Date Time Title Speaker Affiliation 14 February (Fri) 10 am Moisture Feedbacks in the tropical atmosphere Lyle Pakula Colorado State University, U.S.A. 14 February (Fri) 2 pm Recent Developments in NWP at the MetOffice Andrew Lorenc UK Met Office 17 February (Mon) 2 pm Research Plans for NWP at the MetOffice Andrew Lorenc UK Met Office 19 February 10 am New geostationary satellites in our regoin John LeMarshall BMRC 20 February (Thurs) 2 pm Assimilation of cloud and precipitation data Andrew Lorenc UK Met Office 21 February (Fri) 2:30pm 12th floor informal talk on multidecadal trends in CAPE Andrew Gettelman NCAR 26 February 10 am Best Objective Guidance Forecasts for Public Weather Frank Woodcock BMRC 5 March 10 am Public-private partnerships (PPP) in meteorology: How applicable is the U.S. model? Don Gunasekera BMRC 13 March (Thurs) 10 am ENSO hindcast results from the Hamburg coupled model and from the DEMETER Super Ensemble Noel Keenlyside Max-Planck-Institut 19 March 10 am Validating model clouds and their optical properties using Geostationary satellite imagery Zhian Sun BMRC 20 March (Thurs) 10 am Change, change management, and coping with change Joan Pegram Change Consultant 28 March (Fri) 10 am What does the customer think? Results of the regular seasonal telephone surveys with the Australian public. Ruth Byrne Services Policy Branch, BoM 31 March (Mon) 2pm IPCC Observed Climate Variability and Change Chris Folland UKMO 1 April (Tues) 2pm Detecting an anthropogenic influence on Australian climate David Karoly University of Oklahoma 2 April 10 am Probabilistic Precipitation Forecasts from Deterministic Forecast Models Beth Ebert BMRC 9 April 10 am Error correlations of a wave model forced by GASP Diana Greenslade BMRC 15 April (Tues) 10 am Rain Accumulation and Lightning Activities of East-Asian Monsoon Rain: Videosonde Observations Tsutomu Takahashi Obirin University 16 April 10 am Information on the transition from GMS-5 to GOES-9 Mike Willmott Space Based Observations Section, BoM. 23 April 10 am Progress on streamlining the forecast process via a knowledge-based system Harvey Stern Victorian Regional Office, BoM 30 April 10 am Identifying cloud regimes using ISCCP data - A Western Pacific and ARM example Christian Jakob BMRC 5 May (Mon) 10 am The HYCOM ocean forecasting system Eric Chassignet University of Miami 7 May 10 am Impacts of TC Zoe in the South Pacific Linda Anderson-Berry BoM Services Policy Branch 14 May 10 am Short-term Predictability Issues in the Tropics Kamal Puri BMRC 19 May (Mon) 10 am Simulating the Climate of Southern Africa using the Hadley Centre Regional Climate Model Debbie Hudson BMRC 21 May 10 am The impact of shear on TC genesis in TCLAPS Kevin Tory BMRC 29 May (Thu) 10 am The Cloud Feedback Model Intercomparison Project: The Start-up Phase Bryant McAvaney BMRC 3 June (Tue) 10 am Meteorological Applications of Wind Profilers: Studies of Frontal Systems and Precipitation Chris Lucas University of Adelaide 4 June 10 am Verification of Seasonal Rainfall Outlooks for Australia, 1993-2002, Using Multilevel Modelling Garry Anderson University of Melbourne 18 June 10 am Tropical Cyclone Forecasting Scheme for New Caledonia Sebastien Chene METEO-France/BMRC 26 June (Thu) 10 am Can we detect hail and lightning with a radar and how do we know? Peter May BMRC 2 July 10 am Verification of the operational seasonal forecasting system R.Fawcett, D.Jones, G.Beard NCC 9 July 10 am The EC land surface model with variable soils and vegetation: Is it better? Harald Richter BMRC 16 July 10 am 1. Overview of research in CS and math at the Center for Applied Scientific Computing. 2. Current work in the Overture project (adaptive overlapping grids, and related topics). David Brown California Institute of Technology 21 July (Mon) 2 pm, 5th floor Meteorological Aspects of the Canberra Bushfires of 18th January 2003 Clem Davis Canberra Met Office 23 July 10 am Climate-vegetation interactions and development of Canadian Terrestrial Ecosystem Model (CTEM) for CCCma Coupled Carbon-Climate Model Vivek Arora Canadian Centre for Climate Modelling and Analysis 30 July 10 am Implementation of Productivity Commission Cost Recovery Enquiry Recommendations: Implications for the Bureau of Meteorology Don Gunasekera BMRC 6 August 10 am High Latitude Influences on the Monsoon Noel Davidson BMRC 11 August (Mon) 11 am Do climate forecasts help in forecasting the Australian wheat crop? Graeme Hammer Queensland Department of Primary Industries 13 August 10 am Observations of volcanic clouds in the Asia-Pacific region Andrew Tupper BoM, NT Regional Office 20 August 10 am Understanding Climate Model Feedbacks Rob Colman BMRC 27 August 10 am TBA Harry Hendon BMRC 3 September 10 am Tropical Interannual Variability in the 1st BMRC "Standard Coupled Climate Model" Aihong Zhong BMRC 10 September 10 am TBA Guomin Wang BMRC 17 September 10 am Trends in Australian Rainfall Ian Smith CSIRO 19 September (Fri) 10 am Meteorological aspects of the Alpine fires, Victoria 2003 Tony Bannister BMRC 24 September 10 am On the ability of NWP centers to capture the 1st Southern Hemisphere warming that occurred in Sept-Oct 2002 Greg Roff BMRC 24 September 2pm Potential vorticity tendency and tropical cyclone motion Johnny Chan City University of Hong Kong 1 October 10am The Impact of Anthropogenic climate change on tropical cyclones in the Australian region John Mcbride BMRC 9 October 10am Evaluation of Detrainment and Microphysics Parameterizations in the NCEP GFS Single-Column Model Using Results from a CRM Steve Krueger University of Utah 10 October 10am Daytime Convective Development over Land Wojciech W. Grabowski NCAR 17 October 10am The Cloudsat Mission and the Study of the Global Water Cycle Graeme Stephens CSU 17 October 2pm Climate Modeling on the Icosahedron David Randall CSU 20 October 10am ECMWF's New Reanalysis - ERA40 Martin Miller ECMWF 21 October 10am Evaluation of the ERA-40 surface water budget and surface temperature for the Mackenzie River basin Alan Betts Atmos. Res. 21 October 2pm Global Remote Sensing of Surface Albedo and Land-Cover Type From the MODIS Instrument Alan H. Strahler Boston University 22 October 10am Coupling between CO2, water vapor, temperature and radon and their fluxes in an idealized equilibrium boundary layer over land Alan Betts Atmos. Res. 23 October 10am Strides, steps and stumbles in the annual march Brian Mapes NOAA-CIRES CDC 29 October 10am Getting the best out of your Managed Desktop PC's Hank Kloppenborg COSB 12 November 2pm The Relevance of Adjoint Models Dr Ron Errico Goddard Earth Science Technology Center and Goddard Space Flight Center Global Modeling and Assimilation Office 14 November 10am The Changing Culture of Atmospheric Science Dr Ron Errico Goddard Earth Science Technology Center and Goddard Space Flight Center Global Modeling and Assimilation Office 3 December 10am Effect of Air-Mass Predictor Choice on the AIRS Bias Correction at the Met Office Brett Harris BMRC 10 December 10am Is "Soil Moisture" an Observable Quantity? Bryant McAvaney BMRC 17 December 10am Contributions of External Forcings to Southern Hemisphere Annular Mode Trends Julie Arblaster BMRC/NCAR

The normal venue is the BMRC conference room (Floor 13).

`Traditionally,' seminars are at 10 am on Wednesdays with duration of 30 to 50 minutes + questions. Dates and times other than the usual Wednesday morning are shown in bold print.

Emphasis is on work in progress. Partly because of this, the schedule is susceptible to change.
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Videotapes of several seminars that have been given during the year are available for loan from the National Meteorological Library. These are indicated by a camera icon next to the seminar date. In addition, a list of seminars held in the library can be found on the catalogue by entering Series: BMRC, Format: Video. If you would like to have a talk videotaped please contact the seminar coordinator.

If you would like to know more details of coordinating seminars (if, for example, you are hosting a visitor who will be giving a seminar and the regular seminar coordinator is not available), have a look at the document, "Instructions for BMRC Seminar Coordinator"

For further details contact the seminar coordinator, Brett Harris, on 03 9669 4388, b.harris@bom.gov.au

ABSTRACTS

This investigation performs a series of three tests in a high-resolution (2.4km), large domain (20,000km) 2D CRM, based on an LES model of convection with the explicit effects of radiation coupled to the CRM. The first test prescribes a homogeneous radiative cooling profile across the domain, thus turning off the cloud-radiative affects. The second test incorporates cloud-radiative affects but with a diurnally averaged forcing, thus ignoring the effects of spatial and temporal varying radiative forcing. The third test uses a spatially varying dirunal cycle, to simulate night and day, that propagates such that any point in the model experiences a realistic 24 hour dirunal cycle of solar forcing. Similar tests to the first two experiments here have been performed by Grabowski (2000) and Tompkins and Craig(1998) and the goal of this investigation was to build a more complete view of the multi-scale interactions and resultant feedbacks between convection and the dynamical and thermodynamical states of the atmosphere. Furthermore, particular attention is given to the physical cloud structures in the experiments and how these are affected by the various modes of radiative forcing and subsequent effects on the model feedbacks in the context of cloud efficiency.

This investigation finds that the evolution to a quasi-equilibrium state is an important part in understanding the final state itself and that several feedbacks play an important role in this process, the most important being feedbacks between moisture and convection. One such feature not addressed by previous research was the importance of cloud-radiation interactions on shallow convection and subsequent effects of shallow convection on the moisture feedbacks. Feedbacks involving shallow convection significantly contribute to the positive feedbacks that lock precipitation into position. Furthermore, the state of the atmosphere is found to have three independent scales of adjustment, that is the convective, dynamic and thermodynamic scales, all of which affect the state of clouds in the model. Some qualitative explanations are given to describe how the convective, meso and synoptic scales interact with each other to organise the convection and dynamical structures observed. Finally, the diurnal cycle reveals some striking similarities to nature while also demonstrating the importance of a `critical inefficiency' feedback. This negative feedback on convection occurs when upper-level convective and radiative warming, over a large region, is not dissepated fast enough to allow the region to destabilise for more convection. This shut-down of convection over a large region has dramatic effects on the large scale circulations and location of precipitation.

The talk describes how and why the system works. It includes results from recent simulations to investigate the impact of bias-correction of contributing forecasts and optimal weighting versus averaging in combining forecasts.

Being a complex, objective system, there is ample scope for controlled experiments to improve performance further. Hence, a focus of the talk will be our plans for the next generation of BOG.

This work is being performed under Demeter, an EU project to implement, test, and evaluate the performance of a super-ensemble of ENSO climate models. This project involves six European climate models, the output of which is to be used in crop and health models to access the economic benefits of the Demeter system. Results are clearly indicating the superiority of a multi-model approach, and shall be discussed.

A new radiance code derived from the Edwards and Slingo radiation scheme and several cloud optical property schemes have recently been implemented into the system. The forward calculations were performed using both the operational radiative transfer code and this new code and the results were compared with satellite measurements. The effects of different cloud optical property schemes, cloud particle scattering and cloud phase state were investigated. The results have shown a dramatic improvement in the comparison due to changes in the model physical parameterizations.

The major achievement obtained in this study is the implementation of a new ice water content diagnostic scheme developed on the basis of lidar-radar data collected at the Southern Great Plains, the cloud and radiation testbed site of the Atmospheric Radiation Measurement (ARM) program in Oklahoma. Using this scheme in conjunction with the new forward radiance code the modelled brightness temperature using fields from the global NWP model is significantly improved.

This presentation is founded in a background which includes: Organizational Theory and Management Practice, Organizational Analysis, Sociology, Ethics, Critical Theory, Developmental and Learning Theory, Gender Studies, Social Psychology, Institutionalism and Political Studies.

The seminar will specifically address the following questions:
· What is Change?
· What is Change Management? (Placed within the context of organizational theory and management practice)
· How do people cope with Change?
The thrust is not the usual one of promoting Management's position but intends to stimulate and prepare Employees themselves to take up the challenge of inevitable organizational change and the responsibility for the betterment of their own organizational position that Change Management presents.

Dr Joan Pegram has spent 25 years in different aspects of organizational life advertising, publishing, commerce, education and consulting. Her academic background in Communications, Change Management and Organizational Transformation has made her passionate about the individual breaking the hold of conformity, tapping into their creative energy and achieving success in those areas of their life that are important to them. She integrates her professional background, personal insight and analytical ability in her business as a personal and professional coach.

The presentation will cover the types of weather-dependent decisions made by the general public, the types of weather information they use to make their decisions, how far ahead and how often they access information, and whether the information obtained meets their requirements and is available in time to make their decision. The popularity of different media to access weather information will also be discussed, as will perceptions of forecast accuracy for various weather elements and short (24 hour) and medium (2-4 day) range forecasts, and overall satisfaction with the Bureau.

The Third Assessment Report of the Intergovernmental Panel on Climate Change (IPCC) in 2001 reported that there has been an increase of about 0.6C in the global-mean temperature over the last century. The IPCC Assessment concluded that most of the observed global warming over the last 50 years was likely to have been due to anthropogenic factors; increasing greenhouse gases and sulphate aerosols in the atmosphere. All studies that have successfully detected an anthropogenic influence on recent climate change have considered global scale variations. It is harder to identify the effects of anthropogenic climate change on regional scales than on global scales because of the greater magnitude of the internal climate variability relative to forced climate change signals.

The results from a regional climate change detection and attribution study over Australia are described. Observed climate variability and change in the Australian region are compared with climate model simulations of natural and anthropogenically-forced climate variations over the 20th century. A number of simple indices of climate variability and change are defined, including the area-mean temperature over land, the land-ocean temperature contrast, and the mean diurnal cycle and annual cycle of temperature over land. These indices are all expected to show a common response to increasing greenhouse gases but are reasonably independent for natural climate variations.

The simulated interannual variability and correlation structure of the indices, averaged over the Australian region, compare reasonably well with the observed indices. The observed trends over the last 50 years in all the indices over Australia are consistent with simulated trends in model experiments that include increasing greenhouse gas and sulphate aerosol concentrations. The observed mean warming over the last 50 years is not consistent with internal climate variability. Hence, it is likely that a significant fraction of the observed warming in the Australian region over the last 50 years is due to human activity.

It is possible to obtain PQPFs from the output of deterministic model runs using an upscaling strategy. In practice we do not take a high resolution QPF at face value, but rather do a mental conversion to probability of significant rain within the broader region. This process can be objectified by obtaining the distribution of predicted rainfall in the "neighbourhood" of a grid box, defined by a spatial window size Dx and a temporal interval Dt, from which rain probability can be computed. Forecast products include maps of rainfall probability exceeding certain thresholds, and box-and-whiskers meteograms showing rainfall range and uncertainty. Neighbourhood-based PQPFs clearly outperform deterministic forecasts according to several measures. The probabilistic skill of these products initially increases with increasing neighbourhood size, then begins to decrease as the window is further increased. The optimal window size appears to depend on the intensity of the forecast rain system, suggesting the possibility of dynamically choosing an appropriate window size.

Forecasts from the neighbourhood technique will be compared to the station-based Best Objective Guidance (BOG) approach, and to the Poor Man's (multi-model) ensemble.

In this work, differences between global wave model output and satellite altimeter Significant Wave Height observations are examined over a four-year period. Results for the general isotropic case will be presented. In addition, error correlations from ascending and descending satellite ground tracks are considered separately in an attempt to determine the level of anisotropy in the wave model error correlations.

Another method that has been used to determine the error correlations is the so-called "NMC method", in which model forecasts are compared to model analyses. Results using this method will also be presented and discussed.

1. The subtle difference in lightning activity between the maritime continent and the west Pacific is due to the difference in number concentrations of graupel and ice crystals.

2. Monsoon rain systems can be subdivided into four groups by differences of the precipitation mechanisms. Freezing processes are most important in the west Pacific while mixed rain processes prevail over the maritime continent.

3. In some cases with mixed precipitation areas, the rain accumulation process is through rapid growth of graupel near the freezing level. Cell to cell merging was observed in this instance and torrential rain resulted.

A three dimensional microphysics cloud model was used to increase understanding of the underlying physics.

In the last two years, GMS-5 has developed a few problems. The spin scan motor on board the spacecraft is being subjected to a large torque which is outside tolerance limits for the motor. This limits the scan for each image and the southern part of the imagery is disappearing by a few degrees per month. The fuel used to manoeuvre the spacecraft is slowly being exhausted. This means that the satellite will increase its inclination with respect of the earth and the images will start to get noisier and noisier as the satellite moves outside the fixed ground station antenna=s field of view.

To compensate for the probability that GMS-5 may not last until the launch of MTSAT- 1R, JMA and the National Oceanographic and Atmospheric Administration (NOAA) came to an agreement to use a standby GOES satellite to back-up GMS-5. GOES-9, which was parked in a geostationary orbit over 1060 west is being moved westward to 1550 East where it is to become the Aback-up@ for the GMS-5 satellite. GOES-9 is a different type of satellite to GMS-5 in many ways. It has more functionality than GMS-5 but still has some similar characteristics. This talk will compare and contrast the differences between GOES-9 and GMS-5, outline the availability of the data and also remove some of the myths that may be in existence concerning these satellites.

A brief look at MTSAT-1R will also be given.

A major benefit of a knowledge-based system is that it incorporates an extensive "bank" of forecaster experience. Ramage (1993) has proposed an "iterative" approach to "locking in" improvements in forecasting methodology. The system's skill increases as new knowledge is incorporated into its operation. Hence, progress is gradually made towards the realisation of Ramage's dream. The system is (therefore) not seen as "yet another" instrument of forecast guidance. Rather, its development is seen as a logical step along the path of having the computer replicate (and ultimately replace) various aspects of the manual side of the forecast process, by systematically "locking in" new knowledge.

The PILOT VERSION of the system was evaluated during November 2001 for the city of Melbourne using a skill score that combines all features of a forecast. The evaluation showed that, although superiority over climatology was achieved, the forecasts (on most measures) proved to be inferior to the official forecasts. The system was then "scaled back", new knowledge added, and what has been termed VERSION 1 of the system was then evaluated over a 100-day trial, the results of which were presented to the 19th IIPS Conference (Stern, 2003) (http://www.weather-climate.com/internetforecasts.html). The deficiency evident with the PILOT VERSION appears to have been largely eliminated (especially for precipitation at day 1 and for temperature at days 1, 2, 3, 4 and 5).

On the basis of the results of the 100-day trial, further knowledge was added to the system and VERSION 2, which extends the outlook from 6 to 7 days, is now about to undergo a trial (http://www.weather-climate.com/internetforecasts2.html). This version provides a measure of uncertainty associated with the Numerical Weather Prediction (NWP) model output, uses cyclonicity in deriving the Probability of Precipitation (PoP) and the Quantitative Precipitation Forecasts (QPFs), and takes into account the sharp maximum temperature gradients associated with moderate ENE flow during summer.

The measure of uncertainty provided is "truer" than what would be achieved utilising conventional ensemble forecasting techniques, the measure being derived directly from an array of actual forecasts, rather than (as in conventional ensemble forecasting) from an array of model output generated by imposing a random set of perturbations on the initial analysis. Conventional ensemble forecasting suffers from the disadvantage of the level of uncertainty in the initial analysis being unknown, whereas the uncertainty associated with a data base of actual forecasts is known precisely.

It may be appropriate to ask, from a philosophical point of view, whether or not it may be premature, at this stage, to move towards computer replication of the manual forecast process. After all, the new National Digital Forecast Data Base (NDFD) of the U.S.A. National Weather Service (NWS) (Glahn & Ruth, 2003) allows for considerable manual involvement in its operation. A move to computer replication would result in a paradigm shift in the nature of the forecasting meteorologist's role. The role increasingly would become one of utilising sophisticated methodologies to analyse the output of the automated system, and implementing changes to it (consequent upon the analyses).

However, having the computer replicate various aspects of the manual forecast process, in order to make possible the production of a greatly increased number and variety of forecast products, is already happening. For example, the highly competitive environment that the New Zealand weather service finds itself has resulted in it moving down this pathway (Linton & Peters, 2003). Furthermore, there is pressure in the U.S.A. to allow commercial operators to take over government's traditional role in the provision of weather services (excepting the delivery of urgent warnings to protect life and property). To illustrate, AccuWeather's 31 January 2003 Media Release "expressed regret that the (National Research Council) report did not recommend that the National Weather Service end its practice of issuing routine weather forecasts."

Regardless of philosophy and outside of the legislative framework, competitive pressures may determine the future as private operators (and, also the general public) realise that the new technologies allow for the development and implementation of forecasting systems capable of providing a breadth of output far greater than one could ever hope to produce utilising the current approaches. As Brooks (1995), wrote: "technology, which initially allowed humans to make routine weather forecasts, will soon close that avenue of human endeavour ... (and thereby permit) concentration on severe events."

The talk will present an outline of the CFMIP and its relationship with other intercomparison projects. The experimental protocols and "in line" diagnostic requirements will be discussed. Examples will be given of some of the type of diagnostic output that will be produced to illustrate the strong connection between ISCCP and ERBE observations and model diagnosis.

Correlations between the Southern Oscillation Index (SOI) and the cyclone activity indices are calculated and analyzed. At a large scale, the W-E shift of the activity is well correlated with SOI, a few months before the season. At the New-Caledonia region scale, the correlation is still significant but not enough tu build a usable forecasting scheme. Correlations between the sea surface temperature (SST), El-Nino oceanic indices (NINO3, NINO4), quasi-biennal oscillation indice (QBO) and the cyclone activity indices are calculated and analyzed. The best correlations are obtained before the cyclone season. Various schemes using those indices are tested. The scheme using local SST, QBO indice and NINO4 is interesting. A forecast for the 2002/2003 season is presented and gives a usable information.

Gray parameter (SGP) and its dynamic part (DP) are calculated with NCEP re-analysis. DP gives better results then SGP. This approach doesn't bring any improvement as far as cyclone activity indices are concerned. Nevertheless it gives a geographical information consistent with El-Ni\~no and the general characteristic of the season. POAMA hindcasts are used to calculate the DP. Correlations with NCEP are significant and those forecast could be interesting to use as a complementary information to the statistical forecasts.

Verification results for the current sea surface temperature (SST) based seasonal forecasting system of the National Climate Centre will be presented. Use will be made of a range of scientifically sound verification procedures, which assess both the reliability of the issued forecasts and the predictability which is captured by the Pacific and Indian Ocean SST indices which drive the forecast model.

It will be shown that despite the relatively short period of forecasts available for verification, the Bureau forecasts have proved to be generally reliable and to have shown forecast skill which is consistent with expectations from hindcast validation and theory. Of the three seasonal forecast variables (maximum temperature, minimum temperature and rainfall) routinely forecast, the maximum temperature outlooks have been the most successful, rainfall forecast have almost everywhere performed with skill, while minimum temperature forecast have shown mixed success. The results will be summarized, and compared with the conclusion drawn from the recent seminar given by Garry Anderson of the University of Melbourne.

In this talk I compare simulations of the stand-alone Viterbo and Beljaars (VB95) land surface model with various soil and vegetation parameter sets against soil moisture and soil temperature observations across the Murrumbidgee River catchment in southeast Australia. The results indicate that the VB95 soil moisture is sensitive to the soil and, to a lesser degree, the vegetation parameters. VB95 can model the temporal fluctuations in soil moisture, and therefore the moisture fluxes, fairly realistically. However, the model exhibits a significant bias in the absolute soil moisture and a cool bias in the soil temperature over longer timescales. Surprisingly, the use of the best Australia-wide available soils and vegetation information did not improve VB95 significantly. Comparisons of model and observed soil moistures revealed that more realistic soil parameters are needed to reduce the model soil moisture bias. Given currently available soils parameters, any initialization of soil moisture with observed values would likely result in significant flux errors.

Analysis diagnostics suggest that the onset process may be associated with major cyclogenesis over high latitudes in the southwest Indian Ocean. The process that eventually affects the monsoon is an eastward and equatorward propagating wave train emanating from the high latitude cyclogenesis.

To test this hypothesis, idealised, dry simulations have been made using LAPS with periodic boundary conditions. Balanced, zonally-averaged initial states of (a) a baroclinically-unstable polar front jet at 40S, (b) a weak monsoon at 10S, and (c) a subtropical jet at 25S, are systematically introduced. Results indicate that high latitude cyclogenesis in the presence of a subtropical jet can influence the meridional location, zonal structure, vorticity and divergence of the monsoon. Similar to the analyses, the simulations show upper trough/ridge structures developing to very low latitudes. In accordance with theoretical studies, the subtropical jet seems to act as a duct for the eastward and equatorward propagation of wave trains into the tropics.

Comparison with previous studies, implications for tropical NWP, and planned future work will be briefly described.

Projected changes in tropical cyclone activity represents one of the greatest uncertainties in understanding the regional impacts of climate change. There are a number of reasons for this: a) The underlying theoretical explanation for why tropical cyclones occur is still not well understood. This is in contrast to mid-latitude highs and lows, that have been well explained by dynamical theories developed as early as the 1950's.

b) The single largest influence on tropical cyclone activity in the Australian region is the El Nino-Southern Oscillation phenomenon(or ENSO). The interannual variations in this system far outweigh any effect due to local sea surface temperatures or local air temperature. This complicates any projection of future tropical cyclone activity as there is still great uncertainty as to the behaviour of ENSO under a greenhouse climate.

c) Current regional projections for tropical cyclone activity are based on simulations using numerical General Circulation (GCM) models of the coupled atmosphere-ocean system. The key characteristic of a tropical cyclone is a intense inner core containing large horizontal gradients of wind speed and pressure. The horizontal scale of this inner core is much smaller than can be resolved using current GCM model technology.

d) In the current climate, tropical cyclone are more likely under certain large-scale conditions: for example they occur when the monsoon trough is located further south than usual. The probability of occurrence is increased when there is atmospheric tropical wave activity. The maximum intensity is limited according to how early the cyclone recurves which is governed by the latitude of the subtropical ridge and upper tropospheric subtropical jetstream. To date analysis of the output of climate change models has not methodically addressed the changes in these "synoptic triggers" for tropical cyclone formation.

Analysis of the tracks of tropical cyclones in our region over the past 40 years will be used to illustrate some of the above principles. We have constructed time series of a number of indices of cyclone activity in our region; and an analysis will be presented of the three-way associations between the cyclone indices, sea surface temperature and the SOI.

Global land cover at 1-km spatial resolution is coded according to multiple land cover schemes: IGBP; University of Maryland; LAI-FPAR Biome; Biome-BGC Biome; and Plant Functional Types. Classification uses a database of MODIS land products assembled each month and taken for one year of observation. A supervised classification algorithm uses decision trees with boosting to estimate anterior probabilities of membership for each pixel in each class, then utilizes prior probabilities from ancillary data and prior land cover products to find posterior probabilities and assign class labels to pixels. The training database includes more than 1500 global training site exemplars assembled using Landsat data and collateral information as available for local regions. Global accuracy is in the range of 75-80 percent for the IGBP classification.

The raw data sets and associated "index" (consisting of the set of Fourier coefficients and wavelet peaks) are large, so an interactive display tool has been written, allowing exploration with clickable spatial maps, time-series displays, EOFs, animations; by dataset, field, region, level, time period, wavelet period, significance, etc. The talk includes a set of interesting results so far, leavened by interpretive material, along with a software demo (software will be free to all within a year!).

To make this seminar more effective send all your MDT queries, questions, puzzles, problems to Robin Bowen, r.bowen@bom.gov.au, and he will pass them on to Hank for incorporation into the presentation. Please do this ASAP.

Note this will be an extended Wednesday morning seminar of at least one hour.

* This seminar does not necessarily reflect the views of any organizations

This seminar attempts to dry together input from two sources (Jan Polcher and the GLASS panel) and tries to describe the conceptual nature of the various types of component models used in NWP and climate models. The whole issue of what is observable and what is not will emerge. Soil moisture will be used as an example.

The implications of the answer to the question for model initialisation will be explored.

Since it is difficult to separate the contribution of various forcings to the observed trend in the SAM, a state-of-the-art global coupled model, the NCAR/DOE Parallel Climate Model, is utilised here to isolate the response of the climate system to individual external forcings. Ensembles of 20th Century simulations forced with the observed time series of greenhouse gases, tropospheric and stratospheric ozone, sulfate aerosols, volcanic aerosols, solar variability and various combinations of these are used to examine the SH trends in comparison to observations. Implications from future scenario runs are also discussed.