Wednesday, May 25, 2011

Tropical Pacific Weather

The U. of Hawaii Meteorology department offers a great compendium of tropical weather resources. Plus they couple all this cutting edge numerical modeling and satellite technology with the ability to build animated gifs...

Click to activate some old school animated gif action

Available here:
http://weather.hawaii.edu/

Monday, April 11, 2011

In search of unfair competitive advantage (aka Puget Sound current models)

After extensive and painstaking research involving repeated instances watching our fleet walk away from us by taking advantage of the vagaries of Puget Sound tidal currents, we decided that these currents are perhaps indeed worth paying attention to. 

One could of course go down to the local chandlery and buy a copy of an established and well-vetted current atlas that would be both inexpensive and easily used onboard. That however has the disadvantage of requiring leaving the office desk and being entirely too practical. 

Instead, we'll turn to the MoSSEA (Modeling the Salish Sea) research work being done at the University of Washington. This hindcasting effort uses the Regional Ocean Modeling System (ROMS) with atmospheric, river, and tidal forcing to create high resolution models of the Puget Sound circulation system. 

I am currently making a general pest of myself bugging busy people to give me true current velocity outputs, and if I get these I will probably keep them to myself in search of the aforementioned 'unfair competitive advantage.' However, here are some publicly available toys to take a look at:

While I couldn't find any explicit surface current output available from the MoSSea project, I did find this nice animation of surface salinity over a spring-neap tidal cycle. Mixing significantly complicates the use of salinity as a tracer of currents, but it is still interesting to watch this animation for some of the complex eddies and other features relevant to sailing. Click here for animation.


The other fun toy worth looking at is flowWeaver, a visualization tool built on the same MoSSea model as the animation. This will most likely be available at some point as a web app, but in the meantime you can download it and run it on your local machine. Mousing over the map reveals the deep and surface paths that a water parcel at your chosen location would take over a two week period. Clicking on the map releases a 'particle' for you to track, and clicking and dragging animates a section of the map. Click here for flowWeaver.

Tuesday, March 29, 2011

Tracking COYOTE

Tracking COYOTE in the 2010 Pac Cup and return. Surface level pressure in color, wind vectors in blue, and 500 hPa height in white. Rough boat position shown with circle.

Data from NCEP 4x daily reanalysis.

Full screen is most highly recommended.



The good ship TAO seeks a leper colony.








20 years of trade wind goodness. Assume that your experience will be very unlike what is shown here. Note however the relative stability of the Pacific high moving into the summer, as well as the decrease in overall wind speed.