The spectral signature of recent climate change

Spectrally resolved measurements of the Earth’s reflected shortwave (RSW) and outgoing longwave radiation (OLR) at the top of the atmosphere intrinsically contain the imprints of a multitude of climate relevant parameters. Here, we review the progress made in directly using such observations to diagnose and attribute change within the Earth system over the past four decades. We show how changes associated with perturbations such as increasing greenhouse gases are expected to be manifested across the spectrum and illustrate the enhanced discriminatory power that spectral resolution provides over broadband radiation measurements. Advances in formal detection and attribution techniques and in the design of climate model evaluation exercises employing spectrally resolved data are highlighted. We illustrate how spectral observations have been used to provide insight into key climate feedback processes and quantify multi-year variability but also indicate potential barriers to further progress. Suggestions for future research priorities in this area are provided

A study of the time evolution of GERB shortwave calibration by comparison with CERES Edition-3A data

This study examines the evolution of the GERB-2 and GERB-1 Edition 1 shortwave radiance calibration between 2004-2007 and 2007-2012 respectively, through comparison with CERES instrument FM1 Edition 3A SSF instantaneous radiances. Two periods when simultaneous observations from both GERB-2 and GERB-1 were available, January 13th to February 11th 2007 and May 1st to May 10th 2007, are also compared. For these two overlap periods respectively, averaged over all CERES ‘unfiltered-to-filtered radiance ratio’ subsets, the GERB-1/CERES unfiltered radiance ratio is on average found to be 1.6% and 1.9% lower than the associated GERB-2/CERES unfiltered radiance ratio. Over the two longer time series the GERB/CERES unfiltered radiance ratio shows a general decrease with time for both GERB-2 and GERB-1. The rate of decrease varies through time but no significant seasonal dependence is seen. Averaged over all subsets the GERB-2/CERES unfiltered radiance ratio showed a decrease of 1.9% between June 2004 and June 2006. Between June 2007 and June 2012, the corresponding decrease in the GERB-1/CERES unfiltered radiance ratio was 6.5%. The evolution of the GERB/CERES unfiltered radiance ratio for both GERB-2 and GERB-1 shows a strong dependence on the CERES unfiltered-to-filtered radiance ratio, indicating that it is spectrally dependent. Further time-series analysis and theoretical work using simulated spectral radiance curves suggests that for GERB-1 the evolution is consistent with a darkening in the GERB shortwave spectral response function which is most pronounced at the shortest wavelengths. For GERB-2, no single spectral cause can be identified, suggesting that the evolution is likely due to a combination of several different effects

A 7-year follow-up of sacral anterior root stimulation for bladder control in patients with a spinal cord injury: quality of life and users' experiences\ud

Study design: Cross-sectional descriptive study.\ud \ud Objectives: To assess long-term effects and quality of life (QoL) of using sacral anterior root stimulation (SARS) in spinal cord injured patients.\ud \ud Setting: Neurosurgical and Urological Departments of a large teaching hospital and a large rehabilitation centre in the Netherlands.\ud \ud Methods: In all, 42 patients with complete spinal cord injury (SCI) implanted between 1987 and 2000 were included. A questionnaire was constructed to determine complications, technical failures and personal experiences of the patients. The Qualiveen questionnaire was used and the outcome was compared with data obtained from a reference group of 400 SCI patients with neurogenic bladder problems not using the bladder controller. The Qualiveen questionnaire measures disease-specific aspects in four domains with respect to limitations, constraints, fears and feelings and general QoL aspects, suitable for use in SCI patients with urinary disorders.\ud \ud Results: The results of 37 patients are presented. Our results with the bladder controller with respect to medical and technical complications and infection rates are similar to the results presented by others. From users' experiences, the most important advantages reported were a decreased infection rate (68%), improved social life (54%) and continence (54%). Comparison of the obtained results of our patient group with the Qualiveen questionnaire with a reference group not using the bladder controller indicates that the specific impact of urinary disorders in the four domains on QoL is reduced and that general QoL is improved.\ud \ud Conclusion: SARS is effective and safe for neurogenic bladder management in patients with complete SCI. Users' experiences are positive. Furthermore, this therapy seems to reduce the effects of urinary-disorder-specific QoL aspects, and to increase the QoL in general\u

Solid-state NMR characterisation of the thermal transformation of a Hungarian white illite

1H, 27Al, 29Si and 39K solid-state NMR are reported from a Hungarian illite 2:1 clay for samples heated up 1600 °C. This single-phase sample has a small amount of aluminium substitution in the silica layer and very low iron-content (0.4 wt%). Thermal analysis shows several events that can be related to features in the NMR spectra, and hence changes in the atomic scale structure. As dehydroxylation occurs there is increasing AlO4 and AlO5-contents. The silica and gibbsite layers become increasingly separated as the dehydroxylation progresses. Between 900 and 1000 °C the silica layer forms a potassium aluminosilicate glass. The gibbsite-layer forms spinel/γ-Al2O3 and some aluminium-rich mullite. Then on heating to 1600 °C changes in the 29Si and 27Al MAS NMR spectra are consistent with the aluminosilicate glass increasing its aluminium-content, the amount of mullite increasing probably with its silicon-content also increasing, and some α-Al2O3 forming

The influence of dust optical properties on the colour of simulated MSG-SEVIRI Desert Dust infrared imagery

Satellite imagery of atmospheric mineral dust is sensitive to the optical properties of the dust, governed by the mineral refractive indices, particle size, and particle shape. In infrared channels the imagery is also sensitive to the dust layer height and to the surface and atmospheric environment. Simulations of mineral dust in infrared "Desert Dust" imagery from the Spinning Enhanced Visible and InfraRed Imager (SEVIRI) have been performed, using the COSMO-MUSCAT (COSMO: COnsortium for Small-scale MOdelling; MUSCAT: MUltiScale Chemistry Aerosol Transport Model) dust transport model and the Radiative Transfer for TOVS (RTTOV) program, in order to investigate the sensitivity of the imagery to assumed dust properties. This paper introduces the technique and performs initial validation and comparisons with SEVIRI measurements over North Africa for daytime hours during 6 months covering June and July of 2011–2013. Using T-matrix scattering theory and assuming the dust particles to be spherical or spheroidal, wavelength- and size-dependent dust extinction values are calculated for a number of different dust refractive index databases, along with several values of the particle aspect ratio, denoting the particle shape. The consequences for the infrared extinction values of both the particle shape and the particle orientation are explored: this analysis shows that as the particle asphericity increases, the extinctions increase if the particles are aligned horizontally, and decrease if they are aligned vertically. Randomly oriented spheroidal particles have very similar infrared extinction properties as spherical particles, whereas the horizontally and vertically aligned particles can be considered to be the upper and lower bounds on the extinction values. Inputting these values into COSMO-MUSCAT-RTTOV, it is found that spherical particles do not appear to be sufficient to describe fully the resultant colour of the dust in the infrared imagery. Comparisons of SEVIRI and simulation colours indicate that of the dust types tested, the dust refractive index dataset produced by Volz (1973) shows the most similarity in the colour response to dust in the SEVIRI imagery, although the simulations have a smaller range of colour than do the observations. It is also found that the thermal imagery is most sensitive to intermediately sized particles (radii between 0.9 and 2.6µm): larger particles are present in too small a concentration in the simulations, as well as with insufficient contrast in extinction between wavelength channels, to have much ability to perturb the resultant colour in the SEVIRI dust imagery

Effect of praziquantel treatment of Schistosoma mansoni during pregnancy on intensity of infection and antibody responses to schistosome antigens: results of a randomised, placebo-controlled trial

BACKGROUND: Praziquantel treatment of schistosomiasis during pregnancy was only recommended in 2002; hence the effects of treatment during pregnancy are not fully known. We have therefore evaluated the effects on infection intensity and the immunological effects of praziquantel treatment against Schistosoma mansoni during pregnancy, compared with treatment after delivery. METHODS: A nested cohort of 387 Schistosoma mansoni infected women was recruited within a larger trial of de-worming during pregnancy. Women were randomised to receive praziquantel or placebo during pregnancy. All women were treated after delivery. Infection intensity after treatment was assessed by a single Kato-Katz examination of stool samples with duplicate slides and categorised as undetected, light (1-99 eggs per gram (epg)), moderate (100-399 epg) or heavy (>or=400 epg). Antibodies against S. mansoni worm and egg antigens were measured by ELISA. Results were compared between women first treated during pregnancy and women first treated after delivery. RESULTS: At enrollment, 252 (65.1%) of the women had light infection (median (IQR) epg: 35 (11, 59)), 75 (19.3%) moderate (median (IQR) epg: 179(131, 227)) and 60 (15.5%) had heavy infection (median (IQR) epg: 749 (521, 1169)) with S. mansoni. At six weeks after praziquantel treatment during pregnancy S. mansoni infection was not detectable in 81.9% of the women and prevalence and intensity had decreased to 11.8% light, 4.7% moderate and 1.6% heavy a similar reduction when compared with those first treated after delivery (undetected (88.5%), light (10.6%), moderate (0.9%) and heavy (0%), p = 0.16). Parasite specific antibody levels were lower during pregnancy than after delivery. Praziquantel treatment during pregnancy boosted anti-worm IgG isotypes and to a lesser extent IgE, but these boosts were less pronounced than in women whose treatment was delayed until after delivery. Praziquantel had limited effects on antibodies against egg antigens. CONCLUSION: S mansoni antigen-specific antibody levels and praziquantel-induced boosts in antibody levels were broadly suppressed during pregnancy, but this was not associated with major reduction in the efficacy of praziquantel. Long-term implications of these findings in relation to resistance to re-infection remain to be explored

Antibody Responses to <i>Schistosoma mansoni</i> Schistosomula Antigens

While antigens from Schistosoma schistosomula have been suggested as potential vaccine candidates, the association between antibody responses with schistosomula antigens and infection intensity at reinfection is not well known. Schistosoma mansoni-infected individuals were recruited from a schistosomiasis endemic area in Uganda (n = 372), treated with 40 mg/kg praziquantel (PZQ) and followed up at five weeks and at one year post-treatment. Pre-treatment and five weeks post-treatment immunoglobulin (Ig) E, IgG1 and IgG4 levels against recombinant schistosomula antigens rSmKK7, rSmLy6A, rSmLy6B and rSmTSP7 were measured using ELISA. Factors associated with detectable pre-treatment or post-treatment antibody response against the schistosomula antigens and the association between five-week antibody responses and one year post-treatment reinfection intensity among antibody responders were examined. Being male was associated with higher pre-treatment IgG1 to rSmKK7, rSmLy6a and AWA. Five weeks post-treatment antibody responses against schistosomula antigens were not associated with one year post-treatment reinfection intensity among antibody responders' antibody levels against rSmKK7, rSmLy6B and rSmTSP7 dropped, but increased against rSmLy6A, AWA and SEA at five weeks post-treatment among antibody responders. S. mansoni-infected individuals exhibit detectable antibody responses to schistosomula antigens that are affected by treatment. These findings indicate that schistosomula antigens induce highly varied antibody responses and could have implications for vaccine development

Retrievals of high latitude surface emissivity across the infrared from high altitude aircraft flights

We present retrievals of infrared spectral surface emissivities spanning the far and mid infrared from aircraft observations over Greenland, taken at an altitude of 9.2 km above sea level. We describe the flight campaign, available measurements and the retrieval method. The principal barriers to reducing uncertainty in the emissivity retrievals are found to be instrumental noise and our ability to simultaneously retrieve the underlying surface temperature. However, our results indicate that using the instrumentation available to us it is possible to retrieve emissivities from altitude with an uncertainty of ~ 0.02 or better across much of the infrared. They confirm that the far‐infrared emissivity of snow and ice surfaces can depart substantially from unity, reaching values as low as 0.9 between 400‐450 cm‐1. They also show good consistency with retrievals from the same flight made from near‐surface observations giving confidence in the methodology used and the results obtained for this more challenging viewing configuration. To the best of our knowledge, this is the first time that far‐infrared surface emissivity has been retrieved from altitude and demonstrates that the methodology has the potential to be extended to planned satellite far‐infrared missions

Advances in understanding mineral dust and boundary layer processes over the Sahara from Fennec aircraft observations

The Fennec climate program aims to improve understanding of the Saharan climate system through a synergy of observations and modelling. We present a description of the Fennec airborne observations during 2011 and 2012 over the remote Sahara (Mauritania and Mali) and the advances in the understanding of mineral dust and boundary layer processes they have provided. Aircraft instrumentation aboard the UK FAAM BAe146 and French SAFIRE Falcon 20 is described, with specific focus on instrumentation specially developed and relevant to Saharan meteorology and dust. Flight locations, aims and associated meteorology are described. Examples and applications of aircraft measurements from the Fennec flights are presented, highlighting new scientific results delivered using a synergy of different instruments and aircraft. These include: (1) the first airborne measurement of dust particles sized up to 300 microns and associated dust fluxes in the Saharan atmospheric boundary layer (SABL), (2) dust uplift from the breakdown of the nocturnal low-level jet before becoming visible in SEVIRI satellite imagery, (3) vertical profiles of the unique vertical structure of turbulent fluxes in the SABL, (4) in-situ observations of processes in SABL clouds showing dust acting as CCN and IN at −15 °C, (5) dual-aircraft observations of the SABL dynamics, thermodynamics and composition in the Saharan heat low region (SHL), (6) airborne observations of a dust storm associated with a cold-pool (haboob) issued from deep convection over the Atlas, (7) the first airborne chemical composition measurements of dust in the SHL region with differing composition, sources (determined using Lagrangian backward trajectory calculations) and absorption properties between 2011 and 2012, (8) coincident ozone and dust surface area measurements suggest coarser particles provide a route for ozone depletion, (9) discrepancies between airborne coarse mode size distributions and AERONET sunphotometer retrievals under light dust loadings. These results provide insights into boundary layer and dust processes in the SHL region – a region of substantial global climatic importance