Wednesday, November 17, 2004

How to get OpenDAP working for ROMS model output

Rich Signell sent me this advice on getting DODS/OpenDAP working for my model output:


The 5 step program to a blissful OpenDAP Life

Tuesday, November 16, 2004

Office of Coast Survey - Historical Maps and Charts

A huge array of historical charts are available online:

Office of Coast Survey - Historical Maps and Charts

They use a goofy format, called MrSid, that must be decoded into something more sensible to use. I use the linux decoder created by Lizardtech found here. Once you decompress the image, you see why they use this format which compresses the image using wavelets.

Below is an image of a historical chart of the Mississippi River Delta first published in 1874 found by searching for key word 'Mississippi'. Click the image for a higher resolution image (still only 1/4 of full resolution).

Tuesday, November 9, 2004

TGLO skill estimates

Skill estimates for the mooring locations were calculated from a simulation lasting one year: summer 2001 to summer 2002. The largest skill is for buoy D, away from the Mississippi, and near the coast. Most of the skill estimates are around, or beneath zero, indicating that the model error is of a similar magnitude to the variance. The first two columns of numbers are the skill for the east-west and north-south velocities. The third column is the skill for speed. This particular model run had no buoyancy forcing, and represents the 'base' model skill, to which future, improved runs will be compared.

All timeseries use the mean of the data for the 'climatology', which produces the lowest skill estimates (see paper on skill linked below). Also, if the timeseries are filtered more, say with a 3-day boxcar, the skill is increased so that 4 to 5 of the skill estimates are positive.

B : -1.3335 : -0.3682 :-1.4042
D : -0.5348 : 0.2566 :-0.2602
F : -1.2726 : -2.9699 : -2.0598
J : -4.2723 : -0.9684 : -3.1124
K : -0.5815 : -1.4996 : -1.5841
N : -2.9575 : -1.5863 : -0.5991
R : -0.0772 : -0.5407 : -0.3376
S : -2.9290 : -1.9349 : -9.9881
V : -3.6531 : -5.8301 : -0.9598
W : -0.4621 : -0.3207 : -0.3583

Wednesday, November 3, 2004

Skill paper.

I just submitted this paper to Ocean Modelling. The paper discusses estimating model skill when the primary feature is a descrete event.

yugop.com

This guy makes some very interesting animations.