Ground-based GNSS for climate research: review and perspectives

In climate research, the role of water vapour can hardly be overestimated. Water vapour is the most important natural greenhouse gas and is responsible for the largest known feedback mechanism for amplifying climate change. It also strongly influences atmospheric dynamics and the hydrologic cycle through surface evaporation, latent heat transport and diabatic heating, and is, in particular, a source of clouds and precipitation.Atmospheric water vapour is highly variable, both in space and in time. Therefore, measuring it remains a demanding and challenging task. The Zenith Total Delay (ZTD) estimated from GNSS observations, provided at a temporal resolution of minutes and under all weather conditions, can be converted to Integrated Water Vapour (IWV), if additional meteorological variables are available. Inconsistencies introduced into long-term time series from improved GNSS processing algorithms, instrumental, and environmental changes at GNSS stations make climate trend analyses challenging. Ongoing re-processing efforts using state-of-the-art models aim at providing consistent time series of tropospheric data, using 24+ years of GNSS observations from global and regional networks. GNSS is reaching the “maturity age” of 30 years when climate normal of ZTD/IWV (and horizontal gradients) can be derived. Being not assimilated in numerical weather prediction model reanalyses, GNSS products can also be used as independent datasets to validate climate model outputs (ZTD/IWV). However, what is the actual use of GNSS ZTDs in climate monitoring? What are the advantages of using GNSS ZTDs for climate monitoring? In addition, what would be the best ZTD time series to serve the climate community?The presentation will provide a review of the progress made in and the status of using GNSS tropospheric datasets for climate research, highlighting the challenges and pitfalls, and outlining the major remaining steps ahead. We will show examples demonstrating the benefits for climate monitoring brought by using GNSS ZTD and/or IWV datasets in complement to other observations.This contribution is related to the activities of JWG C.2: Quality control methods for climate applications of geodetic tropospheric parameters, https://iccc.iag-aig.org/joint-work-groups/216, of the IAG Inter-Commission Committee on "Geodesy for Climate Research" (ICCC)

Tropospheric Products from High-Level GNSS Processing in Latin America

ARTÍCULO PUBLICADO EN REVISTA EXTERNA. The present geodetic reference frame in Latin America and the Caribbean is given by a network of about 400 continuously operating GNSS stations. These stations are routinely processed by ten Analysis Centres following the guidelines and standards set up by the International Earth Rotation and Reference Systems Service (IERS) and International GNSS Service (IGS). The Analysis Centres estimate daily and weekly station positions and station zenith tropospheric path delays (ZTD) with an hourly sampling rate. This contribution presents some attempts aiming at combining the individual ZTD estimations to generate consistent troposphere solutions over the entire region and to provide reliable time series of troposphere parameters, to be used as a reference. The study covers ZTD and IWV series for a time-span of 5 years (2014–2018). In addition to the combination of the individual solutions, some advances based on the precise point positioning technique using BNC software (BKG NTRIP Client) and Bernese GNSS Software V.5.2 are presented. Results are validated using the IGS ZTD products and radiosonde IWV data. The agreement was evaluated in terms of mean bias and rms of the ZTD differences w.r.t IGS products (mean bias 1.5 mm and mean rms 6.8 mm) and w.r.t ZTD from radiosonde data (mean bias 2 mm and mean rms 7.5 mm). IWV differences w.r.t radiosonde IWV data (mean bias 0.41 kg/m2 and mean rms 3.5 kg/m2).Sitio de la revista: https://link.springer.com/chapter/10.1007/1345_2020_12

Participatory transport planning the experience of eight european metropolitan regions

This chapter presents experience with participatory transport planning in eight European metropolitan regions: Ljubljana, Oslo, Gothenburg, Helsinki, Budapest, Rome, Porto and Barcelona. These metropolitan regions answered the questionnaire on strengths, weaknesses and needs and an in-depth questionnaire on participatory transport planning. The results were presented at a workshop, where representatives from these eight metropolitan regions shared their experience in two workshop sessions, one dealing with the key stakeholders in participatory transport planning and the other dealing with ways to get them involved. The findings show that stakeholder involvement differs between the local and regional levels. Participants engagement is greater at the local level, where measures are more concrete and less abstract. The participatory planning process takes longer than the traditional planning processes, but it can ease the implementation of the project/measure to the extent that it justifies the additional resources and time. It is of crucial importance to include all the relevant stakeholders, to provide an experienced facilitator and, above all, to include the results in the final plans and policies. Although there are differences in the participatory planning culture between the countries and regions involved, the use of participatory methods in transport planning is becoming increasingly important. Document type: Part of book or chapter of boo

Towards sustainable urban development: the social acceptability of high-rise buildings in a Ghanaian city

Over the years, many city managers, policy makers and academics alike have turned to high-rise buildings as pathway to sustainable urban development. However, the sustainability of such types of development in various geographical contexts, especially in sub-Saharan Africa, is a subject less explored. Amidst the promotion of high-rise development in a rapidly urbanizing metropolis in Ghana, Kumasi, the research empirically examined the social acceptability of high-rise residential facilities and the institutional capacity for their effective management. By conducting face-to-face interviews with sampled households, and critical public service providers in the metropolis, the study uncovered that, contrary to the evidence from many Asian cities, there is generally low social acceptability of high-rise developments, and a weak institutional capacity for effective service delivery. The research concludes that, whilst it is tempting to embrace high-rise buildings as sustainable development pathway, it is crucial they are pursued with much circumspection. In addition to their design being tailored to the local needs of the people for whom they are built, the promotion of high-rise development should recognize the importance of effective service delivery, and general social acceptability

The application of ‘elite interviewing’ methodology in transdisciplinary research: A record of process and lessons learned during a 3-year pilot in urban planetary health research

This paper sets out the rationale and process for the interviewing methodology utilized during a 3-year research pilot, ‘Moving Health Upstream in Urban Development’ (UPSTREAM). The project had two primary aims: firstly, to attempt to value economically the health cost benefits associated with the quality of urban environments and secondly, to engage with those in control of urban development in the UK in order to determine what are the barriers to and opportunities for creating healthy urban environments, including those identified through the utilisation of economic valuation. Engagement at senior level with those who have most control over key facets of planning and development implementation—such as land disposal, investment, development delivery and planning permission—was central to the approach, which encompassed the adoption of ‘elite interviewing’, a method developed in the USA in the 1950s and used in the political sciences but relatively unutilized in the health and environmental sciences [1]. Two rounds of semi-structured interviews were undertaken with 15 senior decision-makers from the UK’s main urban development delivery agencies, both public and private. The ‘elite interviewing’ approach successfully enabled the UPSTREAM project to capture and analyse the information received from the interviewees, all of whom held influential or leadership posts in organisations that are important actors in the process of planning, developing and constructing the built environment in the UK. Having academic and practitioner research leads on an equal footing created some minor tensions, but it also appeared to strengthen the rigor of the approach through a broad knowledge of context ‘in-house’. This form of co-production at times challenged academic traditions in qualitative analysis, but it also appeared to build trust with interviewees and provided greater clarity of the real-world context under investigation. Findings from this study are written up in a separate paper