EXPERIMENTAL STUDY OF THE ROLE OF INITIAL AND BOUNDARY CONDITIONS IN MESOSCALE NUMERICAL WEATHER PREDICTION

~~EXPERIMENTAL STUDY OF THE ROLE OF INITIAL AND BOUNDARY CONDITIONS IN MESOSCALE NUMERICAL WEATHER PREDICTION@闫敬华$Guangzhou Institute of Tropical & Marine Meteorology, CMA, Guangzhou 510080 China @Detlev Majewski$Duetscher Wetterdinst, Offenbach, Germany~~National Project "973" (Research on Heavy Rain in China) and BMBF of Germany (WTZ- Project CHN01/106)…     

Screening of Microalgae for Feasible Mass Production in Industrial Hypersaline Wastewater Using Disposable Bioreactors

Ten algae species were analyzed by comparing their growth in specific hypersaline industrial wastewater. It was a by‐product of fertilizer production which was released by K + S Aktiengesellschaft, Germany. Due to processing, brine water contains a high amount of salts ( 200 g L^?1). A successful algal biotechnology mainly depends on choosing and screening the adequate algae for a specific application along with the design of optimal culture conditions with comparable photo bioreactor technologies. Therefore, a high throughput screening technology was developed. In comparison to glass flasks or flat panel reactors this system was eligible for screening applications because of disposable characteristics and the equability of each culture tube. Dunaliella salina, Tetraselmis tetrathele, and Nannochloropsis salina grew in the presence of hypersaline wastewater where T. tetrathele grew best to a wastewater concentration of 75% by salt shock experiments. D. salina tolerates a wastewater level up to 80% by gradual increase. Intracellular ion contents of lyophilized algae samples were measured. They feature special transporter to either exclude ions, i.e., sodium from the cell, or to include ions like potassium and magnesium in order to secure functionality of sensitive enzymes. Under saline stress conditions these transport systems as well as metabolic pathways leading to the production of compatible osmolytes could be induced. Stress tolerance mechanisms developed in initially unstressed culture either by stepwise adaptation or by shock exposure to harsh salt condition. For this reason a feasible mass production in industrial hypersaline wastewater was possible.     

Preliminary Sunyaev–Zel'dovich observations of galaxy clusters with OCRA-p

We present 30-GHz Sunyaev–Zel'dovich (SZ) observations of a sample of four galaxy clusters with a prototype of the One Centimetre Receiver Array (OCRA-p) which is mounted on the Torun 32-m telescope. The clusters (Cl 0016+16, MS 0451.6–0305, MS 1054.4–0321 and Abell 2218) are popular SZ targets and serve as commissioning observations. All four are detected with clear significance  (4 –6σ)  and values for the central temperature decrement are in good agreement with measurements reported in the literature. We believe that systematic effects are successfully suppressed by our observing strategy. The relatively short integration times required to obtain these results demonstrate the power of OCRA-p and its successors for future SZ studies.     

Performance of the veto detector incorporated into the ZEPLIN-III experiment

The ZEPLIN-III experiment is operating in its second phase at the Boulby Underground Laboratory in search of dark matter WIMPs. The major upgrades to the instrument over its first science run include lower background photomultiplier tubes and installation of a plastic scintillator veto system. Performance results from the veto detector using calibration and science data in its first six months of operation in coincidence with ZEPLIN-III are presented. With fully automated operation and calibration, the veto system has maintained high stability and achieves near unity live time relative to ZEPLIN-III. Calibrations with a neutron source demonstrate a rejection of 60% of neutron-induced nuclear recoils in ZEPLIN-III that might otherwise be misidentified as WIMPs. This tagging efficiency reduces the expected untagged nuclear recoil background from neutrons during science data taking to a very low rate of ?0.2 events per year in the WIMP acceptance region. Additionally, the veto detector provides rejection of 28% of γ-ray induced background events, allowing the sampling of the dominant source of background in ZEPLIN-III - multiple scatter γ-rays with rare topologies. Since WIMPs will not be tagged by the veto detector, and tags due to γ-rays and neutrons are separable, this population of multiple scatter events may be characterised without biasing the analysis of candidate WIMP signals in the data.     

Evidence of probable paleotsunami deposits on Kho Khao Island, Phang Nga Province, Thailand

The 2004 tsunami deposits and probable paleotsunami deposits were studied at the southern Kho Khao Island, on Andaman Sea coast of Thailand. The 2004 tsunami laid down about 8?cm of fining upward medium sand and locally about 40?cm of massive coarse sand with common mud clasts. The sediments were characterized by the presence of marine foraminiferal assemblage; however, already after 5?years many of carbonate foraminiferal tests were partly or completely dissolved. The probable paleotsunami deposits form layer about 1?m thick. It consists of massive very coarse sand with common big shells and mud clasts. Its composition suggests a marine origin and the presence of mud clasts, and similarity to the 2004 tsunami deposits suggests that the layer was left by paleotsunami, which took place probably during the late Holocene, even though two shells within the layer gave ¹⁴C ages of 40,000?years or more.     

Field pond as a sink for nutrients migrating from agrocenoses to freshwaters

Nutrients migrating from agrocenoses through drainage effluents are retained in a field pond. Studies were carried out concerning the effectiveness of this process in an aquatic environment in the conditions of development of phytoplankton and submersed and floating-leaved macrophytes (1987), in the state of phytoplankton dominance (1988), and, in a swamp environment, in the state of dominance of emergent macrophytes (1991).The greatest effectiveness of this process was found in the conditions of development of aquatic plants, i.e. submersed and folating-leaved macrophytes and phytoplankton. In the warm season of 1987 the retention of nutrients (in g · m^–2) was: TN — 7.20, TP — 3.5, K — 3.80, Ca — 119, and Mg — 8.2. When the euglenoid phytoplankton dominated, the level of retention was slightly higher and the export of N_org was also noted (3.27 g · m^–2 season^–1). In the case of dominance of emergent macrophytes, a reduction in the TN load, particularly in N-NO₃ (by 3.67 m^–2 season^–1), occurred, though at the same time a release of P, K, and Mg was noted. The export exceeded the import of TP by 0.44, K by 15.3, and Mg by 1.4 g · m^–1. The conditions for the functioning of a field pond as a sink for nutrients migrating from agroecosystems to surface waters were determined.     

S diffusivity in Fe–Ni–S–P melts

Soret diffusion rise times were observed and resolved for Fe–Ni–S–P melts at 10 kbar in thermal gradients between 1300 and 1450°C. A steady-state separation of S-rich components to the hot end of the 2 mm long liquid charges is achieved in about 20 minutes. Chemical diffusivities of about 10⁻⁵ cm²/s are consistent with these observations and those of the compaction velocity of aggregates of crystalline Fe metal against the cold end of our experiments. These rapid diffusivities are not rapid enough for diffusion to be an important agent of bulk mass transfer in the addition or extraction of light elements in the Earth's core.     

The (sub)Structure of the Halo

The fossil record of the Milky Way indicates an evolution including periodic accretions of smaller galaxies and clusters, consistent with hierarchical models of galaxy formation. I discuss three observational programs that demonstrate that the phase space distribution of stars, clusters and dwarf galaxies in the Galactic halo contains degrees of substructure left by the débris of tidally disrupted stellar systems. This revised version was published online in July 2006 with corrections to the Cover Date.     

Operational regional prediction

Summary Regional operational prediction requires the development, implementation and steady improvement of a modelling system which comprises different components like the data assimilation scheme, numerical forecast model, postprocessing and application modules as well as packages for monitoring, diagnostics and verification. The text highlights the impact of some of those components like lateral boundary conditions, data assimilation and statistical postprocessing on the quality of operational regional prediction systems and proposes some important research directions for an improvement of the systems from the operational point of view.With 14 Figures