Retrieval of tropospheric water vapour from airborne far-infrared measurements: a case study

We describe studies undertaken in support of the Far-infrared Outgoing Radiation Understanding and Monitoring (FORUM) mission, ESA’s ninth Earth Explorer, designed to investigate whether airborne observations of far-infrared radiances can provide beneficial information on mid and upper tropospheric water vapour concentrations.Initially we perform a joint temperature and water vapour retrieval and show that the water vapour retrieval exploiting far-infrared measurements from the Tropospheric Airborne Fourier Transform Spectrometer (TAFTS) shows improvement over the a-priori Unified Model global forecast when compared to in situ dropsonde measurements. For this case the improvement is particularly noticeable in the mid-upper troposphere. Equivalent retrievals using mid-infrared radiances measured by the Airborne Research Interferometer Evaluation System (ARIES) show much reduced performance, with the degrees of freedom for signal (DFS), reduced by a factor of almost 2. Further sensitivity studies show that this advantage is decreased, but still present when the spectral resolution of the TAFTS measurements is reduced to match that of ARIES.The beneficial role of the far infrared for this case is further confirmed by performing water vapour only retrievals using ARIES and TAFTS individually, and then in combination. We find that the combined retrieval has a DFS value of 6.7 for water vapour, marginally larger than that obtained for the TAFTS retrieval and almost twice as large as that obtained for ARIES.These results provide observational support of theoretical studies highlighting the potential improvement that far-infrared observations could bring for the retrieval of tropospheric water vapour

Spatio-temporal evolution of long-range transported mineral desert dust properties over rural and urban sites in Central Europe

An exceptionally strong and very fast (120h) mineral dust inflow from North Africa to Poland was predicted by NMMB/BSC-Dust and NAAPS models on 10–11 June 2019. Simultaneous measurements with two complex lidar systems at the EARLINET-ACTRIS urban site in Warsaw (Central Poland) and the PolWET peatland site in Rzecin (Western Poland) captured the evolution of this dust event. The advected air masses had different source areas in North Africa, they were reaching each station via independent pathways, and thus, were unlikely mixed with each other. The excellent capabilities of the next generation PollyXT lidar and the mobile EMORAL lidar allowed for the derivation of full datasets of aerosol optical properties profiles that enabled comparative study of the advected dust properties evolution. Within a mere 350 km distance between Warsaw and Rzecin, distinctly different dust properties were measured, respectively: dry mineral dust composed mainly of coarse mode dust particles (50 ± 5 % of the total particle backscattering profile) versus the wet mineral dust dominated by fine dust particles (58 ± 4 %). A new parameter fine-to-coarse dust ratio (FCDR) is proposed to describe more intuitively mineral dust composition

Introduction: Political representation in France and Germany

This book is about political representation in France and Germany. It explores and compares what French and German Members of Parliament (MPs) think about representation and their roles as representatives, how they organize their interactions with the electorate at the district level and how citizens perceive and assess the quality of the representation process in these two large West European democracies. These issues deserve scholarly interest for several reasons. The questions as to whether, to what degree and in what respect the elected MPs perceive themselves as representatives of the political community, and what a “good representative” should look like in the eyes of the citizens, are at the core of normative theories of representative democracy. However, as already shown in Hanna Pitkin’s (1967) pioneering work, representation is not an uncontested concept, and questions concerning the quality of representation have not only been addressed by many works on theories of democracy, but have also received attention in a plethora of empirical research

Citizens and Representatives in France and Germany

CITOYENS ET PARLEMENTAIRES EN ALLEMAGNE ET EN FRANC