A citizen centred urban network for weather and air quality in Australian schools.

High-quality, standardized urban canopy layer observations are a worldwide necessity for urban climate and air quality research and monitoring. The Schools Weather and Air Quality (SWAQ) network was developed and distributed across the Greater Sydney region with a view to establish a citizen-centred network for investigation of the intra-urban heterogeneity and inter-parameter dependency of all major urban climate and air quality metrics. The network comprises a matrix of eleven automatic weather stations, nested with a web of six automatic air quality stations, stretched across 2779 km2, with average spacing of 10.2 km. Six meteorological parameters and six air pollutants are recorded. The network has a focus on Sydney's western suburbs of rapid urbanization, but also extends to many eastern coastal sites where there are gaps in existing regulatory networks. Observations and metadata are available from September 2019 and undergo routine quality control, quality assurance and publication. Metadata, original datasets and quality-controlled datasets are open-source and available for extended academic and non-academic use.

Dynamic thermal pleasure in outdoor environments - temporal alliesthesia.

Thermal comfort research has been historically centred around the concept of "thermal neutrality". Thermal neutrality originates from the steady-state indoor environment and is increasingly questioned when used to define the optimum sensation in outdoor environments. This calls for new criteria, designated for non-steady state and dynamically evolving outdoor settings. To address this need, we investigated thermal pleasure dynamics in outdoor environments based on thermal alliesthesia - a psychophysiological framework for understanding the hedonic responses elicited by non-steady-state thermal exposures. Detailed field studies were conducted in Sydney, Australia, during a 30-day period covering both summer and winter with a total of 35 subjects. The thermal sensation scale was quantitatively divided into four alliesthesial potential areas - two with moderate and two with strong alliesthesial potential - based on their divergence to the preferred sensation. We find that the temporal pleasure change (dP) can be predicted using thermal sensation change (dT). The results showed that linear regression performed strongly (R2 = 0.77 for summer and R2 = 0.79 for winter) in predicting dP when subjects' preceding sensation was in the strong alliesthesial potential zones - namely the 'Hot' and 'Cold' areas. When subjects' prior thermal sensation fell in the thermoneutral zone with moderate alliesthesial potential, a quadratic fit against dT provides a more reasonable prediction of dP (R2 = 0.61 for summer and R2 = 0.56 for winter). The dynamic thermal pleasure models provide a more nuanced subjective interpretation of outdoor urban spaces that includes thermal pleasure and delight. This study contributes further empirical support to the thermal alliesthesia framework and extends its application scope into outdoor thermal comfort research.

Climate change and thermal comfort in Hong Kong.

Thermal comfort is a major issue in cities and it is expected to change in the future due to the changing climate. The objective of this paper is to use the universal thermal comfort index (UTCI) to compare the outdoor thermal comfort in Hong Kong in the past (1971-2000) and the future (2046-2065 and 2081-2100). The future climate of Hong Kong was determined by the general circulation model (GCM) simulations of future climate scenarios (A1B and B1) established by the Intergovernmental Panel on Climate Change (IPCC). Three GCMs were chosen, GISS-ER, GFDL-CM2.1 and MRI-CGCM2.3.2, based on their performance in simulating past climate. Through a statistical downscaling procedure, the future climatic variables were transferred to the local scale. The UTCI is calculated by four predicted climate variables: air temperature, wind speed, relative humidity and solar radiation. After a normalisation procedure, future UTCI profiles for the urban area of Hong Kong were created. Comparing the past UTCI (calculated by observation data) and future UTCI, all three GCMs predicted that the future climate scenarios have a higher mode and a higher maximum value. There is a shift from 'No Thermal Stress' toward 'Moderate Heat Stress' and 'Strong Heat Stress' during the period 2046-2065, becoming more severe for the later period (2081-2100). Comparing the two scenarios, B1 exhibited similar projections in the two time periods whereas for A1B there was a significant difference, with both the mode and maximum increasing by 2°C from 2046-2065 to 2081-2100.

A synoptic climatology of pollen concentrations during the six warmest months in Sydney, Australia.

This paper takes an air mass approach to investigating the influence of weather on pollen concentrations in the atmosphere in Sydney, Australia, by producing a synoptic classification of pollen concentrations measured in the Sydney Basin. This synoptic classification has been produced using multivariate statistical techniques including principal component analysis and cluster analysis, to assign days into meteorologically homogenous categories. Surface and upper air meteorological data for warm months (October-March) over a 10-year period were used as input into the statistical analyses. Eleven synoptic categories were found in Sydney during the warm months. Pollen concentrations for the total pollen load and five individual families measured over a 3.5-year period have been investigated for each of the synoptic categories. High pollen concentrations during the warm months in Sydney are found to be influenced by the presence of a region of low surface pressure located to the south of the continent, bringing fast dry westerly gradient winds to Sydney. It is envisaged that these results will be important from a pollen forecast and associated public health perspective.