Mesospheric vertical thermal structure and winds on Venus from HHSMT CO spectral-line observations

We report vertical thermal structure and wind velocities in the Venusian mesosphere retrieved from carbon monoxide (¹²CO J=2-1 and ¹³CO J=2-1) spectral line observations obtained with the Heinrich Hertz Submillimeter Telescope (HHSMT). We observed the mesosphere of Venus from two days after the second Messenger flyby of Venus (on 5 June 2007 at 23:10 UTC) during five days. Day-to-day and day-to-night temperature variations and short-term fluctuations of the mesospheric zonal flow were evident in our data. The extensive layer of warm air detected recently by SPICAV at 90-100 km altitude is also detected in the temperature profiles reported here.These data were part of a coordinated ground-based Venus observational campaign in support of the ESA Venus Express mission. Furthermore, this study attempts to cross-calibrate space- and ground-based observations, to constrain radiative transfer and retrieval algorithms for planetary atmospheres, and to contribute to a more thorough understanding of the global patterns of circulation of the Venusian atmosphere.     

Lanthanoid behaviour in an acidic landscape

Lanthanoids were studied in a boreal landscape where an abundance of acid sulfate soils and Histosols provide a unique opportunity to increase the understanding of how these metals behave in acidic soils and waters and interact with soil and aqueous organic matter. In the acid sulfate soils lanthanoids are mobile as reflected in high to very high concentrations in soil water and runoff (typically a few mg l⁻¹ but up to 12 mg l⁻¹) and abundant release by several relatively weak extractants (ammonium acetate EDTA, sodium pyrophosphate, hydroxylamine hydrochloride) applied on bulk soil. Normalisation with the lanthanoid pool in the underlying parent materials (sulphide-bearing sediments deposited in brackish-water) and soil water showed that the extensive release/retention in the acidic soil was accompanied by large, and variable, fractionation trends across the lanthanoid series. In low-order streams draining these soils, the lanthanoid concentrations were high and, as indicated by frontal ultrafiltration and geochemical modelling, largely dissolved (<1 kDa) in the form of the species LnSO₄⁺ and Ln³⁺. In other moderately acidic stream waters (pH 4.3-4.6), organic complexation was predicted to be important in the <1 kDa fraction (especially for the heavy lanthanoids) and strongly dominating in the colloidal phase (1 kDa-0.45 μm). Along the main stem of a stream in focus (catchment area of 223 km²), lanthanoid concentrations increased downstream, in particular during high flows, caused by a downstream increase in the proportion of acid sulfate soils which are extensively flushed during wet periods. The geochemical models applied to the colloidal Ln-organic phase were not successful in predicting the measured fractionation patterns.     

Luminescence dating of canal sediments from Angkor Borei, Mekong Delta, Southern Cambodia

Work to apply luminescence dating to archaeological sites in the Lower Mekong Delta has continued with a programme aimed at dating ancient canal sediments and brick monuments in the vicinity of ancient city of Angkor Borei. Following the successful application of OSL dating to the Paris 2 canal near Angkor Borei further fieldwork and analysis has been undertaken. The infill and substrate of the larger Paris 4 canal connecting Angkor Borei to Oc Eo, some 80 km to the south in Vietnam has been sampled and subjected to luminescence analysis. Field spectroscopy and underwater bleaching experiments were also conducted in the Baray and Angkor Borei in 2004. The results show that both illumination intensities and spectral distributions are severely altered by as little as 1.5 m of turbid water, and that OSL bleaching rates for both quartz and feldspars are reduced. Since quartz resetting is heavily dependant on the UV components in daylight, which have preferentially attenuated the effects of turbid water on OSL zeroing rates are especially marked. The new data from the Paris 4 canal, which has been dated by OSL to be between the first millenium BC and the late first millenium AD are significant to understanding the archaeological development of the Fu Nan state in the Lower Mekong Delta, and the sequence of development of the canal network linking inland agrarian sites and coastal trading centres.     

Factors driving international technology transfer: empirical insights from a CDM project survey

This study empirically explores factors driving international technology transfer via Clean Development Mechanism (CDM) projects by explicitly considering factors that have been identified in the literature on international technology transfer as being relevant for transfer success. These factors include technological characteristics, such as the novelty and complexity of a technology, as well as the use of different transfer channels. Employing data from an original survey of CDM project participants, the econometric analysis also distinguishes between knowledge and equipment transfer. The findings suggest that more complex technologies and the use of export as a transfer channel are both associated with a higher degree of technology transfer. Projects involving two- to five-year-old technologies seem more likely to involve technology transfer than both younger and older technologies. Energy supply and efficiency projects are correlated with a higher degree of technology transfer than non-energy projects. Unlike previous studies, technology transfer was not related to project size, to the length of time a country has hosted CDM projects, or to the host country's absorptive capacity. The findings for knowledge and equipment transfer are similar, but not identical.

Policy relevance

CDM projects are often seen as a vehicle for the transfer of climate technologies from industrialized to developing countries. Technology transfer is an important element of the new and emerging market mechanisms and frameworks under the United Nations Framework Convention on Climate Change, such as the Technology Mechanism, Nationally Appropriate Mitigation Actions, or Intended Nationally Determined Contributions. Thus, a clearer understanding of the factors driving technology transfer may help policy makers in their design of such mechanisms. For the CDM, this may be achieved by including more stringent technology transfer requirements in countries’ CDM project approval processes. Based on our findings, such policies should focus particularly on energy supply and efficiency technologies. Likewise, it may be beneficial for host countries to condition project approval on the novelty and complexity of technologies and adjust these provisions over time. Since such technological characteristics are not captured systematically by project design documents, using a survey-based evaluation opens up new opportunities for a more holistic and targeted evaluation of technology transfer in CDM projects.     

An interdisciplinary approach to the collapse of the port and degradation of freshwater resources at Panama Viejo (Panama), 1519–1671

The Archaeological Site of Panama Viejo (Panama) comprises a protected area of 28 km² within present-day Panama City, on America's Pacific coast. In 1519, the Spaniards founded the city of Panama Viejo to secure a natural port in an area inhabited by indigenous peoples since at least the eighth century CE. The site, along the coastline and between two rivers, became a principal gateway for goods and people travelling between Europe and Pacific settlements to the east (Realejo) and the west (Trujillo, Lima, Arica). Within one century, however, Panama Viejo's natural port and freshwater infrastructure collapsed, leading to the city's relocation after corsairs attacked it in 1671. This study combines archaeological, geographical and historical analyses to explain how and why human interactions with the local environment made the settlement increasingly untenable.     

Optical properties of Titan and early Earth haze laboratory analogs in the mid-visible

Scattering and absorption of sunlight by aerosols are integral to understanding the radiative balance of any planetary atmosphere covered in a haze, such as Titan and possibly the early Earth. One key optical parameter of an aerosol is its refractive index. We have simulated both Titan and early Earth organic haze aerosols in the laboratory and measured the real and imaginary portion of their refractive index at λ = 532 nm using cavity ringdown aerosol extinction spectroscopy. This novel technique allows analysis on freely-floating particles minutes after formation. For our Titan analog particles, we find a real refractive index of n = 1.35 ± 0.01 and an imaginary refractive index k = 0.023 ± 0.007, and for the early Earth analog particles we find n = 1.81 ± 0.02 and k = 0.055 ± 0.020. The Titan analog refractive index has a smaller real and similar imaginary refractive index compared to most previous laboratory measurements of Titan analog films, including values from Khare et al. (Khare, B.N., Sagan, C., Arakawa, E.T., Suits, F., Callcott, T.A., Williams, M.W. [1984]. Icarus 60, 127-137). These newly measured Titan analog values have implications for spacecraft retrievals of aerosol properties on Titan. The early Earth analog has a significantly higher real and imaginary refractive index than Titan analogs reported in the literature. These differences suggest that, for a given amount of aerosol, the early Earth analog would act as a stronger anti-greenhouse agent than the Titan analog.