12,333 research outputs found
Development Of SCIAMACHY Operational ESA Level 2 Products Towards Version 5 And Beyond
No full textSince the foundation of the SCIAMACHY Quality Working Group (SQWG) in a joint ESA-DLR-NIVR inter-agency effort in late 2006, the ESA operational Level 2 processor was significantly improved w.r.t. data quality and product range. During the last two years the product list was substantially enhanced by new (total columns of SO2, BrO, OClO, H2O, CO, Limb BrO profiles, Limb cloud flags) and improved products (total columns of O3, NO2, Absorbing Aerosol Index, Limb O3 profiles, Limb NO2 profiles).
For example, important improvements were achieved in the O3 and NO2 profile calculation by implementing an upgraded retrieval scheme and using now Level 1b version 7.0 data with an improved pointing correction. Nadir products of total column O3 and Absorbing Aerosol Index were improved by applying a radiometric degradation correction (m-factors) in the Level 1 to 2 processing step
First validation of SCIAMACHY BrO columns
No full textRetrievals of BrO columns using version 5.01 of the SCIAMACHY NRT processor as well as independent non-operational algorithms are compared with GOME and with ground-based measurements from two Arctic stations. NRT BrO columns are found to agree with GOME and non-operational data sets to within 20% for moderate and large slant columns, while for slant columns smaller than 1.5×1014 molec/cm2, the NRT product reports larger values by 20 to 100%. First comparisons with ground-based measurements in Harestua (60°N) and Ny-Alesund (79°), tentatively evaluated at the time of the SCIAMACHY overpasses, provide encouraging results although more work is still needed for a detailed quantitative validation of BrO
BrO profiling from ground-based doas observations: New tool for the ENVISAT/SCIAMACHY validation
No full textTime-series of BrO vertical profiles and corresponding total columns retrieved from ground-based zenith-sky DOAS observations at Harestua (60°N, 10°E) are compared to ENVISAT/SCIAMACHY limb and nadir and GOME scientific products. Retrieval algorithms from the following groups are involved in the comparison exercise: IUP-Bremen, IUP-Heidelberg, and Harvard Smithsonian Center for Astrophysics for SCIAMACHY limb BrO profiles, BIRA-IASB and IUP-Bremen for SCIAMACHY nadir BrO total columns, and BIRA-IASB for GOME BrO total columns. Comparisons between ground-based UV-visible and SCIAMACHY and GOME data cover the 2002-2004 period and are performed in the same photochemical conditions since the BIRA-IASB profiling algorithm includes a stacked box photochemical model, enabling the retrieval of BrO profiles at any solar zenith angle
Retrieval of BrO columns from SCIAMACHY and their validation using ground-based DOAS measurements
No full textBuilding on the experience acquired with ERS-2/GOME, a scientific algorithm has been developed at BIRA-IASB for the retrieval of total BrO columns from SCIAMACHY nadir measurements. In order to overcome problems related to anomalies in the polarization response of the SCIAMACHY instrument, specific BrO retrieval settings have been introduced, different from those used for the retrieval of GOME data. In the present study, we focus first on an assessment of the accuracy of the SCIAMACHY slant column retrieval, through various sensitivity tests and comparisons with coincident measurements from GOME. Second, SCIAMACHY nadir BrO results are compared with independent correlative measurements of BrO columns resolved into their stratospheric and tropospheric contributions, and photochemically matched to satellite observations. Correlative data are derived from DOAS observations performed by IASB-BIRA at three locations (Harestua 60°N, OHP 44°N, and Reunion Island 22°S). From the combined analysis of GOME, SCIAMACHY and ground-based and balloon-borne DOAS observations the overall consistency of the remote-sensing BrO observing system is evaluated and discussed in light of recent findings published in the literature. In particular our results strengthen the existence of a worldwide background of BrO located in the free-troposphere with mixing-ratios in the range from 1-2 pptv
Total and tropospheric BrO derived from GOME and SCIAMACHY as part of the temis project
No full textBromine monoxide plays an important role in the chemistry of the polar atmosphere because of its high efficiency as a catalyst of the ozone destruction in both the stratosphere and the troposphere. In the polar boundary layer, large cyclic emissions are observed every year at spring (the so-called "bromine explosion" phenomenon), which are responsible for the occurrence of fast and efficient tropospheric ozone destruction events. Total columns of BrO have been monitored by the GOME instrument onboard the ESA ERS-2 satellite since 1995. Since July 2002, similar observations can be obtained with SCIAMACHY on the ENVISAT platform. In the present contribution, analyses for total and tropospheric BrO columns derived from both instruments are described, with a focus on the assessment of their mutual consistency. Attempts to extract quantitative estimates of the tropospheric BrO contents over polar and mid-latitude regions are presented, using an algorithm that combines GOME measurements with SLIMCAT 3D chemical transport calculations. Key aspects of the tropospheric BrO retrieval and current sources of uncertainties are discussed
Tropospheric and stratospheric BrO and NO2 columns derived by use of satellite observations and 3D CTM FinROSE
No full textTotal slant column densities (SCD) of NO2 and BrO from the GOME ERS-2 satellite nadir measurements have been split into stratospheric and tropospheric loadings. In order to obtain tropospheric vertical column densities (VCD) two key challenges arise: the quantification of the stratospheric column and the calculation of the tropospheric air mass factor (AMF). Stratospheric NO2 and BrO columns are derived at the instrument's overpass time by means of a stratospheric chemistry transport model, i.e. FinROSE-etm, to take into account the stratospheric variability of these trace gases. In order to gain the trace gas tropospheric column the stratospheric slant column is subtracted from the DOAS slant column retrieval
A new species of Aleurolobus Quaintance et Baker (Homoptera, Aleyrodidae) from Southern Europe.
No full textAleurolobus teucrii n. sp. is described from southern Italy and the Maltese Islands (Central Mediterranean). The species seems to be monophagous on Teucrium fruticans L. A key to the European species of this genus (A. niloticus Priesner et Hosny, A. olivinus (Silvestri), A. wunni (Ryberg) and A. teucrii n. sp.) is provided.peer-reviewe
FIGURE 9 in The first fossil Dufoureillini (Hemiptera: Heteroptera: Anthocoridae: Lyctocorinae) from the Eocene Baltic amber
No full textFIGURE 9. Xyloesteles kerneggeriorum sp. nov.. Holotype, Nr. 290/2002 – 1, male; coll. Senkenberg Museum in Frankfurt/ Main, dorsal view.Published as part of Popov, Yuri A., Herczek, Aleksander & Ek, Jola Bro Ż, 2011, The first fossil Dufoureillini (Hemiptera: Heteroptera: Anthocoridae: Lyctocorinae) from the Eocene Baltic amber, pp. 53-60 in Zootaxa 2760 on page 58, DOI: 10.5281/zenodo.27680
Mosquito Larvicidal Constituents from Lantana Viburnoides SP Viburnoides Var Kisi (A. rich) Verdc (Verbenaceae).
No full text\ud
\ud
Lantana viburnoides sp viburnoides var kisi is used in Tanzania ethnobotanically to repel mosquitoes as well as in traditional medicine for stomach ache relief. Bioassay-guided fractionation and subtraction bioassays of the dichloromethane extract of the root barks were carried out in order to identify the bioactive components for controlling Anopheles gambiae s.s. mosquito larvae. Twenty late III or early IV instar larvae of An. gambiae s.s. were exposed to various concentrations of the plant extracts, fractions, blends and pure compounds, and were assayed in the laboratory by using the protocol of WHO 1996. Mean mortalities were compared using Dunnett's test (p < 0.05) and lethal concentration calculated by Lackfit Inversel of the SAS programme. The crude extract (LC50 = 7.70 ppm in 72 h) and fractions exhibited different level of mosquito larvicidal activity with subtraction of some fractions resulting in activity enhancement. The active fractions contained furanonaphthaquinones regio-isomers (LC50 = 5.48-5.70 ppm in 72 h) and the lantadene triterpenoid camaric acid (LC50 = 6.19 ppm in 72 h) as active principles while the lupane triterpenoid betulinic acid (LC50 < 10 ppm in 72 h) was obtained from the least active fraction. Crude extracts and some fractions had higher or comparable larvicidal activity to the pure compounds. These results demonstrate that L. viburnoides sp viburnoides var kisi extracts may serve as larvicides for managing various mosquito habitats even in their semi-purified form. The isolated compounds can be used as distinct markers in the active extracts or plant materials belonging to the genus Lantana
Influence of Uracil in Fermentation Media on β-Glucan Production by Agrobacterium Radiobacter A 1.5 and Agrobacterium sp. Bro 1.2.1
No full textOptimum β-glucan production can be achieved by an optimum condition in the fermentation media. Uracil, as a precursor of UDP-glucose, may act as a glucose donor in the formation of polysaccharides such as β-glucan. It is expected that addition of certain quantity of uracil into the fermentation media in a suitable growth phase of Agrobacterium radiobacter A 1.5 and Agrobacterium sp. Bro 1.2.1, will significantly increase the β-glucan production. In this investigation, 0.025%; 0.05% or 0.1% of uracil were added into the fermentation media during the logarithmic phase (24 hour) or stationary phase (46 hour) of growth. The β-glucan product was evaluated from the β-glucan (crude) dry-weight and from the β-glucan content. Beta-glucan content was determined as glucose by the Hisamatsu-AOAC and HPLC methods. The highest β-glucan (crude) dry-weight produced by the A. 1.5 was in a medium containg 0.025% uracil (24 hour), whilst by the A. Bro 1.2.1 was in a medium containg 0.1% uracil (46 hour), both higher than control. The highest β-glucan content produced by the A. 1.5 (27.03%) was in a medium containg 0.025% uracil (46 hour), while control produced only 23.28%. The highest β-glucan content produced by the Bro 1.2.1 (29.34%) was in a medium containg 0.025% uracil (24 hour), while control produced only 28.75%. Two-way anova analysis showed that there were no significant influence difference (α = 0,05) from various concentration of uracil in either growth phases, to the yield of β-glucan (crude) dry-weight nor to the β-glucan equivalent glucose content
- …
