659 research outputs found
Dust layer effects on the atmospheric radiative budget and heating rate profiles,
No full textThe effect of mineral aerosol optical properties and vertical distribution on clear-sky, instantaneous and daily-average aerosol direct radiative effects (DREs) and heating rates (HRs) is analyzed in the solar (S, 0.3-4 μm) and terrestrial (T, 4-80 μm) spectral domain, respectively. The used radiative transfer model is based on lidar, sun-sky photometer, and radiosonde measurements. The study focuses on the Sahara dust outbreak of July 16, 2009 which advected dust particles from north-western Africa over south-eastern Italy. Clear-sky, instantaneous aerosol DREs and HRs undergo large changes within few hours, for the variability of the dust aerosol properties and vertical distribution. The daily-average, clear-sky aerosol S-DRE is near -5 Wm -2 and -12 Wm -2 at the top of the atmosphere (ToA) and surface (sfc), respectively. The daily-average aerosol T-DRE offsets the S-DRE by about one third at the ToA and by about one half at the surface. The daily average aerosol HR integrated over the whole aerosol column is 0.5 and -0.3 K day -1 in the S and T domain, respectively. Thus, the all-wave integrated HR is 0.2 K day -1. These results highlight the importance of accounting for the interaction of dust particles with T and S radiation. Sensitivity tests indicate that the uncertainties of the aerosol refractive index, size distribution, and vertical distribution have on average a large impact on aerosol HRs in the S and T domain, respectively. Refractive index and aerosol size distribution uncertainties also have a large impact on S- and T-DREs. The aerosol vertical distribution that has a negligible impact on aerosol S-DREs, is important for aerosol T-DREs. It is also shown that aerosol HRs and DREs in the terrestrial domain are affected by the water vapour vertical distribution. © 2012 Elsevier Ltd
SPACE HIERARCHY RESULTS FOR RANDOMIZED MODELS
No full textWe prove space hierarchy and separation results for randomized and other semantic models of computation with advice. Previous works on hierarchy and separation theorems for such models focused on time as the resource. We obtain tighter results with space as the resource. Our main theorems are the following. Let s(n) be any space-constructible function that is Ω(log n) and such that s(an) = O(s(n)) for all constants a, and let s ′ (n) be any function that is ω(s(n)). There exists a language computable by two-sided error randomized machines using s ′ (n) space and one bit of advice that is not computable by two-sided error randomized machines using s(n) space and min(s(n), n) bits of advice. There exists a language computable by zero-sided error randomized machines in space s ′ (n) with one bit of advice that is not computable by one-sided error randomized machines using s(n) space and min(s(n), n) bits of advice. The condition that s(an) = O(s(n)) is a technical condition satisfied by typical space bounds that are at most linear. We also obtain weaker results that apply to generic semantic models of computation
Correction to: “Radiative effects of polar stratospheric clouds” by S. Kinne and O.B. Toon
No full textComparison between calculations of shortwave radiation with different aerosol datasets and measured data at the MSU MO (Russia)
No full textThe radiation block of the COSMO non-hydrostatic mesoscale model of the atmosphere and soil active layer was tested against a relatively new effective CLIRAD(FC05)-SW radiation model and radiative measurements at the Moscow State University Meteorological Observatory (MSU MO, 55.7N, 37.5E) using different aerosol datasets in cloudless conditions. We used the data of shortwave radiation components from the Kippamp;Zonen net radiometer CNR4. The model simulations were performed with the application of various aerosol climatologies including the new MACv2 climatology and the aerosol and water vapor dataset from CIMEL (AERONET) sun photometer measurements. The application of the new MACv2 climatology in the CLIRAD(FC05)-SW radiation model provides the annual average relative error of the total global radiation of -3 varying from 0.5 in May to -7.7 in December. The uncertainty of radiative calculations in the COSMO model according to preliminary estimates changes from 1.4 to 8.4. against CLIRAD(FC05)-SW radiation model with the same parameters. We showed that in clear sky conditions the sensitivity of air temperature at 2 meters to shortwave net radiation changes is about 0.7-0.9°C per100 W/m2 due to the application of aerosol climatologies over Moscow. © 2017 Author(s)
Cell death and degeneration in the symbiotic dinoflagellates of the coral Stylophora pistillata during bleaching
No full textRising sea temperatures are increasing the incidences of mass coral bleaching (the dissociation
of the coral–algal symbiosis) and coral mortality. In this study, the effects of bleaching
(induced by elevated light and temperature) on the condition of symbiotic dinoflagellates (Symbiodinium
sp.) within the tissue of the hard coral Stylophora pistillata (Esper) were assessed using a suite
of techniques. Bleaching of S. pistillata was accompanied by declines in the maximum potential
quantum yield of photosynthesis (Fv/Fm, measured using pulse amplitude modulated [PAM] fluorometry),
an increase in the number of Sytox-green-stained algae (indicating compromised algal membrane
integrity and cell death), an increase in 2’,7’-dichlorodihydrofluroscein diacetate (H2DCFDA)-
stained algae (indicating increased oxidative stress), as well as ultrastructural changes (vacuolisation,
losses of chlorophyll, and an increase in accumulation bodies). Algae expelled from S. pistillata
exhibited a complete disorganisation of cellular contents; expelled cells contained only amorphous
material. In situ samples taken during a natural mass coral bleaching event on the Great Barrier Reef
in February 2002 also revealed a high number of Sytox-labelled algae cells in symbio. Dinoflagellate
degeneration during bleaching seems to be similar to the changes resulting from senescence-phase
cell death in cultured algae. These data support a role for oxidative stress in the mechanism of coral
bleaching and highlight the importance of algal degeneration during the bleaching of a reef coral
Radiative impact of Etna volcanic aerosols over south eastern Italy on 3 December 2015
No full textIrradiance and LiDAR measurements at the surface combined with satellite products from SEVIRI (Spinning Enhanced Visible and InfraRed Imager) and MODIS (MODerate resolution Imaging Spectroradiometer) were used to detect and characterize the Etna volcano (Italy) plume that crossed southeastern Italy on 3 December 2015, from about 10:00 up to 11:30 UTC, and estimate its radiative impact. The volcanic plume was delivered by a violent and short paroxysmal eruption that occurred from 02:30 to 03:10 UTC of 3 December 2015, about 400 km away from the monitoring site. Measurements from the LiDAR combined with model results showed that the aerosol optical depth of the volcanic plume, located from about 11 to 13 km above sea level (asl), was equal to 0.80 ± 0.07 at 532 nm. A low tropospheric aerosol load, located up to about 7 km asl, with optical depth equal to 0.19 ± 0.01 at 532 nm was also revealed by the LiDAR measurements. Short-Wave (SW) downward and upward irradiance measurements revealed that the instantaneous SW direct radiative forcing at the surface (DRFsurf) decreased to −146 ± 16 W m−2 at 10:50 UTC because of the volcanic plume passage. A Two-Stream radiative transfer model integrated with experimental measurements, which took into account the volcanic plume and the low tropospheric aerosol properties, was used to reproduce the SW radiative flux measurements at the surface and estimate the aerosol DRF both at the top of the atmosphere (TOA) and at the surface, in addition to the aerosol heating rate vertical profile. We found that the clear-sky, instantaneous, SW DRF at the TOA and the atmospheric forcing were equal to −112 and 33 W m-2, respectively, at 10:50 UTC that represented the time at which the volcanic plume radiative impact was the highest. The SW aerosol heating rate reached the peak value of 1.24 K day−1 at 12 km asl and decreased to −0.06 K day−1 at 11 km asl, at 10:50 UTC. The role of the aerosol load located up to about 7 km asl and the corresponding radiative impact has also been evaluated. © 2018 Elsevier Lt
Der Inklusion die Treue halten – Sieben Thesen zur Inklusion als Ereignis nach Badiou
No full textBoger JM-A. Der Inklusion die Treue halten – Sieben Thesen zur Inklusion als Ereignis nach Badiou. In: Hinz A, Kinne T, Kruschel R, Winter S, eds. Von der Zukunft her denken – Inklusive Pädagogik im Diskurs. Bad Heilbrunn: Klinkhardt; 2016
Annual cycle of aerosol direct radiative effect over southeast Italy and sensitivity studies
No full textAerosol direct radiative effect (DRE) calculations are presented to illustrate the annual cycle of the aerosol impact on the radiative energy balance of the Earth- atmosphere system over southeast Italy. Meteorological parameters from radiosondes, aerosol vertical profiles by lidar, aerosol optical and microphysical properties by ground- based Sun/ sky photometry and satellite ( MODIS) derived data of solar surface albedo, all referring to the 2003 - 2004 years, constitute the necessary input to radiative transfer simulations. The monthly evolution of both the solar and infrared aerosol direct radiative effect is examined at the top of the atmosphere (ToA), within the atmosphere and at the Earth's surface. Aside from cloud-free conditions (clear-sky), all-sky conditions are also addressed by adopting ISCCP monthly products. Model results reveal a strong seasonality of the solar aerosol DRE for southeast Italy, which is mainly driven by the available sunlight, but it is also modulated by variations in aerosol properties. Under cloud-free conditions, winter aerosol DREs are within -(6 +/- 2) W/m(2) at the ToA and -(7 +/- 2) W/m(2) at the surface, while summer aerosol DREs are within -(9 +/- 1) W/m(2) at the ToA and -(15 +/- 3) W/m(2) at the surface. The larger difference in summer indicates that the heating of the aerosol layer (atmospheric forcing) is much stronger in summer and actually largest in early fall. Under all-sky conditions the solar aerosol direct radiative effect decreases to -(4 +/- 1) W/m(2) and -(3 +/- 1) W/m(2) in winter and to -(12 +/- 3) W/m(2) and -(7 +/- 1) W/m(2) in summer, at surface and ToA, respectively. Model results also reveal that solar aerosol DREs dominates infrared aerosol DREs. The performed sensitivity studies demonstrate the relatively weak impact of meteorological parameters and aerosol vertical profiles and the strong impact of solar surface albedo values. Finally, it is shown that the simulated all-sky aerosol DRE at the surface is consistent with radiometer measurements
Cutaneous and pulmonal habronemosis transmitted by Musca domestica in a stable in the United Arab Emirates
No full textMultibeam bathymetry processed data (Kongsberg EM 122 transit dataset) of RV MARIA S. MERIAN during cruise MSM79/2, Atlantic Ocean
No full textThe multibeam echo sounder (MBES) data was collected from the 07.12.2018 (16:34 UTC) to the 13.12.2018 (10:34 UTC) with the Kongsberg EM122 on RV Maria S. Merian during the transit from Mindelo (Capo Verde) to Bahia de las Minas (Panama) in the Atlantic Ocean (MSM79/2). The deep-water MBES EM122 operates with an acoustic frequency of 12 kHz and a beam opening angle of 2° x 2°. The raw and unprocessed bathymetric and backscatter data is stored in Kongsberg format (*.all), each containing up to 60 min of data. The therein included time, motion and position data (WGS84, geographic) was measured by the Kongsberg Seapath system on board. During the acquisition the echo sounder was monitored as well as settings and filter adjusted according to the environment. The swath opening angle was set to 65° and the travieling speed was about 10 - 13 kn. As the data was collected during transit, no specific survey was performed. A sound velocity profile acquired during a previous cruise was applied in the MBES acquisition software SIS. The SVP data is not part of this submission.
The data was post-processed using the software QPS Qimera. No further SVP re-computation, navigation correction or tide correction was applied. Erroneous depth measurements were deleted manually by using the swath and slice editor. The vertical datum is mean sea level (MSL). The cleaned data was exported in gsf format as well as bathymetric grids in a resolution of 100 m (geotiff format, geographic coordinates in WGS84 UTM zone 22N (EPSG: 32622) to 26N (EPSG: 32626). The coordinate system is indicated in the file name
- …
