On the water and energy cycles in the Tropics

The water and energy cycles are major elements of the Earth climate. These cycles are especially active in the intertropical belt where satellites provide the most suitable observational platform. The history of Earth observations of the water cycle and of the radiation budget viewed from space reveals that the fundamental questions from the early times are still relevant for today's research. The last 2 decades have seen a number of milestones regarding the documentation of rainfall, mesoscale convective systems (MCS), water vapour and radiation at the top of the atmosphere (TOA). Beyond dedicated missions that provided enhanced characterizations of some elements of the atmospheric water cycle and field campaigns that allowed the gathering of validation data, the advent of the long record of meteorological satellites lead to new questioning on the homogenisation of the data time series, etc. The use of this record to document the tropical climate brought new results of the distribution of humidity and reinforced the understanding of some robust features of the African monsoon. Challenges for the immediate future concerns the deepening of the understanding of the role of cloud systems in the monsoon circulation, the downscaling of the documentation of the water and energy cycle at the scale of these cloud systems, the research of better adequation between the users and the satellite estimate of rainfall and finally a much needed methodological effort to build exploitable time series for the estimation of climatic trends in the water and energy cycle in the Tropics. The required observations to address these challenges are rapidly presented with emphasis on the upcoming Megha-Tropiques (MT) mission.     

The Kwakshua Watersheds Observatory,central coast of British Columbia,Canada

The Kwakshua Watersheds Observatory (KWO) is an integrative watersheds observatory on the coastal margin of a rain-dominated bog-forest landscape in British Columbia (BC), Canada. Established in 2013, the goal of the KWO is to understand and model the flux of terrestrial materials from land to sea – the origins, pathways, processes and ecosystem consequences – in the context of long-term environmental change. The KWO consists of seven gauged watersheds and a network of observation sites spanning from land to sea and along drainage gradients within catchments. Time-series datasets include year-round measurements of weather, soil hydrology, streamflow, aquatic biogeochemistry, microbial ecology and nearshore oceanographic conditions. Sensor measurements are recorded every 5 min and water samples are collected approximately monthly. Additional observations are made during high-flow conditions. We used remote sensing to map watershed terrain, drainage networks, soils and terrestrial ecosystems. The watersheds range in size from 3.2 to 12.8 km², with varying catchment characteristics that influence hydrological and biogeochemical responses. Despite local variation, the overall study area is a global hotspot for yields of dissolved organic carbon, dissolved organic nitrogen and dissolved iron at the coastal margin. This observatory helps fill an important gap in the global network of observatories, in terms of spatial location (central coast of BC), climate (temperate oceanic), hydrology (very high runoff, pluvial regime), geology (igneous intrusive, glacially scoured), vegetation (bog rainforest) and soils (large stores of organic carbon).     

In-situ high-temperature Raman spectroscopic studies of aluminosilicate liquids

We have measured in-situ Raman spectra of aluminosilicate glasses and liquids with albite (NaAlSi₃ O₈) and anorthite (CaAl₂Si₂O₈) compositions at high temperatures, through their glass transition range up to 1700 and 2000 K, respectively. For these experiments, we have used a wire-loop heating device coupled with micro-Raman spectroscopy, in order to achieve effective spatial filtering of the extraneous thermal radiation. A major concern in this work is the development of methodology for reliably extracting the first and second order contributions to the Raman scattering spectra of aluminosilicate glasses and liquids from the high temperature experimental data, and analyzing these in terms of vibrational (anharmonic) and configurational changes. The changes in the first order Raman spectra with temperature are subtle. The principal low frequency band remains nearly constant with increasing temperature, indicating little change in the T-O-T angle, and that the angle bending vibration is quite harmonic. This is in contrast to vitreous SiO₂, studied previously. Above Tg, intensity changes in the 560–590 cm^?1 regions of both sets of spectra indicate configurational changes in the supercooled liquids, associated with formation of additional Al-O-Al linkages, or 3-membered (Al, Si)-containing rings. Additional intensity at 800 cm^?1 reflects also some rearrangement of the Si-O-Al network.     

Comparison between chironomid-inferred July temperatures and meteorological data AD 1850–2001 from varved Lake Silvaplana,Switzerland

Inferred temperatures from chironomids preserved in the varved sediment of Lake Silvaplana in the Eastern Swiss Alps were compared with instrumental data obtained from a meteorological station in Sils-Maria, on the shore of Lake Silvaplana, for the time interval 1850–2001. At near-annual resolution, the general patterns of chironomid-inferred temperature changes followed the meteorological record over the last ∼150 years (r _Pearson = 0.65, P = 0.01) and 87% of the inferences had deviations from the instrumental data below the root-mean-square error of prediction (RMSEP). When the inferences were compared with a 2-year running mean in the meteorological data, 94% of the inferences had differences with the instrumental data below the RMSEP, indicating that more than half of the inaccurate inferences may have been due to errors in varve counting. Larger deviations from the instrumental data were also obtained from samples with low percentages of fossil taxa represented in the training set used for temperature reconstruction and/or assemblages with poor fit to temperature. Changes in total phosphorus (TP, as inferred by diatoms) and/or greater precipitation were possible factors affecting the accuracy of the temperature reconstruction. Although these factors might affect the quantitative estimates, obtaining >80% accurate temperature inferences suggests that chironomid analysis is a reliable tool for reconstructing mean July air temperature quantitatively over the last ∼150 years in Lake Silvaplana.     

Review of Ray Theory Applications in Modelling and Imaging of Seismic Data

Throughout the last twenty years, 3D seismic ray modelling has developed from a research tool to a more operational tool that has gained growing interest in the petroleum industry. Various areas of application have been established and new ones are under development. Many of these applications require a modelling system with flexible, robust and efficient modelling algorithms in the core. The present paper reviews the basic elements of such a system, based on the open model concept and the wavefront construction technique. In the latter, ervený's dynamic ray tracing is an intrinsic part. The modelling system can be used for generating ray attributes and synthetic seismograms for realistic 3D surveys with tens of thousands of shots and receivers. Moreover, some other types of application areas are illustrated: Production of Green's functions for prestack depth migration and hybrid modelling (combined ray and finite-difference modelling), attribute mapping and illumination analysis, both for survey planning and interpretation. Finally, the concepts of isochron rays and velocity rays related to seismic isochrons have been introduced recently, with very interesting future applications.     

Interferometric calibrations and astronomical calibrators

This chapter gives some indications on the selection of suitable astronomical calibrators for interferometric observations. After an introduction to interferometric calibrations, we will focus on the criteria, steps and tools developed by ESO to prepare VLTI observations and to select calibrators. Although the tools described here are focused on VLTI, the problem of astronomical calibrators is the same for the other interferometers and can be approached in the same way.     

Inclusive approaches to urban climate adaptation planning and implementation in the Global South

As cities increasingly engage in climate adaptation planning, many are seeking to promote public participation and facilitate the engagement of different civil society actors. Still, the variations that exist among participatory approaches and the merits and tradeoffs associated with each are not well understood. This article examines the experiences of Quito (Ecuador) and Surat (India) to assess how civil society actors contribute to adaptation planning and implementation. The results showcase two distinct approaches to public engagement. The first emphasizes participation of experts, affected communities, and a wide array of citizens to sustain broadly inclusive programmes that incorporate local needs and concerns into adaptation processes and outcomes. The second approach focuses on building targeted partnerships between key government, private, and civil society actors to institutionalize robust decision-making structures, enhance abilities to raise funds, and increase means to directly engage with local community and international actors. A critical analysis of these approaches suggests more inclusive planning processes correspond to higher climate equity and justice outcomes in the short term, but the results also indicate that an emphasis on building dedicated multi-sector governance institutions may enhance long-term programme stability, while ensuring that diverse civil society actors have an ongoing voice in climate adaptation planning and implementation.

Policy relevance

Many local governments in the Global South experience severe capacity and resource constraints. Cities are often required to devolve large-scale planning and decision-making responsibilities, such as those critical to climate adaptation, to different civil society actors. As a result, there needs to be more rigorous assessments of how civil society participation contributes to the adaptation policy and planning process and what local social, political, and economic factors dictate the way cities select different approaches to public engagement. Also, since social equity and justice are key indicators for determining the effectiveness and sustainability of adaptation interventions, urban adaptation plans and policies must also be designed according to local institutional strengths and civic capacities in order to account for the needs of the poor and most vulnerable. Inclusivity, therefore, is critical for ensuring equitable planning processes and just adaptation outcomes.     

Assessing green gentrification in historically disenfranchised neighborhoods: a longitudinal and spatial analysis of Barcelona

To date, little is known about the extent to which the creation of municipal green spaces over an entire city addresses social or racial inequalities in the distribution of environmental amenities – or whether such an agenda creates contributes to green gentrification. In this study, we evaluate the effects of creating 18 green spaces in socially vulnerable neighborhoods of Barcelona during the 1990s and early 2000s. We examined the evolution over time of six socio-demographic gentrification indicators in the areas close to green spaces in comparison with the entire districts. Our results indicate that new parks in the old town and formerly industrialized neighborhoods seem to have experienced green gentrification. In contrast, most economically depressed areas and working-class neighborhoods with less desirable housing stock and more isolated from the city center gained vulnerable residents as they became greener, indicating a possible redistribution and greater concentration of vulnerable residents through the city.     

Automatic Detection and Classification of Coronal Holes and Filaments Based on EUV and Magnetogram Observations of the Solar Disk

A new method for the automated detection of coronal holes and filaments on the solar disk is presented. The starting point is coronal images taken by the Extreme Ultraviolet Telescope on the Solar and Heliospheric Observatory (SOHO/EIT) in the Fe ix/x 171 Å, Fe xii 195 Å, and He ii 304 Å extreme ultraviolet (EUV) lines and the corresponding full-disk magnetograms from the Michelson Doppler Imager (SOHO/MDI) from different phases of the solar cycle. The images are processed to enhance their contrast and to enable the automatic detection of the two candidate features, which are visually indistinguishable in these images. Comparisons are made with existing databases, such as the He i 10830 Å NSO/Kitt Peak coronal-hole maps and the Solar Feature Catalog (SFC) from the European Grid of Solar Observations (EGSO), to discriminate between the two features. By mapping the features onto the corresponding magnetograms, distinct magnetic signatures are then derived. Coronal holes are found to have a skewed distribution of magnetic-field intensities, with values often reaching 100?–?200 gauss, and a relative magnetic-flux imbalance. Filaments, in contrast, have a symmetric distribution of field intensity values around zero, have smaller magnetic-field intensity than coronal holes, and lie along a magnetic-field reversal line. The identification of candidate features from the processed images and the determination of their distinct magnetic signatures are then combined to achieve the automated detection of coronal holes and filaments from EUV images of the solar disk. Application of this technique to all three wavelengths does not yield identical results. Furthermore, the best agreement among all three wavelengths and NSO/Kitt Peak coronal-hole maps occurs during the declining phase of solar activity. The He ii data mostly fail to yield the location of filaments at solar minimum and provide only a subset at the declining phase or peak of the solar cycle. However, the Fe ix/x 171 Å and Fe xii 195 Å data yield a larger number of filaments than the Hα data of the SFC.     

The influence of sunspot canopies on magnetic inclination measurements in solar plages

Sunspots are known to have large, low-lying magnetic canopies, i.e. horizontal magnetic fields overlying a field-free medium, that cover substantial fractions of active region plage. In this paper we consider the influence of such canopies on the inclination of plage magnetic fields. We find that for observations in spectral lines like 5250.2Å the neglect of a sunspot canopy when determining magnetic inclination angles of plage fields can introduce errors exceeding 5–10°. This is particularly true if the observations do not have high spatial resolution. Thus this effect may explain some of the measurements of substantially inclined fields in solar plages. Furthermore we find that the Fe I 15648 Å line is far superior in giving correct flux-tube inclinations in the presence of a sunspot magnetic canopy. Finally, the inversion of full Stokes profiles is shown to produce more reliable results than results obtained by considering only ratios of individual Stokes profile parameters.