cosmo overview n - clm-community · short overview of the cosmo model system ... 20 km and 60...

Short overview of the COSMO Model System and Operational Data Flow

Detlev Majewski, DWD, [email protected]

Cosmin Barbu, NMA, [email protected]

Outline:

� COSMO World usage

� COSMO Model� Initial and lateral boundary data

� Forecast run & Post-processing

� Model grid

� File name conventions

� Basics of GRIB1 code

� Analysis and forecast fields available

COSMO World usage

• Until 2012

COSMO World usage

• Beyond 2012

COSMO - Documentation & Training

• More information on COSMO: http://cosmo-model.org/ like COSMO documentation:– Dynamics and Numerics - PART I– Physical Parameterization - PART II– Data Assimilation - PART III– Preprocessing (INT2LM) - PART V– User's Guide - PART VII

• Next training / meeting opportunities (in 2013):– February 18 - 22: COSMO/CLM Training Course, BTZ Langen– March 6 – 8: COSMO/CLM Seminar, DWD, Offenbach– July 17 – 28: Regional NWP Capacity Building, BTZ Langen

General structure of a regional NWP system

GraphicsGraphicsVisualizationVisualization

MOSMOSKalmanKalman

ApplicationsApplicationsWave Wave modelmodel,,TrajectoriesTrajectories

VerificationVerificationDiagnosticsDiagnosticsprovidedprovided forfor COSMO COSMO byby DWDDWD

TopographicalTopographicaldatadata

Initial Initial datadata((analysisanalysis))

Lateral Lateral boundaryboundary datadata

DirectDirect modelmodeloutputoutput (DMO)(DMO)

RegionalRegionalNWPNWPModelModel

Lateral boundary data for COSMO modelbased on GME forecasts, Part I

The global model GME covers the Earth with an icosahedral-hexagonal grid; grid spacing: 20 km and 60 layers .

1.474.562 grid points / layer

Grid cell area of GME: 346 km 2

To cover a given COSMO domain, only a small part of GME grid points is needed.

If the regional domain is 3000 x 3000 km 2, the number of GME grid points is given by 3000 x 3000 / 346 = 26.012 only !

Only these GME grid points are being transferred to the National Met. Service via the Internet for the COSMO model.

Lateral boundary data for COSMO modelbased on GME forecasts, Part II

If the regional domain is 3000 x 3000 km 2, the number of GME grid points is given by 3000 x 3000 / 346 = 26.012 only !

For each GME grid point, the following fields will be transferred from 0 to 72 (or 120 hours) at 3-hourly intervals:8 multi-layer atmospheric fields (= 8 x 60 = 480 fiel ds)3 multi-layer soil fields (= 3 x 8 = 24 fields)12 single-layer fields (= 12 x 1 = 12 fields)Total: 516 2D-fields

If each field has 26.000 grid points (values) and ea ch value is stored in 2 bytes, the total file size is: 27 MByte.

If the file is compressed (bzip2 or gzip), the size is about 19 MByte.

If the GME data for a 72-h forecast (25 x 19 = 475 M Byte) should be transferred within one hour, the sustained bandwidth of the internet link must be about 1 MBit/s .

DWD (Germany) Internet Nat. Met. Service (NMS) NEC SX9 hpc ftp Firewall computer

GME analysis/forecast

gme_newSend only those GME giff00000000.gzgrid points covering gfff00030000.gzthe NMS domain(s). ... (bitmap; compressed) gfff03060000.gz

00 UTC + 78 (120) h; interval 3h; data transmission (via ftp) starts at 02.45 UTC.12 UTC + 78 (120) h; interval 3h; data transmission (via ftp) starts at 14.45 UTC.

GME at the DWD and the COSMO model at the NMS can r un in parallel!

IF NMS intends to use a larger model domain, it wil l need a new bitmap (contact M. Gertz)!

Initial and lateral boundary data based on the global model GME of DWD

Interpolate/adapt GME data to higher-resolution COSMO gri ds

See: http://www.cosmo-model.org/content/model/docum entation/core/cosmoInt2lm.pdf

int2lmint2lm

COSMO topography

GME topography

GME analysis/forecast

COSMO analysis/lbc data

During interpolation, take care of different• horizontal grids and vertical structure (number and placement of layers),• orographic heights (8 m ~ 1 hPa),• surface characteristics (e.g. land/sea, soil types)in GME and COSMO model ..

Run COSMO model (e. g. COSMO_07) forecasts

See: http://www.cosmo-model.org/content/model/docum entation/core/cosmoUserGuide.pdf

COSMOCOSMO

Analysis

Lateralboundary data

Initialized analysisand

forecast files

Lateral boundary data for COSMO are provided by GME at 3- hourly intervals.

COSMO forecast files (GRIB1 (in 2013: GRIB2) code) ma y be produced at hourly(even at ¼ h) intervals.

Free selection of output variables and pressure levels via Namelist parameters(see COSMO User‘s Guide; sections 7.14 and 8 .2)

Run applications based on COSMO forecasts, e.g. wave m odel

Wind Wind componentscomponents U_10M, V_10M U_10M, V_10M areare convertedconverted to to speedspeed and and directiondirection..

COSMO wind COSMO wind forecastsforecasts forfor thethe WAM WAM maymay bebe writtenwritten in a separate GRIB1 in a separate GRIB1 codecode filefile..

WAMWAMWind at 10mforecast

Height and directionof

wind sea and swell

Numerical Weather Prediction at DWD

COSMO-EU

Grid spacing: 7 km

Layers: 40

Forecast range:

78 h at 00 and 12 UTC


1 grid element: 49 km 2

COSMO-DE

Grid spacing: 2.8 km

Layers: 50

Forecast range:

21 h at 00, 03, 06, 09,

12, 15, 18, 21 UTC


Global model GME

Grid spacing: 20 km

Layers: 60

Forecast range:




Numerical Weather Prediction at NMA

COSMO-Ro7

Grid spacing: 7 km

201 x 177 grid points

Layers: 40

Forecast range:


COSMO-Ro2

Grid spacing: 2.8 km

361 x 291 grid points

Layers: 50

Forecast range:

30 h at 00, 12 UTC

Overview of the ASCII Output of the COSMO System

INT2LMYUCHKDAT: Min/Max values of all interpolated fieldsYUDEBUG: Only written if in debugging modeYUTIMING: Timing on all processors

COSMOYUSPECIF: Namelist variables YUCHKDAT: Min/Max values of all fieldsYUPRMASS: Variables averaged over model domain; VMAX , WMAXYUPRHUMI: Humidity variables averaged over model dom ainYUTIMING: Timing on all processorsM_* METEOGRAM-OUTPUT (*: name of point)

Model GRID I; Counting of Grid Points

(1,1)

(startlat_tot, startlon_tot)

(ie_tot,1)j1 ⇒⇒⇒⇒

(1, je_tot)

(endlat_tot, endlon_tot)

(ie_tot, je_tot)

⇑⇑⇑⇑

j2

W ⇒⇒⇒⇒ E

N

⇑⇑⇑⇑

S

(1) COSMO counts the grid points starting from the lower lef t corner to the upper

right one (scanning mode) (see &LMGRID in INPUT_ORG).

ie_tot = (endlon_tot – startlon_tot) / dlon + 1; e.g. i e_tot = (28.0 – 10.0) / 0.0625 + 1 = 289

je_tot = (endlat_tot – startlat_tot) / dlat + 1; e.g. je_tot = (30.0 – 11.0) / 0.0625 + 1 = 305

(2) The first index ( j1 or i) is from west to east, the second one ( j2 or j) is from southto north.

Model GRID II; Arakawa C grid

vi,j

Ti,j ui,j

vi,j-1

Ti+1,j

T: Mass point; most variables are defined here!

u: zonal wind; shifted by half a mesh size to the ea st.

v: meridional wind; shifted by half a mesh size to t he north.

Mesh size (km): ∆x = a cos φ ∆λ and ∆y = a ∆ φ with a: radius of the Earth (6371 km).

At 0°N: cos φ = 1, at 30°N: cos φ = 0.86; at 60°N: cos φ = 0.5; at 80°: cos φ = 0.17 !

The grid “point” value is a representative area aver age over ∆x * ∆y,

e.g. for ∆x = ∆y = 7 km: 49 km 2.

File Name Convention for GRIB Code FilesCOSMO User‘s Guide, Section 6.2, page 45 - 46

Examples of GME files

giff00000000: initialized analysis - used by int2lm to derive an initial state for the COSMO model by interpolation from the GME grid to the COSMO model grid.

gfff00030000: 3-h forecast

gfff01060000: 30-h forecast (1 day, 6 hours)

The GME GRIB code files contain only those points o f the GME icosahedral-hexagonal grid which cover the COSMO do main in question in order to reduce the amount of data to be transfe rred via the Internet; a bitmap is given to tell int2lm which grid points are set.

File Name Convention for GRIB Code FilesCOSMO User‘s Guide, Section 6.2, page 45 - 46

Examples of COSMO files

laf2003092312: initial state (analysis) of COSMO for 23 Sept. 2003 12 UTC; derived from the initialized GME analysis via int2lm

lbff00060000: lateral boundary data at +6 hours

lbff02120000: lateral boundary data at +60 hours (2 days, 12 hours)

lfff01180000: 42-h forecast (1 day, 18 hours) on COS MO model levelslfff01180000p: 42-h forecast, interpolated to pressu re levelslfff01180000z: 42-h forecast, interpolated to height levels (above msl)

Basics of GRIB1 CodeCOSMO User‘s Guide, Section 5.1, page 36 - 41

GRIB1: Gri dded B inary Code Version 1; Binary code of WMO1 GRIB field, e.g. the temperature at 2m above grou nd for a 12-h

forecast is given in the form

PDS: Product Definition Section (Section 5.1.3, page 39 - 40)GDS: Grid Description Section (Section 5.1.4, page 4 1)Data packing of values f i (i = 1, N; where N = ie x je is the total number

of grid points)(1) Subtract the minimum value f min : f i - fmin

(2) Scale f i - fmin such that f max - fmin fits into 16 bits (= 2 bytes)(3) Pack the scaled values S x (f i - fmin ), i = 1, N; data volume is reduced by about 50%.

Attention: “Negative Precipitation” possible due to GRIB code packing!

PDS GDS Packed (2 bytes = 16 bits per value) values at grid points

Basics of GRIB1 CodeCOSMO User‘s Guide, Section 5.1, page 36 - 41

Time flag (Table 5.7, page 41):

0: forecast product valid at reference time + P1 ; e. g. T, U, V, T_2M

2: forecast product valid for a time range P1 to P2 ; e.g. TMAX_2M, TMIN_2M

3: mean (averaged) over time range from P1 (=0) to P2 ; e. g. ASHFL_S, ASOB_S

4: accumulated over time range from P1 (=0) to P2 ; e. g. RAIN_GSP, RAIN_CON

Overview of the COSMO Forecast FieldsCOSMO User‘s Guide, Section 5.1, page 36 - 41

AttentionFor model interpretation, the different time flags can pose a problem:

for example it rains for a certain period (e.g. 1 hour), but at the end of this period there is no cloud at all; thus i t seems to rain out of blue sky.

The time range for extreme values (MAX and MIN temp erature, MAX wind speed at 10m) is set to 6 (1) hours, but can b e modified byNamelist variable hincmxt (for MAX and MIN temperature) and hincmxu (for MAX wind speed at 10m) in &runctl

Overview of the COSMO Forecast FieldsCOSMO User‘s Guide, Section 8.2, page 144 - 147

Distinction between(1) Constant fields; i.e. time independent fields (2) Multi-level fields; i.e. fields on full or half levels of the model (3) Single-level fields; e.g. surface fields, fields at 2 and 10m above

ground (4) Fields interpolated from model to pressure (heig ht) levels and

mean sea level pressure

Distinction between(1) Uninitialized analysis (laf-file)(2) Initialized analysis and forecasts (lif- and lff- files)

Costs of running the COSMO model

Infrastructure• Full internet connectivity (> 1 MBit/s sustained) for the initial and lateral

boundary data of GME; e.g. 27 x 20 MByte for a 78-h forecast; lbc-data at 3-hourly intervals

• Computer (~ 8 - 80 GByte RAM, 50 - 200 GFlop/s sustaine d speed, 1 - 5 TByte disk)

• Graphical display system, printers, network

Staff• 2 to 5 scientists (meteorology, mathematics, physic s) • 1 to 2 programmers (Unix, Fortran, Graphics)

ConsortiumConsortium forfor Small Small scalescale ModelingModeling COSMOCOSMO

DWD DWD (Offenbach, (Offenbach, Germany):Germany):

NEC SXNEC SX--8R, 8R, SXSX--99

MeteoSwissMeteoSwiss::Cray XT4: COSMOCray XT4: COSMO--7 and 7 and

COSMOCOSMO--2 2 useuse 800+4 800+4 MPIMPI--TasksTasks on 402 out of 448 dual on 402 out of 448 dual

corecore AMD AMD nodesnodes

ARPAARPA--SIM (Bologna, SIM (Bologna, ItalyItaly):):IBM pwr5: up to 160 of 512 IBM pwr5: up to 160 of 512

nodesnodes at CINECAat CINECA

COSMOCOSMO--LEPS (at ECMWF):LEPS (at ECMWF):runningrunning on ECMWF pwr6 as on ECMWF pwr6 as membermember--statestate timetime--criticalcritical

applicationapplication

HNMS (Athens, HNMS (Athens, GreeceGreece):):IBM pwr4: 120 of 256 IBM pwr4: 120 of 256 nodesnodes

IMGW (IMGW (WarsawaWarsawa, Poland):, Poland):SGI SGI OriginOrigin 3800:3800:

usesuses 88 of 100 88 of 100 nodesnodes

ARPAARPA--SIM (Bologna, SIM (Bologna, ItalyItaly):):LinuxLinux--IntelIntel x86x86--64 Cluster 64 Cluster forfortestingtesting ((usesuses 56 of 120 56 of 120 corescores))

USAM (USAM (RomeRome, , ItalyItaly):):HP HP LinuxLinux Cluster Cluster

XEON XEON biprocbiproc quadcorequadcoreSystem in System in preparationpreparation

RoshydrometRoshydromet ((MoscowMoscow, , RussiaRussia), ), SGISGI

NMA (NMA (BucharestBucharest, , RomaniaRomania):):IBM Cluster LINUXIBM Cluster LINUX

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COSMO Help & usage

• Ask for a COSMO contract for scientific evaluation (valid until end of 2012); e-mail to [email protected]; after your Director has signed and returned the contract you get access to the COSMO-model sources.

• If you need support during installation of the COSMO-model: e-mail to [email protected].

• Ask for topographical data for your COSMO-model domain, e.g. at a grid spacing of 0.0625° (~ 7 km); e-mail to [email protected].

• Ask for GME data corresponding to your COSMO-model domain e-mail to [email protected].

• Create COSMO-model products (e.g. via GrADS); if you need help, e-mail to [email protected].

• Implement the operational scheduler of M. Gertz; e-mail to [email protected].

Thank you for your attention !

Questions ?

cosmo overview n - clm-community · short overview of the cosmo model system ... 20 km and 60...

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