Atmospheric composition and thermodynamic retrievals from the ARIES airborne TIR-FTS system--Part 2: Validation and results from aircraft campaigns

This study validates trace gas and thermodynamic retrievals from nadir infrared spectroscopic measurements recorded by the UK Met Office Airborne Research Interferometer Evaluation System (ARIES) – a thermal infrared, Fourier transform spectrometer (TIR-FTS) on the UK Facility for Airborne Atmospheric Measurements (FAAM) BAe-146 aircraft.Trace-gas-concentration and thermodynamic profiles have been retrieved and validated for this study throughout the troposphere and planetary boundary layer (PBL) over a range of environmental variability using data from aircraft campaigns over and around London, the US Gulf Coast, and the Arctic Circle during the Clear air for London (ClearfLo), Joint Airborne IASI (Infrared Atmospheric Sounding Interferometer) Validation Experiment (JAIVEx), and Measurements, process studies, and Modelling (MAMM) aircraft campaigns, respectively. Vertically resolved retrievals of temperature and water vapour (H2O), and partial-column retrievals of methane (CH4), carbon monoxide (CO), and ozone (O3) (over both land and sea) were compared to corresponding measurements from high-precision in situ analysers and dropsondes operated on the FAAM aircraft. Average degrees of freedom for signal (DOFS) over a 0–9 km column range were found to be 4.97, 3.11, 0.91, 1.10, and 1.62 for temperature, H2O, CH4, CO, and O3, respectively, when retrieved on 10 vertical levels. Partial-column mean biases (and bias standard error) between the surface and ~ 9 km, when averaged across all flight campaigns, were found to be −0.7(±0.3) K, −479(±56) ppm, −11(±2) ppb, −3.3(±1.0) ppb, and +3.5(±1.0) ppb, respectively, whilst the typical a posteriori (total) uncertainties for individually retrieved profiles were 0.4, 9.5, 5.0, 21.2, and 15.0 %, respectively.Averaging kernels (AKs) derived for progressively lower altitudes show improving sensitivity to lower atmospheric layers when flying at lower altitudes. Temperature and H2O display significant vertically resolved sensitivity throughout the column, whilst trace gases are usefully retrieved only as partial-column quantities, with maximal sensitivity for trace gases other than H2O within a layer 1 and 2 km below the aircraft. This study demonstrates the valuable atmospheric composition information content that can be obtained by ARIES nadir TIR remote sensing for atmospheric process studies

Morfofisiologia de plantas de milho em competição com picão-preto e trapoeraba submetidas a roçada Morphophysiology of corn plants in competition with picão-preto and trapoeraba submitted to clearings

Avaliou-se a eficiência do uso de roçadas no controle de picão-preto (Bidens pilosa) e trapoeraba (Commelina benghalensis) por meio de características morfológicas e fisiológicas do milho. O experimento foi realizado em condições controladas no ano agrícola 2009/2010. As características fisiológicas foram obtidas em parcela subdividida, sendo realizadas quatro avaliações no decorrer do ciclo do milho: 1ª - antes da primeira roçada (V3); 2ª - após a primeira roçada (V6); 3ª - após a segunda roçada (V9); e 4ª - plantas de milho no estádio de florescimento, por meio de um analisador de gases no infravermelho. Duas roçadas reduziram a interferência das plantas daninhas B. pilosa e C. benghalensisnas características morfológicas do milho. A roçada não influenciou os aspectos fisiológicos nas plantas de milho em competição com as plantas daninhas. C. benghalensis causou maior interferência nas características fisiológicas do milho, reduzindo a fotossíntese e a transpiração. A espécie B. pilosa, quando não roçada, apresentou maior capacidade de interferência na morfologia do milho.<br>The efficiency of using clearings to control Picão-preto (Bidens pilosa) and Trapoeraba (Commelina benghalensis) was evaluated based on the morphological and physiological characteristics of corn. An experiment under greenhouse conditions was conducted in 2009/2010. The physiological characteristics were obtained in a subdivided parcel, with four evaluations being performed throughout the corn cycle (1- before the first clearing (V3); 2- after the first clearing (V6);3- after the second clearing (V9); and 4- corn plants at the fluorescence stage), by means of Infra Red Gas Analyzer. Two clearings reduced the influence of B. pilosa and C. benghalensis weeds on the morphological characteristics of corn. The clearing did not influence the physiological aspects of the corn plants in competition with weeds. C. benghalensis caused a greater interference in the physiological characteristics of corn, reducing photosynthesis and transpiration. When not cleared, B. pilosa species had a greater capacity of interfering in corn morphology