite Ocean and Coastal Applications- Current and Future II

EOF Analysis

Parameter Method 1st Mode (%) 2nd Mode (%) Total (%)

Salinity OKUK

OKUK

Temperature

7969

8093

1321

145

9290

9498

Urquhart et al. AGU Fall Meeting 2012December 3, 2012 Satellite Ocean and Coastal Applications- Current and Future II

Comparison of Interpolated and ChesROMS Parameter Output

Parameter Method ME MAE RMSE

Salinity UKROMS

UKROMS

Temperature

0.61-0.52

0.28-0.76

0.94

0.990.98

R2

(psu)

(oC)

1.891.46

0.63-1.14

2.471.86

0.84-1.39

0.86

Urquhart et al. AGU Fall Meeting 2012December 3, 2012 Satellite Ocean and Coastal Applications- Current and Future II

Xu et al. (2002)

SO WHAT?

• Methods had similar SSS errors during data heavy months

• Interpolated SST had a smaller average error than ChesROMS

• Interpolated observations act as a second-source of Bay-wide observations

• Extreme event accuracy

• Data assimilation potential (future work)• Observations can be utilized when they are available/reliable• Hoffman et al. (2012)

• Two techniques offer complementary information that can be applied to Vibrio spp. monitoring

Urquhart et al. AGU Fall Meeting 2012December 3, 2012 Satellite Ocean and Coastal Applications- Current and Future II

z(V.c)= -1.1939 + (0.1233 * Temp) – (0.1997 * Saln) – (0.0324 * (Temp * Saln)

Remote Sensing of Vibrio in the Chesapeake Bay

Urquhart et al. AGU Fall Meeting 2012December 3, 2012 Satellite Ocean and Coastal Applications- Current and Future II

Remote Sensing of Vibrio in the Chesapeake Bay

Urquhart et al. AGU Fall Meeting 2012December 3, 2012 Satellite Ocean and Coastal Applications- Current and Future II

Acknowledgments

Johns Hopkins Applied Physics Lab, Carlos del Castillo

Johns Hopkins University, Rebecca Murphy

Cornell University, Dr. Bruce Monger

University of Delaware, Erick Geiger

University of Maryland, Bradd Haley, Elisa Taviani

NASA Goddard, Molly Brown, Vanessa Escobar

Funding Sources

Johns Hopkins University