A one-dimensional chemistry model is applied to study the stable hydrogen (D) and stable oxygen isotope (17O, 18O) composition of water vapour in stratosphere and mesosphere. In the troposphere, this isotope composition is determined by “physical” fractionation effects, that are phase changes (e.g. during cloud formation), diffusion processes (e.g. during evaporation from the ocean), and mixing...

We report the design and the performances of a Raman lidar for monitoring the tropospheric aerosol backscattering and extinction coefficients, water vapor mixing ratio and cloud liquid water. After describing the system components, along with the current limitations and options for improvement, we report examples of observations. The PTU and PTO3 balloon soundings are carried on with standard i...

The main objective of this study is to use Atmospheric Radiation Measurement (ARM) intensive observation period (IOP) data to refine a cloudiness parameterization, as proposed by Xu and Randall (1996a). The cloudiness parameterization uses the large-scale average condensate (cloud water and cloud ice) mixing ratio as the primary predictor. The large-scale relative humidity and cumulus mass flux...

[1] Aerosol-cloud relationships are derived from 14 warm continental cumuli cases sampled during the 2006 Gulf of Mexico Atmospheric Composition and Climate Study (GoMACCS) by the Center for Interdisciplinary Remotely-Piloted Aircraft Studies (CIRPAS) Twin Otter aircraft. Cloud droplet number concentration is clearly proportional to the subcloud accumulation mode aerosol number concentration. A...

[1] The coupling of statistical cloud schemes with mass-flux convection schemes is addressed. Source terms representing the impact of convection are derived within the framework of prognostic equations for the width and asymmetry of the probability distribution function of total water mixing ratio. The accuracy of these source terms is quantified by examining output from a cloud-resolving model...

[1] We present the first comprehensive general circulation model study of water ice condensation and cloud formation in the Martian atmosphere. We focus on the effects of condensation in limiting the vertical distribution and transport of water and on the importance of condensation for the generation of the observed Martian water cycle. We do not treat cloud ice radiative effects, ice sedimenta...

In a field experiment the effects of irrigation with saline drainage water (seasonal average of 4.5 dS/m) and non-saline water (0.55 dS/m) applied by two different water management strategies (cyclic or blended saline water with non-saline water in different ratios) and two different irrigation methods (drip or furrow) were studied on growth and productivity of tomato (Lycopersicon esculentum M...

Corrosion of reinforced concrete is one of the major problems in the construction industry causing premature deterioration of concrete structures well before their service life. This has placed incredible financial burden on many projects and also placed safety of users at risk. A research work was carried out to evaluate the effect of water cement ratio on corrosion of steel in reinforced conc...

reactive powder concrete (rpc) is an ultra high performance concrete which has superior mechanical and physical properties. the rpc is composed of cement and very fine powders such as crushed quartz (100–600 μm) and silica fume with very low water/binder ratio (w/b) (less than 0.20) and super plasticizer (sp). the rpc has a very high compressive and tensile strength with better durability prope...

The sulphur cycle plays fundamental roles in the chemistry1–3 and climate4,5 of Venus. Thermodynamic equilibrium chemistry at the surface of Venus favours the production of carbonyl sulphide6 and to a lesser extent sulphur dioxide. These gases are transported to the middle atmosphere by the Hadley circulation cell7,8. Above the cloud top, a sulphur oxidation cycle involves conversion of carbony...