ANNUAL WWW TECHNICAL PROGRESS REPORT ON THE GDPS

COUNTRY: Australia CENTRE: NMOC Melbourne

January 2002

1. SUMMMARY OF HIGHLIGHTS (2001):

Meteorological, Oceanographic and Computer Systems:

2. EQUIPMENT IN USE AT CENTRE:

The following table shows the main computer systems used in NMOC Melbourne, with their basic functions:

Peripheral Equipment:

Magnetic Cartridge Archive System:

StorageTek Mass Store 4400 ACS (Automatic Cartridge System)

1 StorageTek 9710 Library Storage Module (with a 37 TB capacity)

6 DLT (Digital Linear Tape) Units

24 drives, for 9840 fibre channel tapes, in silo (10 for SAM-FS, 8 for MARS and 6 for backup)

Hardcopy Printers/Plotters:

HP DesignJet 1055cm plus and 650C plotters

HP LaserJet 5 SiMX printers

HP LaserJet 4500DN

HP DeskJet 1600CM

Software in use at Centre:

The overall computer environment in the NMOC is mainly Unix. A real-time data base, currently using ORACLE 8.1.7.0.0, is used for storage of observational data and grids from the various NWP systems. The U.S. Navy's Environmental Operational Nowcasting System (NEONS) software is commonly used for accessing the data base. The operational NWP models are written mainly in Fortran, with many of the associated files having the NetCDF structure. Most displays are produced using the NCAR graphics package and IDL. The UK Met. Office's Horace (V3.71) system is used to prepare, in an on-screen mode, manual-computer products for: significant weather prognoses, Australian Region surface analyses and prognoses and Southern Hemisphere surface analyses. Sam-fs is currently being used for magnetic cartridge archives in the NMOC. The Meteorological Archive and Retrieval System (MARS from the ECMWF) is currently being developed for research and operational use.

Other Systems in use at Centre:

The DIFACS system is used to to disseminate a selection of basic analysis and prognostic charts, and some satellite imagery, to the Bureau's regional offices and some outside users. MCIDAS is used for comprehensive interaction and display of satellite imagery and products, observational and gridded data, and is also a major component of the Australian Integrated Forecast System (AIFS). Products from the NWP systems are written to internal and external (www.bom.gov.au) web servers. Magnetic cartridge archives are kept of various NWP products with Australian region analyses available back to 1970 and Southern Hemisphere analyses back to 1972. Hard copy and microfilm archives of charts also exist. An aviation system, which interacts with the WAFS data, is used to view and display the data and prepare the various flight and route forecasts. Regular statistics (including S₁ skill scores, root mean square errors and anomaly correlations) monitoring and comparing the performance of the NMOC's NWP systems (and also some overseas NWP models) are also produced.

3. DATA AND PRODUCTS FROM GTS IN USE:

The following table gives a list of the major observation report types used in the NMOC Melbourne and the approximate numbers received in a 24-hour period:

The following Gridded Products are also received in NMOC Melbourne:

GRIB (ECMWF)

GRIB (EGRR)

GRIB (KWBC)

GRIB (JMA)

GRID (ECMWF)

4. DATA INPUT STREAM:

Automated. (Some manual intervention is available for correction of reports.) The observational data, along with NWP gridded data, is stored in a real-time relational data base system (ORACLE/NEONS).

5. QUALITY CONTROL SYSTEM:

Validity checks are currently confined to within the respective assimilation or analysis schemes. Some gross checking outside these schemes may eventually be installed.

6. MONITORING OF THE OBSERVING SYSTEM:

Monitoring of the observing system is carried out. The quantity of data available is monitored in real-time to ensure that reports are being received reliably and are made available to the operational systems. For the global system, statistics on the difference between observations and the first guess and analysis fields are routinely prepared to identify any problems with either the analysis system or individual data types. Lists of rejected data are also used to identify unreliable reporting from particular observing platforms.

7. FORECASTING SYSTEM:

There are three major operational analysis and forecast systems (viz. the global GASP, regional LAPS and the tropical TLAPS) in the NMOC Melbourne. A mesoscale version of LAPS, called MESO_LAPS, provides additional high resolution forecast products over 3 smaller domains (viz., Australia, Sydney and Melbourne). The domains for each of these systems are shown in the figure below. The regional and tropical systems are dependent on the global system for their lateral boundary conditions, whereas the 3 MESO_LAPS systems are all nested in LAPS. An additional system, called TC_LAPS, is run to provide tropical cyclone, and other tropical guidance, for the region. (The possible extent of this guidance is also depicted in the figure below.) Manual intervention is used for mean sea level pressure in both the global and regional systems. The resulting hemispheric "pseudo-observations" for mean sea level pressure are disseminated on the GTS. The tropical and Australian region

limited area systems use bogus moisture data derived from GMS satellite imagery together with a tropical cyclone synthetic specification scheme. An additional feature of the tropical system is its dynamical nudging. Output from the global system is also used in the cold start procedure for the Australian region and tropical systems. It is noted that the MESO_LAPS systems do not have their own separate analyses but currently use initial (and boundary) conditions derived directly from LAPS.

Domains of the operational NWP systems in NMOC Melbourne.

The global, Australian region and mesoscale streams have associated sea-state systems. There are a large number of other parts to the basic scheme. These include systems for sea surface temperature analysis, environmental emergency response, generation of weather elements from model output (MOF), amendment and dissemination of aviation products, MCIDAS, archives, verification, display and dissemination of products. A schematic representation of the overall system is shown in the figure below.

Schematic representation of the operational analysis and prediction system in NMOC.

7.1 System Run Schedule and Forecast Ranges:

At the present time, the centre produces major analyses at 00 and 12 UTC daily for the globe, Australian region and a tropical domains. Global forecasts out to 10 days, Australian region and tropical forecasts out to 48 hours, mesoscale forecasts out to 36 hours, and special tropical cyclone forecasts out to 72 hours are produced off these major analyses. The ECMWF's Supervisor Monitor Scheduler is used to initiate and monitor the various tasks in the operational NWP suite. An approximate daily schedule for the main NWP systems is shown in the table below (with the times during the daylight saving months, November to March, shown in brackets).

System Run Schedule and Forecast Ranges

7.2 Medium-range Forecasting System (4-10 DAYS):

The acronym GASP is given to the Global ASimilation and Prognosis system, which produces medium-range forecast products out to 10 days. Post-processed products from this system are disseminated on the GTS in GRIB form, nationally through "DIFACS" and MCIDAS, and also via Radio-facsimile broadcasts (AXI and AXM).

7.2.1 Data Assimilation, Objective Analysis and Initialization:

Assimilated data: Mean sea level pressure (surface network, ships, drifting buoys), thickness (radiosondes, satellite retrievals), moisture (dew points, satellite precipitable water), wind (rawinsonde, aircraft, geostationary satellites, constant level balloons), cloud-clear radiances (from NOAA orbiting satellites).

Assimilation cycle, including cut-off time: 6 hourly cycling. H+6 cut-off.

Method of analysis: Multivariate statistical interpolation + univariate O.I. for moisture, one- dimensional variational retrievals (1DVAR).

Analysed variables: Geopotential, wind, moisture.

First guess: 6 hour forecast from previous cycle.

Coverage: Global.

Horizontal resolution: Triangular 239.

Vertical resolution: 29 sigma levels (0.991, 0.975, 0.950, 0.925, 0.900, 0.875, 0.850, 0.800, 0.750, 0.700, 0.633, 0.566, 0.500, 0.433, 0.366, 0.320, 0.290, 0.260, 0.230,

0.200, 0.170, 0.140, 0.110, 0.090, 0.070, 0.050, 0.030, 0.020, 0.010)

Initialization: Incremental non-linear normal mode.

7.2.2 Model:

Basic equations: Spectral primitive equations.

Independent variables: latitude,longitude,,t

Dependent variables: log p*,T,q,vorticity,divergence.

Numerical technique:

horizontal: Spectral.

vertical: Finite difference.

time: Semi-implicit semi-Lagrangian.

Integration domain (in horizontal and vertical): Global, surface to 10 hPa (approx.).

Horizontal and vertical resolution, time step: Triangular 239, 29 sigma levels,

600 sec.(approx.).

Orography, gravity wave drag: Both included.

Horizontal diffusion: Included.

Vertical diffusion: Included.

Planetary boundary layer: Included.

Treatment of sea surface, earth surface and soil: Included.

Radiation: Diurnal cycle, diagnostic clouds, interactive optical properties.

Convection (deep and shallow): Included.

Atmospheric moisture: Included.

Boundaries: Stand alone.

Albedo: Climatology.

SST Analysis: Weekly (1⁰x1⁰).

7.2.3 Numerical Weather Prediction Products:

The following post-processed fields are available from GASP:

7.2.4 Operational Techniques for Applications of NWP Products:

The 10 m wind field from GASP is used to drive a global sea-state model.

7.2.5 Ensemble Prediction System:

An Ensemble Prediction System based on the GASP system is currently being run in test mode in real-time in NMOC Melbourne. The 33-member ensemble system is running at the resolution: T79/19L and producing forecasts out to 10 days, off 00 and 12 UTC. Singular vectors are used to perturb the initial state derived from GASP. These perturbed states are then used as the initial conditions for each of the ensemble members.

7.3 Short-range Forecasting System (0-72 HRS):

The Australian region Limited Area Prediction System (LAPS), the Tropical Limited Area Prediction System (TLAPS) and the MESOscale Limited Area Prediction System (MESO_LAPS) provide short-range forecasting guidance and products that are disseminated nationally through "DIFACS" and MCIDAS and also via Radio-facsimile broadcasts (AXI and AXM). TLAPS and TC_LAPS, for specific tropical cyclone guidance, are run on behalf of RSMC Darwin. Again it is noted that, at present, the 3 MESO_LAPS systems do not have their own assimilation, or analysis, but use an initial starting condition derived directly from LAPS. It is also noted that TC_LAPS runs in 2 basic parts. The first preparatory part produces analyses and prognoses over a large domain, or what is called the Large Scale Environment (LSE), and the second part then generates analyses and forecasts at a higher resolution on a relocatable domain centred on the tropical cyclone (and nested within the LSE part).

7.3.1 Data Assimilation, Objective Analysis and Initialization:

Assimilated data: Surface synop, ship, drifting buoy, radiosonde, rawinsonde, GTS TOVS, locally processed TOVS, GTS and locally derived GMS cloud drift winds, aircraft single level winds, bogus MSLP ("pseudo-observations"), synthetic GMS moisture data, tropical cyclone synthetic data.

Assimilation cycle, including cut-off time: 6 hourly cycling; cut-off: LAPS: H+2 hr,

TLAPS: H+4 hr.

Method of analysis: Multivariate statistical interpolation + univariate statistical interpolation for moisture.

Analysed variables: Geopotential, wind, moisture.

First guess: 6 hour forecast from previous cycle.

Coverage: LAPS: 17.125⁰N-65.0⁰S, 65.0⁰E-184.625⁰E

TLAPS: 44.25⁰N-45.0⁰S, 70.0⁰E-188.25⁰E

TC_LAPS: 56.75⁰N-55.0⁰S, 70.0⁰E-164.75⁰W (LSE), 27.0⁰x27.0⁰ (Relocatable)

Horizontal resolution: LAPS and TLAPS: 0.375⁰

TC_LAPS: 0.75⁰ (LSE) and 0.15⁰ (Relocatable)

Vertical resolution: LAPS, TLAPS: 29 sigma levels (0.9988, 0.9974, 0.9943, 0.9875, 0.9750, 0.9625, 0.9500, 0.9250, 0.9000, 0.8750, 0.8500, 0.8000, 0.7500, 0.7000, 0.6000, 0.5000, 0.4500, 0.4000, 0.3500, 0.3000, 0.2750, 0.2500, 0.2250, 0.2000, 0.1750, 0.1500, 0.1000, 0.0700, 0.0500)

TC_LAPS: 19 sigma levels (0.9910, 0.9750, 0.9500, 0.9000, 0.8500, 0.8000, 0.7500, 0.7000, 0.6000, 0.5000, 0.4000, 0.3500, 0.3000, 0.2500, 0.2000, 0.1500, 0.1000, 0.0700, 0.0500)

Initialization: LAPS and MESO_LAPS: Digital filtering technique.

TLAPS and TC_LAPS: diabatic dynamical nudging scheme incorporating GMS IR imagery.

(For Tropical Cyclones: Synthetic vortex specification.)

7.3.2 Model:

Basic equations: Grid primitive equations.

Independent variables: x,y,z,t

Dependent variables: P*,T,q,u,v.

Numerical technique:

horizontal: Finite difference.

vertical: Finite difference.

time: Semi-implicit.

Integration domain (in horizontal and vertical):

LAPS: 17.125⁰N-65.0⁰S, 65.0⁰E-184.625⁰E, surface to 50 hPa (approx.)

TLAPS: 44.25⁰N-45.0⁰S, 70.0⁰E-188.25⁰E, surface to 50 hPa (approx.)

MESO_LAPS:

Australian: 4.875⁰S-55.0⁰S, 95.0⁰E-169.875⁰E, surface to 50 hPa (approx.)

Sydney: 30.05⁰S-38.00⁰S, 147.00⁰E-154.95⁰E, surface to 50 hPa (approx.)

Melbourne: 34.05⁰S-41.00⁰S, 141.00⁰E-150.45⁰E, surface to 50 hPa (approx.)

TC_LAPS:

LSE: 56.75⁰N-55.0⁰S, 70.0⁰E-164.75⁰W, surface to 50 hPa (approx.)

Relocatable: 27.0⁰x27.0⁰ , surface to 50 hPa (approx.).

Horizontal and vertical resolution, time step:

LAPS: 0.375⁰ , 29 sigma levels, 40 sec

TLAPS: 0.375⁰ , 29 sigma levels, 40 sec

MESO_LAPS:

Australian: 0.125⁰, 29 sigma levels, 10 sec

Sydney: 0.05⁰, 29 sigma levels, 5 sec

Melbourne: 0.05⁰, 29 sigma levels, 5 sec

TC_LAPS:

LSE: 0.75⁰ , 19 sigma levels, 40 sec

Relocatable: 0.15⁰ , 19 sigma levels, 15 sec.

Orography, gravity wave drag: Included.

Horizontal diffusion: Included.

Vertical diffusion: Included.

Planetary boundary layer: Included.

Treatment of sea surface, earth surface and soil: Included.

Soil moisture analysis: Included in LAPS, TLAPS, TC_LAPS and MESO_LAPS.

Radiation: Diurnal cycle, diagnostic clouds, interactive optical properties.

Convection (deep and shallow): Included.

Atmospheric moisture: Included.

Boundaries: LAPS, TLAPS and TC_LAPS (LSE): Lateral boundaries from GASP.

MESO_LAPS (3 domains): Lateral boundaries from LAPS.

TC_LAPS (Relocatable): Lateral boundaries from LSE TC_LAPS.

Albedo: Climatology.

SST Analysis: Weekly (1⁰x1⁰) - in LAPS, MESO_LAPS (Australian), TLAPS and TC_LAPS.

Daily (0.25⁰x0.25⁰) - in MESO_LAPS (Melbourne and Sydney).

7.3.3 Numerical Weather Prediction Products:

The following post-processed fields are available from the Limited Area Prediction Systems:

7.3.4 Operational Techniques for Applications of NWP Products:

The 10 m wind field from LAPS and MESO_LAPS are used to drive sea-state models for the Australian region and smaller domains. The Model Output Forecast (MOF) system, which is driven by LAPS and GASP, is used to produce numerous weather elements including temperatures (minimum, maximum, dry bulb, dew point, wet bulb and ground minimum), wind (speed and direction), precipitation, cloud amount, evaporation, sunshine and visibility. Meteograms, giving time series of meteorological variables, are also available. In addition, there is available thunderstorm, based on a decision tree approach, and cold-season tornado ("COLDIES") guidance, with input from (the Australian domain) MESO_LAPS.

7.4 Specialized Forecasts:

An analogue/regression tropical cyclone model ("TOPEND") is also available for providing guidance to the Australian Tropical Cyclone Warning Centres, but is rarely used. Specialized sea-state forecasts are provided for the North West Cape and Bass Strait gas and oil fields.

7.4.1 Sea Wave Models:

The following table summarises the characteristics of the seastate system in the NMOC:

7.4.2 Storm Surge System:

A system capable of forecasting storm surges caused by tropical cyclones is currently driven by wind and pressure field distributions defined according to the central pressure and maximum wind radius bogussed for tropical cyclones by Darwin RFC.

7.4.3 Air Dispersion Model:

An air dispersion, or transport, system is available for running on demand and can produce forecast trajectories, concentrations (or exposures) and depositions for nuclear accident, volcanic ash, smoke and other episodes. Currently, the operational Environmental Emergency Response system consists of the Hybrid Single_Particle Lagrangian Integrated Trajectories (HY-SPLIT Version 4.0) system, developed at the NOAA Air Resources Laboratory, with meteorological input from the operational NWP systems in NMOC (viz., GASP, LAPS, TLAPS, and MESO_LAPS). Analysed backward trajectories are also available from GASP, LAPS and TLAPS in operations.

7.4.4 Solar Ultraviolet (UV) Radiation Forecast System:

Forecasts out to 36 hour forecasts of a UV index (defined as the product of the UV irradiance and a human skin response function) are produced operationally. The system analyses ozone concentrations, available from the global 120 km GTS TOVS data, using 2-dimensional univariate statistical interpolation. Forecasts of the ozone distribution are then computed using isentropic fields derived from GASP output. From vertical profiles of temperature and ozone, the UV index is calculated. Currently, forecasts of the UV index are produced, once per day, after completion of the 1200 UTC run of GASP.

7.5 Extended-range Forecasts (10 - 30 DAYS): Not applicable yet.

7.6 Long-range Forecasts (30 DAYS - 2 YEARS):

A three-month rainfall seasonal climate outlook is prepared. Each month, a risk-assessment for three-month total rainfall across Australia is issued mid-month for the three-month period starting the following month. Probabilities are calculated for the three-month total rainfall being in the lowest one-third of historical falls (tercile 1), the middle one-third (tercile 2), and the upper one-third (tercile 3). The technique used is discriminant analysis, with the inputs being derived from recent Sea Surface Temperature (SST) patterns. Subsidiary techniques involved in the forecast model include principal component analysis of SSTs for the Pacific Ocean, Indian Ocean and Southern Ocean, and principal component analysis of rainfall patterns across Australia. SST EOF (Empirical Orthogonal Function) loadings, at one and three months lag, for the Pacific Ocean ENSO pattern and the Indian Ocean pattern are the current predictor inputs. The tercile probabilities, computed across Australia on a 1⁰x1⁰ grid are published in the form of contoured maps, tabulated averages for the 107 Australian rainfall districts, and tabulated interpolations for cities and towns around Australia. Similar outlooks are now provided for above/below median and for both maximum and minimum temperatures.

Additional guidance at the rainfall district level is presented in the form of stratified rainfall climatologies based on recent values of the SOI (Southern Oscillation Index). Rainfall outcomes for eastern Australia, obtained from SOI analogues, are also described.

Additional forecasts for NINO3 are provided based on an intermediate coupled atmosphere-ocean with sub-surface ocean temperature assimilation. A coupled atmosphere-ocean GCM (General Circulation Model) combined with a sub-surface ocean temperature data assimilation system has been developed and is currently being used to routinely provide forecasts which are currently being assessed.

8. VERIFICATIONS OF PROGNOSTIC PRODUCTS:

An annual summary of verification statistics for 2001, for the Australian regional and global schemes, is given in the following tables.

The following abbreviations have been used in the tables:

S1 - 30 day mean Teweles skill score over Australian verification area

r - anomaly correlation coefficient between forecast heights and climatology over Australian verification area

PERSIS - 24, 36 or 48 hour persistence prediction

REGN - Australian Regional LAPS (Limited Area Prediction System)

GASP - Global Assimilation and Prognosis model

RMSE - Root Mean Square Error

Note:

The LAPS and GASP results are with respect to their own analyses.

8.1 Skill Scores and Anomaly Correlation Coefficients:

24 HR VERIFICATION STATISTICS - AUSTRALIAN REGION 2001

BASE TIME: 0000UTC - VALID TIME: 0000UTC