GIS Tools for Accessing Arctic Bathymetry: International Bathymetric Chart of the Arctic Ocean (IBCAO)Martin JakobssonCenter for Coastal and Ocean MappingJoint Hydrographic CenterUniversity of New Hampshire

The IBCAO bathymetry modelUsers of IBCAOGIS tools for accessing the IBCAO grid modelFuture IBCAO GIS products (Error estimation of the IBCAO bathymetry, vector contours)

IBCAOGrid model representing Arctic Ocean bathymetry and topography

Grid cell spacing: 2.5 x 2.5 kmProjection: Polar stereographicTrue scale: 75 NDatum: WGS 84

TRACKLINE SOURCES

MAP SOURCES

SOURCES

GRID COMPILATIONData cleaning & mining(MGE)Block median filteringGridding using continuous curvature splines in tension (Smith & Wessel, 1990)Data gathering(MGE)

IBCAO web site:http://www.ngdc.noaa.gov/mgg/bathymetry/arctic/arctic.html

USERS OF THE IBCAO BATHYMETRY GRIDIBCAO web site statistics 2000Oceanography modeling (e.g. Arctic ice-ocean model for the Polar Ice prediction System (PIPS), US Naval Postgraduate School; ARCICE, Southampton Oceanography Centre, UK)Geophysical modelingIce sheet modelingCartographic applications Average download per visitor (kb) visitors per weekIBCAO web site news: February, 26 652 accesses and 99297 hits

Chart7

8582016.3

6311560.6

5581534.2

843619.6

6541243.1

414271.4

709335.2

3741117.9

457629.2

8071471.4

12271766.1

7372709.3

606702

4301187.8

4281433.2

4041760

9581451.4

4391975.3

4991161.6

5902448.1

5532905.2

3772465.7

7502900

6642372.2

6584526.9

6171440.4

7334108.8

9252720.5

9003609.4

9313058.6

13493205.4

16505217.5

11425103.3

5203853.5

7073975.9

23595.5

Accesses (no)

Sheet1

Accesses (no)Average download/visitor (kb)Date

8582016.31-Nov

6311560.625-Oct

5581534.218-Oct

843619.611-Oct

6541243.14-Oct

414271.427-Sep

709335.220-Sep

3741117.913-Sep

457629.26-Sep

8071471.430-Aug

12271766.123-Aug

7372709.316-Aug

6067029-Aug

4301187.82-Aug

4281433.226-Jul

404176019-Jul

9581451.412-Jul

4391975.35-Jul

4991161.628-Jun

5902448.121-Jun

5532905.27-Jun

3772465.77-Jun

750290031-May

6642372.224-May

6584526.917-May

6171440.410-May

7334108.83-May

9252720.526-Apr

9003609.419-Apr

9313058.612-Apr

13493205.45-Apr

16505217.529-Mar

11425103.322-Mar

5203853.515-Mar

7073975.98-Mar

23595.51-Mar

Sheet1

&A

Page &P

Accesses (no)

Sheet2

Sheet3

GIS Tools for accessing the IBCAO modelESRI: ArcView, ArcInfo (Spatial Analyst, Arc Grid)Intergraph: MGE (Terrain Analyst) Geomedia (MFworks from ThinkSpace Inc.)Clarks Labs:Idrisi32Caris:HIPS

Web GIS toolsIntergraph: Geomedia Web MapESRI: ArcIMS3Geophysical and Mapping softwaresIVS: Fledermaus

Public domain: Generic Mapping Tools

Regional grid models representing bathymetry/topography are often used as a base for oceanographic/climate/geophysical/ice sheet modelingThe modeling results are often interpreted without knowledge of the spatial differences in reliability of the underlying bathymetry/topography modelThe idea is to create a grid with the same structure as the bathymetry/topography grid containing an estimate of the standard deviation of the errors of the bathymetry/topographyTHE NESSECITY FOR AN ERROR ESTIMATION

USING THE MONTE CARLO METHOD FOR ERROR ESTIMATIONRandomly vary the source data within constraints determined by meta data (navigation, echo sounder etc)Go through the process with which the bathymetry grid is compiled (block median filtering + continuous curvature splines in tension)1.2.This processes are continued until

STATISTICSsRun 1...Run n

Standard deviation of estimated error (% of block median depth)

IBCAO contours in Geomedia