Progress in urban climatology over the two decades since the first publication of the International Journal of Climatology is reviewed. It is emphasized that urban climatology during this period has benefited from conceptual advances made in microclimatology and boundary-layer climatology in general. The role of scale, heterogeneity, dynamic source areas for turbulent fluxes and the complexity introduced by the roughness sublayer over the tall, rigid roughness elements of cities is described. The diversity of urban heat islands, depending on the medium sensed and the sensing technique, is explained. The review focuses on two areas within urban climatology. First, it assesses advances in the study of selected urban climatic processes relating to urban atmospheric turbulence (including surface roughness) and exchange processes for energy and water, at scales of consideration ranging from individual facets of the urban environment, through streets and city blocks to neighbourhoods. Second, it explores the literature on the urban temperature field. The state of knowledge about urban heat islands around 1980 is described and work since then is assessed in terms of similarities to and contrasts with that situation. Finally, the main advances are summarized and recommendations for urban climate work in the future are made. Copyright © 2003 Royal Meteorological Society.

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Two decades of urban climate research: a review of turbulence, exchanges of energy and water, and the urban heat island

https://researchweb.iiit.ac.in/~sai.deepak/lectures/14.%20Thermal%20remote%20sensing%20of%20urban%20climates%202003%20Voogt%20and%20Oke.pdf

Thermal remote sensing of urban climates

Urban greening to cool towns and cities: a systematic review of the empirical evidence.

The urban environment has distinctive biophysical features in relation to surrounding rural areas. These include an altered energy exchange creating an urban heat island, and changes to hydrology such as increased surface runoff of rainwater. Such changes are, in part, a result of the altered surface cover of the urban area. For example less vegetated surfaces lead to a decrease in evaporative cooling, whilst an increase in surface sealing results in increased surface runoff. Climate change will amplify these distinctive features. This paper explores the important role that the green infrastructure, i.e. the greenspace network, of a city can play in adapting for climate change. It uses the conurbation of Greater Manchester as a case study site. The paper presents output from energy exchange and hydrological models showing surface temperature and surface runoff in relation to the green infrastructure under current and future climate scenarios. The implications for an adaptation strategy to climate change in the urban environment are discussed.

Adapting cities for climate change: the role of the green infrastructure.

It has been 20 years since two seminal publications about ecosystem services came out: an edited book by Gretchen Daily and an article in Nature by a group of ecologists and economists on the value of the world’s ecosystem services. Both of these have been very highly cited and kicked off an explosion of research, policy, and applications of the idea, including the establishment of this journal. This article traces the history leading up to these publications and the subsequent debates, research, institutions, policies, on-the-ground actions, and controversies they triggered. It also explores what we have learned during this period about the key issues: from definitions to classification to valuation, from integrated modelling to public participation and communication, and the evolution of institutions and governance innovation. Finally, it provides recommendations for the future. In particular, it points to the weakness of the mainstream economic approaches to valuation, growth, and development. It concludes that the substantial contributions of ecosystem services to the sustainable wellbeing of humans and the rest of nature should be at the core of the fundamental change needed in economic theory and practice if we are to achieve a societal transformation to a sustainable and desirable future.

Twenty years of ecosystem services: How far have we come and how far do we still need to go?

The mean radiant temperature (Tmrt) is one of the most important meteorological parameters governing human energy balance. In this paper, three different methods of obtaining the Tmrt in an outdoor urban setting are compared. Method A is based on integral radiation measurements and angular factors, method B is based on measurements with a 38-mm flat grey globe thermometer and in method C makes use of the Rayman 1.2 software is used. Measurements were performed in a large open square in a high latitude city—Goteborg, Sweden—during clear to overcast weather conditions in October 2005 and in July and August 2006.

Results show that the difference between Method A and Method B was generally relatively small. Most of the discrepancy, caused by rapid changes in radiation, temperature and wind speed was smoothed out using 5 min mean values. By systematically and empirically changing the mean convection coefficient, the accuracy of Method B was improved and a new equation expressing the Tmrt was obtained. With this new equation the 38 mm flat grey globe thermometer could successfully be used to estimate the Tmrt in an outdoor urban setting provided that the wind speed and the air and globe temperatures are measured accurately. The study also shows that the flat grey colour of the globe thermometer slightly underestimates the level of short-wave radiation (i.e. sunshine). Method C works very well during the middle of the day in July, i.e. at high sun elevations. However, the model considerably underestimates the Tmrt in the morning and evening in July and during the whole day in October, i.e. at low sun elevations.

In outdoor urban settings where thermal comfort researchers or urban planners and designers require an easy and reliable method of estimating mean radiant temperature, the 38 mm flat grey globe thermometer provides a good and cheap solution. Copyright © 2007 Royal Meteorological Society

Different methods for estimating the mean radiant temperature in an outdoor urban setting

http://www.seedengr.com/The%20use%20of%20climate%20knowledge%20in%20urban%20planning.pdf

The use of climate knowledge in urban planning

This paper aims to provide a conceptual analysis of cultural ecosystem services and how they are linked to the concepts of landscape, heritage and identity. It discusses how these cultural ecosystem services can be assessed and integrated into spatial and physical planning. The paper presents two case studies to shed light on the assessment process. A case study from Sweden combines an analysis of ecosystem services with methods for documenting cultural heritage values in landscapes. A second case study from the Arafura–Timor Seas combines an analysis of cultural ecosystem services with methods for assessment of priority environmental concerns at the seascape scale. We demonstrate that the methods from cultural heritage conservation provide tools for the analysis of historical values as well as historical drivers of change in landscapes that can add time-depth to more spatially focused ecosystem assessments. We propose that methods for valuation of cultural heritage and identity in landscapes are integrated into assessments of ecosystem services to inform policy making and physical and spatial planning for sustainable management of ecosystems and landscapes. This could also provide an approach for bringing about integrated implementation of conventions and instruments from the environmental and cultural heritage fields, respectively.

Cultural ecosystem services provided by landscapes: Assessment of heritage values and identity

Subjective thermal comfort and outdoor activity in a park and a square in a satellite city northeast of Tokyo were investigated through structured interviews, observations, and comprehensive micrometeorological measurements. Results showed that the park was on an average 1.1°C cooler than the square. The relatively warmer thermal conditions in the square in comparison to the park resulted in a heat load of greater intensity for humans in the square. In general, there was a low relation between the thermal environment and the use of the two places in terms of total attendance. However, the use of the park was influenced more by the thermal conditions than by the use of the square, which can mainly be attributed to the different functions of the two places. Finally, examples of the differences between the use of the sun, the attitudes toward it, and outdoor exposure in Japan and Sweden are highlighted and discussed.

Ingegärd Eliasson

Papers

Different methods for estimating the mean radiant temperature in an outdoor urban setting

The use of climate knowledge in urban planning

Cultural ecosystem services provided by landscapes: Assessment of heritage values and identity

Thermal Comfort and Outdoor Activity in Japanese Urban Public Places

Urban nocturnal temperatures, street geometry and land use