This paper evaluates the performance of various linear ozone photochemistry parametrizations using the stratosphere-troposphere data assimilation system of the Met Office. A set of experiments were ...run for the period 23 September 2003 to 5 November 2003 using the Cariolle (v1.0 and v2.1), LINOZ and Chem2D-OPP (v0.1 and v2.1) parametrizations. All operational meteorological observations were assimilated, together with ozone retrievals from the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS). Experiments were validated against independent data from the Halogen Occultation Experiment (HALOE) and ozonesondes. Additionally, a simple offline method for comparing the parametrizations is introduced. It is shown that in the upper stratosphere and mesosphere, outside the polar night, ozone analyses are controlled by the photochemistry parametrizations and not by the assimilated observations. The most important factor in getting good results at these levels is to pay attention to the ozone and temperature climatologies in the parametrizations. There should be no discrepancies between the climatologies and the assimilated observations or the model, but there is also a competing demand that the climatologies be objectively accurate in themselves. Conversely, in the lower stratosphere outside regions of heterogeneous ozone depletion, the ozone analyses are dominated by observational increments and the photochemistry parametrizations have little influence. We investigate a number of known problems in LINOZ and Cariolle v1.0 in more detail than previously, and we find discrepancies in Cariolle v2.1 and Chem2D-OPP v2.1, which are demonstrated to have been removed in the latest available versions (v2.8 and v2.6 respectively). In general, however, all the parametrizations work well through much of the stratosphere, helped by the presence of good quality assimilated MIPAS observations.
A study examined global maps of nitrous oxide and water mixing obtained by the Upper Atmosphere Research Satellite. Mixing of air from the troposphere to the stratosphere may be responsible for ...transporting air across the tropics.
The COST 723 Action Lahoz, W. A.; Buehler, S. A.; Legras, B.
Quarterly journal of the Royal Meteorological Society,
October 2007, Letnik:
133, Številka:
S2
Journal Article
The laboratory tests for the use of sapogenic amphiphilic glycosides as a coagulation–flocculation aid are presented in this paper. These amphiphilic glycosides were obtained, through a natural ...fermentation process, of the juice, of fique (
Furcraea
sp.) leaves. Decantation allows for the separation of a supernatant denominated “supernatant fique juice” and a decanted fraction denominated “decanted fique juice.” The latter contains most of the sapogenic amphiphilic glycosides and was mixed with the chemical coagulant ferric chloride hexahydrate, at varying doses. Ferric chloride hexahydrate was also used as a control to ascertain the removal efficiency of persistent contaminants from samples of a textile industry effluent. The parameters of interest were typical indicators of water quality such as color, turbidity, chemical oxygen demand, pH and conductivity. The results indicate that the decanted fique juice, when used as a coagulation–flocculation aid, and upon comparison with the chemical coagulant alone, causes an additional color and turbidity reduction of 31 and 17 %, respectively. No significant differences were noted in the chemical oxygen demand values (
α
= 0.05;
P
< 0.001). Thus, there is a scope for further research about the commercial feasibility of DFJ as an industrial water treatment agent, which reduces the toxicity of raw fique juice and its detrimental environmental effects.
This paper describes the capabilities of a nadir thermal infrared (TIR) sensor proposed for deployment onboard a geostationary platform to monitor ozone (O3 ) and carbon monoxide (CO) for air quality ...(AQ) purposes. To assess the capabilities of this sensor we perform idealized retrieval studies considering typical atmospheric profiles of O3 and CO over Europe with different instrument configuration (signal to noise ratio, SNR, and spectral sampling interval, SSI) using the KOPRA forward model and the KOPRA-fit retrieval scheme. We then select a configuration, referred to as GEO-TIR, optimized for providing information in the lowermost troposphere (LmT; 0-3 km in height). For the GEO-TIR configuration we obtain ~1.5 degrees of freedom for O3 and ~2 for CO at altitudes between 0 and 15 km. The error budget of GEO-TIR, calculated using the principal contributions to the error (namely, temperature, measurement error, smoothing error) shows that information in the LmT can be achieved by GEO-TIR. We also retrieve analogous profiles from another geostationary infrared instrument with SNR and SSI similar to the Meteosat Third Generation Infrared Sounder (MTG-IRS) which is dedicated to numerical weather prediction, referred to as GEO-TIR2. We quantify the added value of GEO-TIR over GEO-TIR2 for a realistic atmosphere, simulated using the chemistry transport model MOCAGE (MOdèle de Chimie Atmospherique à Grande Echelle). Results show that GEO-TIR is able to capture well the spatial and temporal variability in the LmT for both O3 and CO. These results also provide evidence of the significant added value in the LmT of GEO-TIR compared to GEO-TIR2 by showing GEO-TIR is closer to MOCAGE than GEO-TIR2 for various statistical parameters (correlation, bias, standard deviation).
This paper presents a community effort to develop good practice guidelines for the validation of global coarse-scale satellite soil moisture products. We provide theoretical background, a review of ...state-of-the-art methodologies for estimating errors in soil moisture data sets, practical recommendations on data pre-processing and presentation of statistical results, and a recommended validation protocol that is supplemented with an example validation exercise focused on microwave-based surface soil moisture products. We conclude by identifying research gaps that should be addressed in the near future.
•Satellite soil moisture validation methods are reviewed•Community-agreed validation good practice guidelines are presented•A standardized satellite soil moisture validation protocol is provided
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