Meteorology and Data Formats
2015-06-01
Chris Little, UK Met Office
Co-chair OGC Meteorology & Oceanography Domain WG
© Crown copyright Met Office
Contents
This presentation covers the following areas
• Historical Background
• Where we are now
• Some Data Formats
• Questions & Answers
© Crown copyright Met Office
Historical Background
© Crown copyright Met Office
© Crown copyright Met Office
Daily Weather reports
© Crown copyright Met Office
1831 Beaufort Wind Force Scale
0 Calm
1 Light Air
Or just sufficient to give steerage way
2 Light Breeze
Or that in which a man-of-war with all sail set, and
clean full would go in smooth water from.1 to 2 knots
3 Gentle Breeze
3 to 4 knots
4 Moderate Breeze 5 to 6 knots
5 Fresh Breeze
Or that to which a well-conditioned man-of-war could
just carry in chase, full and by. Royals, etc
6 Strong Breeze
Single-reefed topsails and top-gallant sail
7 Moderate Gale
Double reefed topsails, jib, etc
8 Fresh Gale
Treble-reefed topsails etc
9 Strong Gale
Close-reefed topsails and courses
10 Whole Gale
Or that with which she could scarcely bear closereefed main-topsail and reefed fore-sail
11 Storm
Or that which would reduce her to storm staysails
12 Hurricane
Or that which no canvas could withstand
© Crown copyright Met Office
Beaufort Wind Speed Scale: Sea State
Speed km/hr knots
Term
Sea
0 Calm
Calm
Calm
Sea like mirror
1 2-5
1-3
Light Air
Ripples with appearance of scales: no foam
crest
2 6-11
4-6
Light Breeze
Small wavelets; crests of glassy
appearance, not breaking
3 12-18
7-10
Gentle Breeze
Large wavelets; crests begin to break;
scattered whitecaps.
4 19-30
11-16
Moderate Breeze
Small waves, becoming longer; numerous
whitecaps.
5 31-39
17-21
Fresh Breeze
Moderate waves, taking longer form; many
whitecaps; some spray
6 40-50
22-27
Strong Breeze
Larger waves forming; whitecaps
everywhere; more spray.
7 51-61
28-33
Near Gale Sea heaps up; white foam from breaking
waves begins to be blown in streaks.
8 62-74
34-40
Gale
Moderately high waves of greater length;
edges of crests begin to break into
spindrift; foam is blown in well-marked
streaks.
9 75-87
41-47
Strong Gale
High waves; sea begins to roll; dense
streaks of foam; spray may reduce
visibility.
Storm
Very high waves with overhanging crests;
sea takes white appearance as foam is
blown in very dense streaks; rolling is
heavy and visibility is reduced
Violent Storm
Exceptionally high waves; sea covered with
white foam patches; visibility further
10 88-102 48-55
103-117
© Crown copyright Met11
Office
56-63
Beaufort Wind Speed Scale: Land
Code km/hr knots
Term
0 Calm
Calm
Calm
Smoke rises vertically.
1 2-5
1-3
Light Air
Smoke drifts slowly downwind.
2 6-11
4-6
Light Breeze
Leaves rustle.
3 12-18
7-10
Gentle Breeze
Leaves are in motion.
4 19-30
11-16
Moderate Breeze
Small branches on trees move.
5 31-39
17-21
Fresh Breeze
Small trees sway.
6 40-50
22-27
Strong Breeze
Large branches sway.
7 51-61
28-33
Near Gale Whole trees in motion.
8 62-74
34-40
Gale
Twigs and small branches break off
trees.
9 75-87
41-47
Strong Gale
Large branches break off trees;
slight structural damage.
10 88-102
48-55
Storm
Trees broken; minor structural
damage.
11 103-117 56-63
Violent Storm
Widespread damage.
12 108-132 64-71
Hurricane
Violent movement of trees and much
destruction.
13 133-148 72-80
14 149-165 81-89
15 166-183 90-99
16 184-200 100-108
© Crown copyright Met Office
17 201+109+
Land
Beaufort’s Weather Code
1820-1825 version
b. Blue sky
c. Clear, transparent atmosphere
ci. Cirrus clouds
cl. Cloudy
cu.Cumulus clouds
d. Mist (damp air)
Dk Dark weather but atmosphere clear
f. Foggy
f: Dense Fog
g. Gloomy weather
h. Haze
© Crown copyright Met Office
Establishment of Met. Services
• Standardised instruments/processes (Science)
• Standardised collection (marine “best practice”)
• Transmission (optical telegraph, then electrical)
• Collation (Institution)
• Analyse and Forecast (manual, graphical, numerical)
• Products (Institution)
• Dissemination
• Broadcast (newspapers, using rotary lithography)
• Point to point (willing to pay!)
• Quality control (Science, stakeholders)
• Already International, no underlying theory
© Crown copyright Met Office
© Crown copyright Met Office
© Crown copyright Met Office
The Primitive Equations of
Meteorology – p, T, (u, v) and q
Ideal Gas Law (Equation of State)
First Law of Thermodynamics
Hydrostatic Law
Newton’s Second Law of Motion
Conservation of Mass Applied to the
Atmosphere (Equation of Continuity )
© Crown copyright Met Office
© Crown copyright Met Office
© Crown copyright Met Office
Operational NWP in 2013
Global
16km 70 level
 initialised by Hybrid 4DVAR (40km)
 6 day forecast 2x/day (plus 3 day
forecast 2x/day at intermediate times)
33km ensemble with 12 (36) members;
3 day forecast, 4x/day
60km coupled seasonal (7 months)
forecast with 4 members/day
Regional
UK 1.5km 70 level, 36 hour forecast
8*day
UK 2.2km, ensemble with 12 members,
36 hour forecast, 4x/day
Europe 4km, 5 day forecast, 2x/day
Plus many others for Defence or
Commercial Customers
Coordinate system: linear
combination of height and pressure
© Crown copyright Met Office
Where we are now
(big data will get bigger)
© Crown copyright Met Office
Quantifying uncertainty with
ensembles
Deterministic Forecast
Forecast
uncertainty
Initial Condition
Uncertainty
X
CHAOS
Analysis
Climatology
time
© Crown copyright Met Office
© Crown copyright Met Office
Ensemble of many forecasts
© Crown copyright Met Office
Some Data Formats
© Crown copyright Met Office
WMO Data Formats
SYNOP: Standard meteorological hourly surface weather reports
SMUK01 EGRR AAXX 08214 03148 46/// /0507 11034 21039 92050=
AAXX 08214 03204 42575 72425 10055 20006 39918 49937 58006 878// 92050 333 55300 20140
82822 85631 87642 91038 90710 91138=
SIGMET: Aviation ad hoc significant weather report
WSBY31 UMMS 090205
UMMV SIGMET 1 VALID 090200/090600 UMMS-UMMV MINSK FIR SEV ICE (FZRA) FCST E OF
E026 BLW FL100 MOV NE 30KMH NC=
METAR: Aviation standard half hourly weather reports
EGBB 091320Z 25011KT CAVOK 06/01 Q1011=
EGCC 091320Z 26012KT 9999 FEW022 06/01 Q1010 NOSIG=
TAF: Aviation Terminal Aerodrome Forecast
ESKN 091130Z 0912/1012 21007KT 9999 SCT020 PROB30 0922/1005 BKN012 BECMG 1007/1009
24016G26KT=
ESMS 091130Z 0912/1012 20010KT 1200 BR BKN002 PROB40 0913/1012 9999 BKN016=
ESSA 091210Z 0912/1012 20010KT 9999 FEW012 BKN025 TEMPO 0912/0915 BKN012 PROB40
0922/1006 BKN008 BECMG 1001/1003 20017G28KT=
CREX: modernised, table-driven data format
KULC02 RJTD 070244
CREX++
T000101 A008 D07043++
47 646 TATENO 3606 14013 00031 2011 01 07 02 44 003 125 00 00 0343 190++
7777
BUFR, GRIB are binary, table driven, formats for massive data volumes, not suitable for
human inspection
© Crown copyright Met Office
WMO binary, table-driven,
formats GRIB, BUFR
© Crown copyright Met Office
Meteorological data structures
• Data at points on the surface
• Data time series for a given fixed surface location
• Data along trajectories (sequences of locations
and times):
• Horizontal 2D
• Vertical 2D
• 3D
• Grids:
• 2,3,4,5,… D
• Various combinations of (x,y), z, t
• No polygons!
© Crown copyright Met Office
BUFR Binary Universal Format
for data Representation
• Points, time series and trajectories
• Can do grids, but not very effective
• Table Driven:
• Table Versions - do not require software changes
• Format Edition –need software changes
• Values can be:
• Quantities, expressed as scaled positive integers
• enumerated types, managed registries
• bit flags
• sequential structure
• 16 bit orientated
• CSV like structure
© Crown copyright Met Office
BUFR Structure
1. Header , summary metadata inc BBox
2. Data Descriptors (must include x,y,z,t)
3. Dave Values
4. File End Marker
•
d1
•
v11 v12 v13 v14 v15 …
•
v21 v22 v23 v24 v25 …
•
v31 v32 v33 v34 v35 …
•
….
© Crown copyright Met Office
d2
d3
d4 d5 …
Data Descriptors
• 16 bit integer/pattern FXY (2/6/8)
• Table B parameters, 16K possible parameters
•
•
•
•
•
64 categories of 256 for human convenience
Name
UoM
Reference value
Scale factor
• Table D sequences, 16K possible definitions
• simple,
• deeply nested
• structured
• Replication counts for descriptors/values
• Table C operators, on both descriptors or values
© Crown copyright Met Office
BUFR Lessons Learnt
• Coordinate descriptors (x,y,z,t) should not be ‘modal’
• Too many complicated operators or qualifiers added for
quality control and specific users
• API not defined
• Character encoded version not completely compatible
• Not re-factored15 years ago. E.g. nesting rules inconsistent
• Very compact
• Flexible – tables excellent. Local use space too generous
• Ahead of its time
© Crown copyright Met Office
Questions and answers
© Crown copyright Met Office
History of inventing/tailoring
technologies
☒ Operating Systems
☒ Programming Languages
☒ Telecoms Protocols
☒ Telecom computers (message switching)
? Data Formats
☑ Semantics
☑ Visualisations
Technology Trends
• NWP resolutions from 500km -> 1km -> 0.3km -> ?
• More blending of our data with customers/users:
• Met, Ocean, Hydro, Space, Ecology, Earth Systems
• Likely evolution / interactions
• WMO Formats -> general Scientific Formats (netCDF,..)
•
-> Geospatial standards ?
• Visualisations -> general graphics technologies (SVG, …)
•
-> Geospatial standards (SLD/SE?)
WOW Weather Obs Website
• http://wow.metoffice.gov.uk/ Beta
• June 2011 – 16 August 2012
• 51,029,844 (non-WMO) weather observations
• 2152 registered sites
• 345,978 web site visits
• 156 different countries
Descargar

Title XXXXXXXX - Open Geospatial Consortium