Comparing microphysical/dynamical outputs by different cloud resolving models: impact on passive microwave precipitation retrieval from satellite

International audienceMesoscale cloud resolving models (CRM's) are often utilized to generate consistent descriptions of the microphysical structure of precipitating clouds, which are then used by physically-based algorithms for retrieving precipitation from satellite-borne microwave radiometers. However, in principle, the simulated upwelling brightness temperatures (TB's) and derived precipitation retrievals generated by means of different CRM's with different microphysical assumptions, may be significantly different even when the models simulate well the storm dynamical and rainfall characteristics. In this paper, we investigate this issue for two well-known models having different treatment of the bulk microphysics, i.e. the UW-NMS and the MM5. To this end, the models are used to simulate the same 24-26 November 2002 flood-producing storm over northern Italy. The model outputs that best reproduce the structure of the storm, as it was observed by the Advanced Microwave Scanning Radiometer (AMSR) onboard the EOS-Aqua satellite, have been used in order to compute the upwelling TB's. Then, these TB's have been utilized for retrieving the precipitation fields from the AMSR observations. Finally, these results are compared in order to provide an indication of the CRM-effect on precipitation retrieval

Imaging spectroscopy in the visible near infrared of the Aristarchus region on the Moon

In this article we present a study the Aristarchus region on the Moon by means of imaging spectroscopy data. We report the albedo, the UVVIS continuum and 0.9 - 1 mum absorption band maps, showing the complex pattern of Aristarchus crater ejecta and the distribution of surrounding materials. The extension of the dark mantling deposits present on the Aristarchus plateau is well shown from the data, appearing very red and with a uniform distribution of the 0.9 - 1 mum band. By using principal component analysis and clustering techniques the authors have identified seven different spectral regions. The plateau is composed of two distinct spectral units, while Aristarchus and its ejecta blanket show a complex distribution of both feldspatic and basaltic materials

On the potential of sub-mm passive MW observations from geostationary satellites to retrieve heavy precipitation over the Mediterranean Area

International audienceThe general interest in the potential use of the mm and sub-mm frequencies up to 425 GHz resolution from geostationary orbit is increasing due to the fact that the frequent time sampling and the comparable spatial resolution relative to the "classical" (?89 GHz) microwave frequencies would allow the monitoring of precipitating intense events for the assimilation of rain in now-casting weather prediction models. In this paper, we use the simulation of a heavy precipitating event in front of the coast of Crete island (Greece) performed by the University of Wisconsin - Non-hydrostatic Modeling System (UW-NMS) cloud resolving model in conjunction with a 3D-adjusted plane parallel radiative transfer model to simulate the upwelling brightness temperatures (TB's) at mm and sub-mm frequencies. To study the potential use of high frequencies, we first analyze the relationships of the simulated TB's with the microphysical properties of the UW-NMS simulated precipitating clouds, and then explore the capability of a Bayesian algorithm for the retrieval of surface rain rate, rain and ice water paths at such frequencies

ANALISA BIAYA PEMANFAATAN FLY ASH SEBAGAI MATERIAL DASAR BETON SELF COMPACTING GEOPOLYMER

The vibratory compaction process to obtain high-quality concrete has difficulties when faced with complex structural models. In the last few decades, research and development of self-compacting concrete (SCC) has been carried out. The application of SCC in Indonesia is still limited because the manufacturing costs are quite high. The composition of cement in SCC is more than conventional concrete, which means it causes higher air pollution. The amount of cement production is directly proportional to the amount of CO2 released into the atmosphere, so the world cement industry makes a major contribution to global greenhouse gas emissions. Several studies have begun to innovate combining SCC and overall cement replacement technology with a pozzolanic material that has cement-like characteristics. One of the alternative materials to replace Portland cement is fly ash, which is a waste material from burning coal in the PLTU. For fly ash to bind like cement, an activator is needed. The mixture of fly ash and activator is known as geopolymer paste, so the combination of these two concrete technologies is called geopolymer self-compacting concrete with fly ash as a base material. In Indonesia, geopolymer self-compacting concrete is still limited in the mix design testing phase, so the authors are interested in knowing the economic review of this type of concrete, and intend to analyze the cost of production of this geopolymer self-compacting concrete using local materials, fly ash from PLTU II Amurang, North Sulawesi Province. The study began with an examination of local materials in North Sulawesi for a concrete mix design. Followed by conducting experimental testing to get the characteristics of fresh concrete and the compressive strength of the concrete. Furthermore, analysis of production costs based on mix-design for 1 m3 of concrete. The workability test of the fresh geopolymer self-compacting concrete with fly ash as a base material through the slump flow method, V-funnel test, and L-Box Shaped test shows that it qualifies the SCC requirements and also produces K-250 quality of concrete. Geopolymer concrete combined with SCC concrete, which has a relatively high cost, results in high production costs of Geopolymer Self Compacting Concrete.Proses pemadatan dengan vibrasi untuk mendapatkan beton yang berkualitas memiliki kesulitan ketika diperhadapkan dengan model struktur yang kompleks. Sehingga beberapa dekade terakhir telah dilakukan penelitian dan pengembangan beton yang bisa memadat sendiri, yang dikenal dengan nama self-compacting concrete (SCC). Pengaplikasian SCC di Indonesia masih terbatas karena biaya pembuatannya yang cukup tinggi. Komposisi semen pada beton SCC lebih banyak dari beton konvensional yang artinya menimbulkan polusi udara lebih tinggi. Jumlah produksi semen berbanding lurus dengan jumlah CO2 yang dilepas ke atmosfer, maka industri semen dunia memberikan kontribusi besar terhadap emisi gas rumah kaca global. Beberapa penelitian mulai berinovasi mengkombinasikan SCC dan teknologi penggantian semen secara keseluruhan dengan material pozzolan yang memiliki karakteristik seperti semen. Salah satu alternatif material pengganti semen portland adalah fly ash yang merupakan material buangan pembakaran batu bara di PLTU. Agar Fly ash bisa mengikat seperti semen diperlukan aktivator. Campuran fly ash dan aktivator dikenal sebagai semen geopolimer, sehingga kombinasi dua teknologi beton ini disebut beton self compacting geopolymer dengan material dasar fly ash.  Di Indonesia, beton self compacting geopolymer masih terbatas dalam tahap pengujian mix design, sehingga penulis tertarik mengetahui tinjauan ekonomis beton jenis ini, dan bermaksud menganalisa biaya pembuatan beton self compacting geopolymer ini menggunakan material lokal, fly ash dari PLTU II Amurang, Sulawesi Utara. Penelitian dimulai dengan pemeriksaan material lokal di Sulawesi Utara untuk mencari mix-design beton. Dilanjutkan dengan melakukan pengujian experimental untuk mendapatkan karakteristik kelecakan beton segar dan kuat tekan beton. Selanjutnya dilakukan analisis biaya produksi berdasarkan mix-design per 1 m3 beton. Pengujian kelecakan dari pasta Beton Self Compacting Geopolymer dengan material dasar fly ash melalui metode slump flow,V-funnel test dan L-Box Shaped test menunjukkan bahwa sudah memenuhi syarat SCC juga menghasilkan beton mutu K-250. Beton geopolimer dikombinasikan dengan beton SCC yang biayanya memang sudah relatif tingi menghasilkan biaya pembuatan yang juga tinggi

ON THE RELIABILITY OF CURRENT MW-IR TECHNIQUES IN QUANTITATIVE PRECIPITATION MEASUREMENTS OVER MEDITERRANEAN BASIN

New satellite missions are near operational or in advanced planning stage: some of them are specifically devoted to the remote sensing of precipitation at space and time scales suitable for near-real-time applications. In this paper we address the capability of different sensors and sensors' combination in estimating precipitation in mediterranean area. Three events are analized in view of near-future sensors' availability (EGPM, GPM, MSG), to simulate the impact of these data on the real-time rain estimation. In particular we will focus our attention on combining the microwave signals coming from the visible/infrared with microwave rain estimates to evaluate the potentiality of new sensors on current algorithm. We analysed three cases occurred in Italy in the last years where reliable rainfall reference were available, discussing the critical impact of complex orography on the estimates

Low biocide emission antifouling based on a novel route of barnacle intoxication

Marine biofouling can be defined as the colonization of man-made surfaces in seawater by microscopic and macroscopic organisms. This phenomenon can result in great loss of function and effectiveness both for cruising ships and for static constructions. Of special concern are the negative effects of hard fouler such as barnacles, which cause increased drag resistance resulting in increases in fuel consumption, and disruption of the corrosion protective layer of marine vessels and constructions. Present biocide-based antifouling strategies are based on a continuous exposure of biocides at the film/water interface and consequently release into the environment if the antifouling efficacy is to be maintained. Such biocide-based solutions can therefore not be regarded as sustainable. The aim of this thesis is to describe the possibility to design biocide antifouling coatings based on a new strategy. Instead of releasing the bioactive molecule to the bulk water the biocide will be “entrapped” in the paint matrix and only after stimuli by organism interaction with the paint surface intoxication will take place. It was shown (Paper I) that using an experimental formulation, containing ivermectin, both in static panels and on boats, long lasting protection against barnacles was obtained. Moreover, using two model surfaces (Paper II), it was possible to separate and study the different contributions to the antifouling efficacy, finding that the low leaching of ivermectin had no contribution at all while surface’s modulus of the coating was the key factor. This supports the validity of the contact active antifouling hypothesis, rather than emission based. In (Paper III) we could follow the fate of barnacle growing on ivermectin containing coatings, and both field and laboratory tests could demonstrate that the intoxication of barnacles start when the juvenile organism reach ca. 0.6-0.7mm in diameter. Electronic microscopy images on the panels after the test, demonstrate that on control paint (no biocide) the juvenile barnacles (0.6-0.7mm diameter) already leaves imprint or penetration marks on the rosin based coatings. The distribution of ivermectin in the dry film seemed to be related with enhancement of barnacles contact intoxication. This was studied by fluorescence microscopy in (Paper I) and by the use ToF-SIMS in (Paper IV). This particular analytic method gives the possibility to follow organic biocides in paint film without the need of labelling or modify the biocide molecule in any extent. The entrapped antifouling strategy opens up the possibility to achieve long term antifouling (>10 years) as there is no need to use erosive binders. Moreover, this system might also find it uses in marine constructions and other fields where maintenance is difficult