Evolving threedimensional structures in atmospheric flow: visualisation and communication'

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Evolving three-dimensional structures in
atmospheric flow visualisation and communication.

• Ian N. James
• Dept of Meteorology, University of Reading
• (formerly Chair of Publishing Committee, Royal
  Meteorological Society)

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Remember the 1960s?
The medium is the message
.or the graphic is the science!
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Theme of talk

• Geophysical fluid dynamics is the study of four
  dimensional structures
• Traditionally had to represent them on two
  dimensional sheets of paper
• Science is not done until it has been
  communicated!

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The nature of meteorology.
..500 giga-numbers to this!
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Visualizing 4D into 2D

• Cross sections in different directions through
  (x,y,p,t) space
• Use of means and variances, filters to isolate
  particular features

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Forecasts from 21/1/03
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Vertical structure
Flow at different levels in the atmosphere
simultaneously. (22/1/87)
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Storm tracks

• Organisation of midlatitude weather systems, with
  local maxima of intensity
• Relationship to mean flow
• Implications for large scale forcing of the
  atmosphere - feedback
• Example of how limitations of visualisation have
  impacted on conceptual models.

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Storm tracks the Eulerian view
All based on 2-6 day filtered transients for DJF
EKE, 25 kPa
Upward temperature flux, 70 kPa
Momentum flux, 25 kPa
Height variance, 25 kPa
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Stormtrack lifecycle theory
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Eady growth rate traditional journal picture
Growth rate of most unstable Eady mode at 70
kPa (Hoskins Valdes 1990)
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Eady growth rate(DJF)
Growth rate of most unstable mode
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Eady growth rate some different perspectives
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Longitude-height section (DJF NH)
EKE
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A 3D view of the NH winter storm track

• EKE
• Vertical temp flux
• Poleward wind for a single season.
• Orography

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Hovmöller plot - DJF

• v at 30 kPa, 34-66N
• High pass filtered
• (2 6 day filter)

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v during 84/85 winter
Eurasia
N America
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Communicating 4D vision

• Most paper journals still prefer monochrome line
  drawings.
• Greyscale unreliable and expensive
• Colour very expensive - only economical for huge
  print runs (10,000 upwards)
• Movies impossible

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Electronic publishing

• Pros
• Unrestricted use of colour, movie loops, etc..
• Rapid publication (non-quantized)
• Links to web sites
• Important that the highest standards of
  refereeing apply.

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Electronic publishing

• Cons
• Authentication of material (what do referees
  see?)
• Use of visual formats in practise restricted
• Publication in fact little faster than paper
  journals (hold-ups from refereeing, publishers
  bureaucracy)
• Financial model how is publication to be paid
  for? (Readers? Authors? Sponsors?)

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Conclusions

• Unrestricted use of colour, 3D plotting, colour
  enables us to approach 4D visualization of GFD
  objects
• Liberates hypothesis-setting
• We are getting used to increasingly sophisticated
  packages on our desktops.
• Publication is still a real block to
  communication.
• Need a Powerpoint-like e-publishing package!