Cavity ring-down spectroscopy of (H2O)-O-18 in the range 16 570-17 120 cm(-1)

Cavity ring-down spectroscopy is used to record an absorption spectrum of (H2O)-O-18 water vapor in the 16570-17 120 cm(-1) region. In the spectrum, 596 lines are identified as belonging to (H2O)-O-18, of which 375 lines are assigned by comparing to newly calculated theoretical lines. The spectrum covers the entire 5v polyad and two new vibrational band origins, (321) at 16775.381 cm(-1) and (401) at 16854.991 cm(-1) are determined. (C) 2004 Elsevier Inc. All rights reserved

Fast Simulators for Satellite Cloud Optical Centroid Pressure Retrievals, 1. Evaluation of OMI Cloud Retrievals

The cloud Optical Centroid Pressure (OCP), also known as the effective cloud pressure, is a satellite-derived parameter that is commonly used in trace-gas retrievals to account for the effects of clouds on near-infrared through ultraviolet radiance measurements. Fast simulators are desirable to further expand the use of cloud OCP retrievals into the operational and climate communities for applications such as data assimilation and evaluation of cloud vertical structure in general circulation models. In this paper, we develop and validate fast simulators that provide estimates of the cloud OCP given a vertical profile of optical extinction. We use a pressure-weighting scheme where the weights depend upon optical parameters of clouds and/or aerosol. A cloud weighting function is easily extracted using this formulation. We then use fast simulators to compare two different satellite cloud OCP retrievals from the Ozone Monitoring Instrument (OMI) with estimates based on collocated cloud extinction profiles from a combination of CloudS at radar and MODIS visible radiance data. These comparisons are made over a wide range of conditions to provide a comprehensive validation of the OMI cloud OCP retrievals. We find generally good agreement between OMI cloud OCPs and those predicted by CloudSat. However, the OMI cloud OCPs from the two independent algorithms agree better with each other than either does with the estimates from CloudSat/MODIS. Differences between OMI cloud OCPs and those based on CloudSat/MODIS may result from undetected snow/ice at the surface, cloud 3-D effects, low altitude clouds missed by CloudSat, and the fact that CloudSat only observes a relatively small fraction of an OMI field-of-view

Three Way Comparison between Two OMI/Aura and One POLDER/PARASOL Cloud Pressure Products

The cloud pressures determined by three different algorithms, operating on reflectances measured by two space-borne instruments in the "A" train, are compared with each other. The retrieval algorithms are based on absorption in the oxygen A-band near 760 nm, absorption by a collision induced absorption in oxygen near 477nm, and the filling in of Fraunhofer lines by rotational Raman scattering. The first algorithm operates on data collected by the POLDER instrument on board PARASOL, while the latter two operate on data from the OMI instrument on board Aura. The satellites sample the same air mass within about 15 minutes. Using one month of data, the cloud pressures from the three algorithms are found to show a similar behavior, with correlation coefficients larger than 0.85 between the data sets for thick clouds. The average differences in the cloud pressure are also small, between 2 and 45 hPa, for the whole data set. For optically thin to medium thick clouds, the cloud pressure the distribution found by POLDER is very similar to that found by OMI using the O2 - O2 absorption. Somewhat larger differences are found for very thick clouds, and we hypothesise that the strong absorption in the oxygen A-band causes the POLDER instrument to retrieve lower pressures for those scenes

Deep-ultraviolet cavity ringdown spectroscopy

The sensitive optical detection technique of cavity ringdown spectroscopy is extended to the wavelength range 197-204 nm. A novel design narrowband Fourier-transform-limited laser is used, and the technique is applied to gas-phase extinction measurements in CO2, SF6, and O-2. Further demonstration of the system capabilities is given in high-resolution recordings of the Schumann-Runge (0, 0), (1, 0), and (2, 0) bands in O-2. (C) 2004 Optical Society of America

Cavity ring-down spectroscopy of (H2O)-O-17 in the range 16570-17125 cm(-1)

Following previous investigations on (H2O)-O-16 and (H2O)-O-18 by cavity ring-down spectroscopy, this method has now been applied to investigate the energy region of the 5 nu polyad in the absorption spectrum of (H2O)-O-17. In the range 16570-17125 cm(-1). the highest energy range investigated for the (H2O)-O-17 isotopologue so far, 516 lines are attributed to (H2O)-O-17 and assigned from a newly generated line list. (C) 2006 Elsevier Inc. All rights reserved

Reviewing ecopsychology research: exploring five databases and considering the future

This brief article aims to provide an overview of the current dispersal of the term ecopsychology within the academic literature. It summarizes the results found when entering the term ecopsychology into five academic databases. The numbers of hits are discussed and comparisons are made with other related terms. The results are further broken down to provide a snapshot of the type of material referred to in these searches. A more detailed inspection of the material referenced in journal articles is undertaken. Here, popular outlets and dates of publication are highlighted. A final search for articles that report original research data directly associated with ecopsychology is also reported. Possible reasons for the low yield and the implications of this are highlighted along with suggested pathways forward

Vagal nerve stimulation started just prior to reperfusion limits infarct size and no-reflow

Vagal nerve stimulation (VNS) started prior to, or during, ischemia has been shown to reduce infarct size. Here, we investigated the effect of VNS when started just prior to, and continued during early, reperfusion on infarct size and no-reflow and studied the underlying mechanisms. For this purpose, swine (13 VNS, 10 sham) underwent 45 min mid-LAD occlusion followed by 120 min of reperfusion. VNS was started 5 min prior to reperfusion and continued until 15 min of reperfusion. Area at risk, area of no-reflow (% of infarct area) and infarct size (% of area at risk), circulating cytokines, and regional myocardial leukocyte influx were assessed after 120 min of reperfusion. VNS significantly reduced infarct size from 67 ± 2 % in sham to 54 ± 5 % and area of no-reflow from 54 ± 6 % in sham to 32 ± 6 %. These effects were accompanied by reductions in neutrophil (~40 %) and macrophage (~60 %) infiltration in the infarct area (all p < 0.05), whereas systemic circulating plasma levels of TNFα and IL6 were not affected. The degree of cardioprotection could not be explained by the VNS-induced bradycardia or the VNS-induced decrease in the double product of heart rate and left ventricular systolic pressure. In the presence of NO-synthase inhibitor LNNA, VNS no longer attenuated infarct size and area of no-reflow, which was paralleled by similarly unaffected regional leukocyte infiltration. In conclusion, VNS is a promising novel adjunctive therapy that limits reperfusion injury in a large animal model of acute myocardial infarction

Transmission spectrum of Venus as a transiting exoplanet

On 5-6 June 2012, Venus will be transiting the Sun for the last time before 2117. This event is an unique opportunity to assess the feasibility of the atmospheric characterisation of Earth-size exoplanets near the habitable zone with the transmission spectroscopy technique and provide an invaluable proxy for the atmosphere of such a planet. In this letter, we provide a theoretical transmission spectrum of the atmosphere of Venus that could be tested with spectroscopic observations during the 2012 transit. This is done using radiative transfer across Venus' atmosphere, with inputs from in-situ missions such as Venus Express and theoretical models. The transmission spectrum covers a range of 0.1-5 {\mu}m and probes the limb between 70 and 150 km in altitude. It is dominated in UV by carbon dioxide absorption producing a broad transit signal of ~20 ppm as seen from Earth, and from 0.2 to 2.7 {\mu}m by Mie extinction (~5 ppm at 0.8 {\mu}m) caused by droplets of sulfuric acid composing an upper haze layer above the main deck of clouds. These features are not expected for a terrestrial exoplanet and could help discriminating an Earth-like habitable world from a cytherean planet.Comment: 4 pages, 3 figures, 1 table. Figure 3 and Table 1 will be only available on-line. Table 1 will be fully available at the CDS. Accepted for publication in Astronomy and Astrophysics (Letter