Seminars - Melbourne
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To schedule a CAWCR seminar, contact the
seminar coordinators with the details and the proposed date.
Here are details of how to access the shared calendar in Outlook (internal use only) to view available seminar time slots.
CAWCR SEMINARS 2015
The venue is the seminar room (Floor 9, east side) at 700 Collins Street, Docklands
Seminars are run typically with duration
of 30 to 45 minutes + questions. Dates and times are shown. If you are a vistor to the Bureau, you need to register at reception in the foyer.
For further details contact the
Wednesday 27th May, 10:00am - 11:00am, Conference/Meeting Rooms, 9th floor east, 700 Collins St
Verification of Forecast Guidance from the Forecast Demonstration Project
Thursday 21th May, 10:00am - 11:00am, Conference/Meeting Rooms, 9th floor east, 700 Collins St
Wednesday 13th May, 10:00am - 11:00am, Conference/Meeting Rooms, 9th floor east, 700 Collins St
Update on stratospheric ozone depletion: an environmental success story
David Karoly, Robyn Schofield and Julie Arblaster
UniMelb and BoM
Since the discovery of the Antarctic ozone hole in the 1980s, extensive research has shown that manufactured chemicals, such as chlorofluorocarbons (CFCs), are the cause of ozone depletion in the upper atmosphere. The ozone layer, which sits in the stratosphere approximately 10-30 km above the Earth’s surface, has been depleted by more than 50% over Antarctica compared to 1980 levels and is not projected to recover to those levels until the mid-late 21st Century. Ozone depletion is not only of concern because it protects us from the harmful effects of ultraviolet radiation. In the past decade, research has also established a connection between ozone depletion and climate changes seen in summer in the Southern Hemisphere over the past 30-50 years. This presentation will provide an overview of the latest WMO/UNEP Scientific Assessment of Ozone Depletion (http://www.wmo.int/pages/prog/arep/gaw/ozone_2014/ozone_asst_report.html
), including highlights from the composition, ozone observations, ozone chemistry and climate sections.
Friday 8th May, 2:00pm - 3:00pm, Conference/Meeting Rooms, 9th floor east, 700 Collins St
Evolution of the International Argo program
Wednesday 29th April, 10:00am - 11:00am, Conference/Meeting Rooms, 9th floor east, 700 Collins St
Friday 24th April, 10:00am - 11:00am, Conference/Meeting Rooms, 9th floor east, 700 Collins St
Parameterizing gravity waves in models
Australian Antarctic Division
The extension of model lids upward into the stratosphere and mesosphere has brought with it both advantages and challenges. Among the challenges is a need for more sophisticated parameterizations of small scale waves (AKA 'gravity waves'). In particular, the addition of waves forced by processes other than orography (such as by convection or frontal systems) extends the waves parameter space and opens a wide variety of parameterization options that are difficult to constrain physically.
In this talk, I will discuss the motivation behind making changes to the model lid height in the context of southern hemisphere processes, summarize key aspects of gravity wave parameterization and review the strategies being adopted by modelling groups around the world. Some emphasis will be given to work being done at the National Center for Atmospheric Research on their Whole Atmosphere Community Climate Model (WACCM).
Thursday 09th April, 10:00am - 11:00am, Conference/Meeting Rooms, 9th floor east, 700 Collins St
Effects of topography on tropical cyclone tracks
Professor Johnny Chan
City University of Hong Kong
As a tropical cyclone (TC) moves closer to land with substantial topography, interaction between the TC circulation and the topography can cause changes in the TC track. This talk will summarise our work in the recent few years on the physical processes that cause such changes and the sensitivities of such changes to the initial latitude, size and background flow of the TC.
Wednesday 25th March, 11:00am - 11:45am, Conference/Meeting Rooms, 9th floor east, 700 Collins St
Update on Met Office’s recent model developments and system implementation
UK Met Office
The upgrades made to the global modelling system in PS34 (June 2014) and to the Limited Area Models in PS35 (February 2015) comprise the biggest changes made to the Met Office’s Unified Model systems in the last 10 years, including the implementation of the new dynamical core ENDGame.
This seminar will outline these changes and benefits, and present other aspects of Unified Model system development from convective scale to earth system application, model performance, tropical convection, and a future look to the next generation dynamical core and associated software infrastructure. Recent developments towards the next Global Coupled configuration (GC3) that will be the foundation of the future Met Office’s seamless suite of coupled operational systems will be presented.
Finally, as the UM Partnership has entered a mature phase, there is scope to jointly develop some new science capability in key areas identified as joint priorities.
Wednesday 25th March, 10:00am - 10:45am, Conference/Meeting Rooms, 9th floor east, 700 Collins St
Recent developments in the UM Technical Infrastructure Programme
UK Met Office
The Partner Technical Infrastructure Programme focuses on delivering capabilities that resolve priority weaknesses of the UM Infrastructure rather than ongoing maintenance. The medium term goal is a more streamlined system that is more flexible, easier to use and easier to adopt for both Research and Production requirements.
This presentation will summarise some of the achievements to-date, planned collaborative work in 2015/16 and identify benefits that when fully realised, will fulfil the Programme vision.
More information about the Technical Infrastructure Programme can be found in Trac pages contained within the Met Office Science Repository Service https://code.metoffice.gov.uk/trac/TI/wiki
Wednesday 18th March, 10:00am - 11:00am, Conference/Meeting Rooms, 9th floor east, 700 Collins St
Internal tools for accessing Bureau Australian climate data for research - present and future
This talk will give researchers an overview of tools available on the Bureau's internal network for accessing climate data and seeks suggestions for features that would be most useful to them in the new Climate Data Explorer.
The Bureau of Meteorology's Climate and Oceans Data and Analysis Section (CODAS) is responsible for publishing the Bureau's climate record. A national team provides data to external clients, servicing over 11,000 emails and a similar number of phone calls per year. The tools used to extract data for external clients are available on the Bureau intranet. This talk will cover those that should be of most relevance for research - The Climate Zone (TCZ) for extracting station observations from the ADAM database; the database of observing stations information SitesDB; Climate Data Online (CDO) for accessing basic daily and monthly climate data; and several other internal tools for accessing marine data, bulk extraction of data from ADAM, and model data extraction.
CODAS also develops new tools for accessing the data both internally and externally. The team is working at making more of the climate record and advanced data types available for direct access through an expanded CDO website. This will include more of the ADAM database, spatial data such as AWAP and specialised data streams like wave and tidal records. It is envisaged that the Climate Data Explorer (CDE) will allow users to select subsets of data fields, visualise data and perform some data analysis, and download data in user-preferred formats. User requirements and technical specifications of the service are currently being developed. The internal research community is seen as important stakeholders in CDE, so feedback on current plans and suggestions for useful features of CDE are being sought.
Wednesday 06th May, 10:00am - 11:30am, Conference/Meeting Rooms, 9th floor east, 700 Collins St
Thursday 12th March, 2:00pm - 3:00pm, Conference/Meeting Rooms, 9th floor east, 700 Collins St
Dynamics of the Tornado Vortex
University of Miami (USA)
In the first part of this talk, I will review the basic mechanisms for all tornado-like vortices (tornadoes, waterspouts, and dust devils). Our current understanding of what controls their intensity, structure, and dynamics comes from both laboratory experiments and numerical simulations. In particular, the "thermodynamic speed limit" sets a fairly low upper limit on the maximum mean wind speeds compared to the levels of damage that are found in the most extreme events.
The most extreme wind speeds are associated with asymmetric, coherent structures such as "multiple vortices" that are often visible in photographs and videos. A new analysis of the multiple vortex phenomenon will be presented using much more realistic representations of the tornado-vortex flow than had been used in some earlier studies. The linearized stability analysis successfully predicts the dominant structures in unsteady, three-dimensional simulations. In addition, symmetric modes are identified that may explain symmetric oscillations that have been directly observed in real tornadoes.
Wednesday 11th March, 10:00am - 11:00am, Conference/Meeting Rooms, 9th floor east, 700 Collins St
Biases and limitations in the estimation of tropical cyclone intensity
University of Miami (USA)
While the average errors of tropical cyclone track forecasts have been steadily declining over the last two decades, intensity forecasts have only marginally improved. For North Atlantic forecasts, the 24-hour intensity forecast has shown no improvement, with mean errors of peak wind speed forecasts remaining around 10 knots for the last 20 years. Some recent studies have suggested that, given the current "observing system"
of satellites, aircraft reconnaissance, and subjective analysis, the actual peak wind speed cannot be measured to an accuracy greater than about 10 knots. In this study, we use an Observing System Simulation Experiment (OSSE) approach to test the limitations of even nearly perfect observing systems to capture the peak wind speed occurring within a tropical storm or hurricane. The data set is provided by a 1-km resolution simulation of an Atlantic hurricane with surface wind speeds saved every 10 seconds. An optimal observing system consisting of a dense field of fixed anemometers is placed in the path of the storm: this provides a perfect measurement of the peak 1-minute wind speed. In reality, reliable surface observations are very rare in tropical cyclones. Therefore suboptimal observing systems consisting of a small number of anemometers are sampled and compared to the truth provided by the optimal observing system. Results show that a single, perfect anemometer experiencing a direct hit by the right side of the eyewall will still underestimate the actual peak intensity by 10-20%. Even an unusually large number of anemometers (e.g., 3-5) experiencing direct hits by the storm will together underestimate the peak wind speeds by 5-10%. However, the peak intensity of just one or two anemometers will provide, on average, a good estimate of the true peak intensity averaged over several hours, which is in fact more consistent with operational definitions of intensity. If the mean bias were known perfectly for each case, it could be used to correct the wind speeds, leaving only mean absolute errors of 3-5%.
Thursday 05th March, 10:00am - 11:00am, Conference Room 3, 6th floor, 700 Collins St
Hadley Centre Extremes Datasets: HadISD and HadEX2
Robert Dunn and Kate Willett
Met Office Hadley Centre (UK)
HadISD is an integrated station dataset from the Met Office Hadley Centre. It contains over 6000 stations covering the 1973-2014 period, and is planned to be updated annually. Near-surface temperature, dewpoint and sea-level pressure data, along with cloud cover, wind speed and direction have been quality controlled using an automated suite of tests. These tests address many known issues with observational data from individual surface-stations, and have been combined with buddy checks against neighbouring stations in an objective, reproducible and consistent manner.
I will describe our ongoing development and use of this dataset, touching on our assessment of its homogeneity, plans for HadISD version 2 and our communication plan with users; as well as highlighting a number of scientific applications, ranging from individual extreme events to animal welfare.
A complementary dataset, HadEX2, has been developed in collaboration with CCRC-UNSW. This is a dataset of gridded temperature and precipitation extremes indices from 1901-2010. I will outline an assessment we carried out of the structural and parametric uncertainties of this dataset, which showed that the global trends are on the whole robust to choices in the methods used in creating HadEX2.
I’m a Climate Monitoring scientist at the Met Office Hadley Centre and I’d like to give you an overview of my work.
My main job is the development of a global surface humidity monitoring product. This has recently been completed for land only and is now freely available. Development has involved a lengthy process of quality control, conversion across variables, homogenisation, uncertainty estimation and gridding. We’ve recently been able to begin analysis to try and understand how the world is getting warmer and wetter (in terms of water vapour), but drier, relatively. Comparison with global climate models shows considerable disagreement for the recent historical record.
My other job involves trying to improve the world of surface temperature data to meet the needs of 21st Century climate science. The International Surface Temperature Initiative has released its first version databank of monthly land surface temperature data. This is the largest archive of freely available monthly land meteorological data with version control and traceability to source where possible. I lead the ISTI’s benchmarking working group. We are busy trying to synthetically replicate the 32000+ stations so that we can benchmark test our climate data processing methods.
Finally, there is the annual State of the Climate report to be done. I coordinate the global climate chapter. We assess a wide array of Essential Climate Variables each year, in the context of the historical record. The signal of climate change is clear from the deep oceans to the top of the atmosphere.
Wednesday 27th February, 10:00am - 11:00am, Conference/Meeting Rooms, 9th floor east, 700 Collins St
Seasonal forecasting, and climate analyses, of thunderstorms and associated impacts
The potential for seasonal forecasting of thunderstorms has not previously been examined for any region of the world. Convective available potential energy (CAPE), as an indicator of conditions favourable to thunderstorm formation, is found to be significantly related to the El Niñouthern Oscillation (ENSO) on seasonal time scales throughout many regions of the world. This indicates the potential to produce seasonal forecasts of thunderstorms (and perhaps associated impacts such as heavy rainfall, hail, strong winds, tornados, lightning and fires). The relationship between thunderstorm activity (based on satellite lightning data) and ENSO shows strong similarities to the relationship between CAPE and ENSO in terms of its seasonal and spatial variability throughout the world. Maps are presented of anomalous thunderstorm activity for different phases of ENSO (El NiñNeutral and La Niñfor each season of the year. In addition to ENSO, a number of other large-scale modes of atmospheric and oceanic variability are examined in relation to thunderstorm occurrence, with ENSO having the strongest relationship with thunderstorm activity for all cases examined.
Lightning is a significant ignition source for a large proportion of the area burnt by fires throughout the world. The strong relationships between thunderstorm activity and large-scale atmospheric modes of variability suggests the possibility of developing a coarse-scale method for indicating the risk of lightning occurrence (i.e. coarse in spatial and temporal scales, suitable for application to global climate models). A range of atmospheric variables associated with thunderstorm occurrence are examined (based on reanalyses) in relation to global lightning stroke data obtained from a network of ground-based sensors. Rainfall data (from TRMM) are used to categorise the lightning as 'dry' or 'wet' based on the amount of rainfall accompanying the lightning. A discussion of the interactions between lightning and fire occurrence is presented.
Wednesday 11th February, 10:00am - 11:00am, Conference/Meeting Rooms, 9th floor east, 700 Collins St
The role of coastal associated rainfall in the tropics
Areas that are particularly poorly represented in GCMs are the tropical coastal regions. Therefore this study develops and applies an algorithm to objectively identify coast line affected precipitation. Pattern-recognition techniques are applied to the data to determine the occurrence and intensity of coastline-affected rainfall features. The effects of changing parameters in the algorithm are investigated. Having identified precipitation associated with coastlines, its climatological features and diurnal behaviour are studied. We find that a significant percentage of rainfall in tropical and sub-tropical coastal areas results from coastline effects. Furthermore the results suggest that major modes of climate variability, such as the Madden-Julia-Oscillation and the El Niñouthern Oscillation have a strong effect on the existence of coastal precipitation features. We also identify large-scale variables favouring coastal precipitation and find that the large-scale state for detected rainfall differs from from the large-scale state for non-detected rainfall.
Wednesday 4th February, 10:00am - 11:00am, Conference/Meeting Rooms, 9th floor east, 700 Collins St
New Climate Change Projections for Australia -- Overview and Key Messages
Bertrand Timbal and Aurel Moise
The CSIRO and Bureau of Meteorology have updated information about observed climate variability in Australia and projected changes over the 21st century. The projections are based on up to 40 of the latest climate model simulations, with confidence ratings for different variables, consistent with methods used by the Intergovernmental Panel on Climate Change (IPCC). This supersedes information released by CSIRO and the Bureau of Meteorology in 2007. Emphasis has been placed on providing projections data and information for use in planning and risk assessment within the natural resource management (NRM) sector. This research was funded by the Department of the Environment through the Planning for Climate Change Fund and is supported by co-funding from CSIRO and the Bureau of Meteorology. Four IPCC scenarios of greenhouse gas and aerosol emissions have been considered. The lower scenarios assume significant reductions in emissions, and lead to slower rates of climate change. The higher scenarios lead to faster climate change, and a greater range of possibilities for variables such as temperature, rainfall and sea level. This talk will present an overview of the project outcomes and key messages.
Thursday 22nd January, 11:15am - 12:15pm, Conference/Meeting Rooms, 9th floor east, 700 Collins St
Heavy rainfall over Pakistan and northwest India: Influence of modulation of the large-scale circulation over the Indo-Pacific region
Indian Institute of Tropical Meteorology
This study investigates the role of large-scale circulation shifts, induced by
Indo-Pacific Sea Surface Temperature (SST) patterns, during heavy summer
monsoon rainfall of 2010 over Indo-Pak region. The evolution of monsoon
synoptic systems and mid-latitude atmospheric blocking associated with the
heavy precipitation and floods over northwest Pakistan during strong La Nina
event of 2010 has been investigated by several past studies. The anomalous westward
shift of west-Pacific sub-tropical high, suppression of convection over Bay of
Bengal and anomalous northward moisture transport from Arabian Sea inspired us
to diagnose the role of remote and regional SST boundary forcings on the
modulation of large-scale circulation over Indo-Pacific region.
The realistic response of observed SSTs in simulating 2010 Indo-Pak heavy
rainfall anomalies, using a high resolution Atmospheric General Circulation
Model, developed at the Laboratoire de Meteorologie Dynamique (LMDZ4; Z stands
for zoom; from France), is intriguing. This realistic simulation response
encouraged us to diagnose the distinct roles of Indian Ocean and Pacific SST
anomalies by conducting additional simulation experiments using ENSO-related
and ENSO-unrelated forcings.
A PDF copy of all the presented seminars can be found at the "Find Seminar Presentation Documents..." link at the top of the page (available to BoM staff only). Seminars for previous years can be found at the "Goto list of BMRC seminars for ..." site at the top of the page. In addition, a list of actual videos from some previous seminars is held in the library and 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. Note: as of 2005, it is standard practice for all seminars to be recorded as wmv movies,
with the permission of the presenter.
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 CAWCR Seminar Coordinator"