Search

Surface meltwater is becoming increasingly widespread on Antarctic ice shelves. It is stored within surface ponds and streams, or within firn pore spaces, which may saturate to form slush. Slush can reduce firn air content, increasing an ice-shelf's vulnerability to break-up. To date, no study has mapped the changing extent of slush across ice shelves. Here, we use Google Earth Engine and Landsat 8 images from six ice shelves to generate training classes using a k-means clustering algorithm, which are used to train a random forest classifier to identify both slush and ponded water. Validation using expert elicitation gives accuracies of 84% and 82% for the ponded water and slush classes, respectively. Errors result from subjectivity in identifying the ponded water/slush boundary, and from inclusion of cloud and shadows. We apply our classifier to the Roi Baudouin Ice Shelf for the entire 2013–20 Landsat 8 record. On average, 64% of all surface meltwater is classified as slush and 36% as ponded water. Total meltwater areal extent is greatest between late January and mid-February. This highlights the importance of mapping slush when studying surface meltwater on ice shelves. Future research will apply the classifier across all Antarctic ice shelves.

Many of the glaciers in the Nepalese Himalaya are partially covered in a layer of loose rock known as debris cover. In the Dudh Koshi River Basin, Nepal, approximately 25% of glaciers are debris‐covered. Debris‐covered glaciers have been shown to have a substantial impact on near‐surface meteorological variables and the surface energy balance, in comparison to clean‐ice glaciers. The Weather Research and Forecasting (WRF) model is often used for high‐resolution weather and climate modelling, however representation of debris‐covered glaciers is not included in the standard land cover and soil categories. Here we include a simple representation of thick debris‐covered glaciers in the WRF model, and investigate the impact on the near‐surface atmosphere over the Dudh Koshi River Basin for July 2013. Inclusion of this new category is found to improve the model representation of near‐surface temperature and relative humidity, in comparison with a simulation using the default category of clean‐ice glaciers, when compared to observations. The addition of the new debris‐cover category in the model warms the near‐surface air over the debris‐covered portion of the glacier, and the wind continues further up the valley, compared to the simulation using clean‐ice. This has consequent effects on water vapour and column‐integrated total water path, over both the portions of the glacier with and without debris cover. Correctly simulating meteorological variables such as these is vital for accurate precipitation forecasts over glacierized regions, and therefore estimating future glacier melt and river runoff in the Himalaya. These results highlight the need for debris cover to be included in high‐resolution regional climate models over debris‐covered glaciers.

Understanding the local valley wind regimes in the Hindu‐Kush Karakoram Himalaya is vital for future predictions of the glacio‐hydro‐meteorological system. Here the Weather Research and Forecasting model is employed at a resolution of 1 km to investigate the forces driving the local valley wind regime in a river basin in the Nepalese Himalaya, during July 2013 and January 2014. Comparing with observations shows that the model represents the diurnal cycle of the winds well, with strong daytime up‐valley winds and weak nighttime winds in both months. A momentum budget analysis of the model output shows that in the summer run the physical drivers of the near‐surface valley wind also have a clear diurnal cycle, and are dominated by the pressure gradient, advection, and turbulent vertical mixing, as well as a non‐physical numerical diffusion term. By contrast, the drivers in the winter run have a less consistent diurnal cycle. In both months, the pressure gradient, advection, numerical diffusion and Coriolis terms dominate up to 5000 m above the ground. The drivers are extremely variable over the valley, and also influenced by the presence of glaciers. When glaciers are removed from the model in the summer run, the wind continues further up the valley, indicating how the local valley winds might respond to future glacier shrinkage. The spatial variability of the drivers over both months is consistent with the complex topography in the basin, which must therefore be well represented in weather and regional climate models to generate accurate outputs.

It is pleasing to see that there has been recent interest in Sydney modernism from a number of prominent Sydney cultural institutions. The origins of modernism can be traced back to the 1880s, while Sydney modernism has be identified from the early years of the 20th century to the 1960s.

One of the icons of the local area that has long disappeared was the car museum and picnic ground know as Greens Motorcade Museum Park at Leppington on the Old Hume Highway.

The story of European settlement in the Cowpastures is intimately connected to the story of the convicts and their masters. This story has not been told and there is little understanding of the role of the convicts in the Cowpastures district before 1840. Who were they? What did they do? Did they stay in the district? The convicts that ended up the in Cowpastures district were part of the 160,000 who were transported to the Australian colonies from England, Wales, Ireland and the British colonies. The convicts were a form of forced labour, with a global history that goes back to Roman times. Amongst those who were landed were human souls who were part of the dark story of banishment and exile.

The Domain and Royal Botanic Gardens are some of the most important open spaces in Australia's urban landscape. The 29 hectares of gardens are surrounded by 51 hectares of parkland including the Sydney Domain. They were officially recognised as a botanic garden in 1816, while only becoming 'Royal' in 1959. The site is one of the world's oldest colonial botanic gardens and one of the most important botanical gardens in the Southern Hemisphere (only Rio de Janeiro is older).

On January 26, 1788 a group of sailing ships unloaded their human flotsam and jetsam in Sydney Cove. Amongst those who were landed were souls who were part of the dark story of banishment and exile that dates back to Roman times. The foundation of the Australian nation was just one part of a global story of forced human suffering that is still going on today.

Catherine Fields once boasted a national tourist facility which attracted thousands of visitors a year to the local area, the El Caballo Blanco entertainment complex. The El Caballo Blanco complex opened in April 1979 at Catherine Fields. The main attraction was a theatrical horse show presented with Andalusian horses, which was held daily in the large 800-seat indoor arena.

The paper examines a series of land releases by land developer Neil McLean on his farm St Elmo at Campbelltown between 1949 and 1961, which eventually formed a concentric ring around the old town centre. McLean was prescient in his understanding of the needs of Sydney's growth well before the Cumberland County Council designated Campbelltown as a satellite city in 1960. His vision and foresight put into action what the founders of the county plan envisaged as part of Sydney's metropolitan rural-urban fringe well before it happened on the city's urban frontier.

ln 20l6 Circular Quay Railway Station turned 60 years old. On its opening the railway station was an expression of Sydney's modernity with many features of Sydney modernism including Art Deco decorative ornamentation of grilles and bronze aquatic animal motifs placed near stairways and doorways. The station had a modern design with clean lines on the floor and ceiling, wrought iron balustrading on the walls, and escalators.

The Australian Red Cross Society is part of one of the world's most important humanitarian organisations. It has provided relief in times of crisis for 100 years. The International Red Cross and Red Crescent movement has seven guiding principles: humanity, impartiality, neutrality, independence, voluntary service, unity and universality. The origins of the movement are located in mid-nineteenth century Europe; now it comprises around 190 national societies, including Australia's, which was founded in 1914. This year marked a global first for Australia ‒ it held an inaugural conference, Histories of the Red Cross Movement: Continuity and Change, for historians, archivists, curators and others interested in exploring historical ideas and contexts within the Red Cross Movement. An increasing number of historians has taken an interest in the Red Cross since the International Committee of the Red Cross and International Federation of Red Cross and Red Crescent (IFRC) societies opened their archives in the 1990s.

'Get to know your neighbourhood - you could be in for some surprises!' says PHA member Katherine Knight, after picking up one of the volumes in the Kingsclear Books Pictorial History Series. A number of PHA members, including myself, have written for Kingsclear about particular localities, regions or local government areas. My contribution to this ongoing project was to write the text for Camden and District.