x
3.5.1
The collectionltransmission system ......................................... 47
3.5.2
The data collection procedures and quality control on board .. 49
3.5.3
Data quality control .................................................................. 50
3.5.4
Near real time data flow ........................................................... 50
3.6
Discussion and conclusions ...................................................... 50
4
A Generalization of a Sigma Coordinate Ocean Model and an
Intercomparison of Model Vertical Grids ............................ 55
GEORGE L. MELLOR, SIRPA M. HĂKKINEN, TAL EZER AND
RICHARD C. PATCHEN
4.1
Introduction .............................................................................. 55
4.2
The Goveming Equations ........................................................ 56
4.3
Transformation to the s-coordinate system .............................. 57
4.4
Finite Difference Equations ..................................................... 60
4.5
Model Strategy ......................................................................... 61
4.6
Numerical Simulations Comparing Three Vertical Coordinate
Systems .................................................................................... 61
4.7
Errors ........................................................................................ 68
4.8
Other Grids ............................................................................... 71
4.9
Summary .................................................................................. 71
5
Atmospheric Data Assimilation and Quality Control ......... 73
ANDREW C. LORENC
5.1
Introduction .............................................................................. 73
5.2
What is Data Assimilation? ...................................................... 73
5.3
Useful prior knowledge about the atmosphere ......................... 74
5.4
Products and Uses of Assimilation .......................................... 75
5.5
The Optimal Combination ofInformation ............................... 75
5.5.1
Bayes' Theorem for Discrete Events ........................................ 75
5.5.2
Single-variable Bayesian Analysis with Gaussian probability
distribution functions ................................................................... 76
5.5.3
One-dimensional Bayesian Analysis ........................................ 78
5.5.4
Practical Analysis Methods ...................................................... 83
5.6
Quality Control ......................................................................... 84
5.6.1
Why Quality Control? .............................................................. 84
5.6.2
Discrete Bayes TheoremApplied to Gross Observational Errors 85
5.6.3
Non-Gaussian Model for Observational Errors ....................... 85
5.6.4
Analysis, allowing for gross errors .......................................... 86
5.6.5
What is the Best Analysis? ....................................................... 87
5.7
Practical Methods of Quality Control ...................................... 89