Search results for "Plane"
showing 10 items of 6821 documents
On the atmospheric dependence of the split-window equation for land surface temperature
1994
Abstract A split-window equation is derived for land surface temperature, yielding T = T4 + A(T4 − T5) + B(e), where T is the true surface temperature, T4 and T5 are the brightness temperatures measured in AVHRR channels 4 and 5, A is a coefficient related to the atmospheric transmittances in AVHRR channels 4 and 5, being dependent on the atmosphere type and independent on surface emissivity, and B(e) takes into account the emissivity effect, which depends on both the channel surface emissivities (e4 and e5) and the atmosphere type. The atmospheric dependence of split-window coefficients, A and B(e), is discussed by means of satellite measurements simulations and in situ data. It is shown t…
Ultra-sensitive chiral sensing and analysis from the nanoscale to the earth’s atmosphere
2020
Chirality plays an essential role in life and, therefore, in modem science. I’ll present novel technologies for ultra-sensitive, absolute, chiral sensing and analysis, in all phases, from the nanoscale to the earth’s atmosphere.
Night-time cloud cover estimation
2004
In this paper a method for cloud cover assessment at night-time (when only thermal infrared data are available) is presented. It is based on the analysis of long wave radiation transfer processes in partially cloudy areas, which led to the formulation of a simplified model of the surface–cloud–atmosphere system. The model was implemented in an operational and iterative algorithm to solve the radiative equations. The algorithm was validated using ground data collected at four meteorological stations in Argentina during November 1997 and May–June 1998, which were compared to cloudiness derived from National Oceanic and Atmospheric Administration Advanced Very High Resolution Radiometer therma…
Atmospheric water vapour content retrieval from visible and thermal data in the framework of the DAISEX campaigns
2005
In this paper three methods are presented that retrieve the atmospheric water vapour from DAIS (digital airborne imaging spectrometer) data in the framework of the DAISEX (DAIS Experiment) campaigns carried out by ESA (European Space Agency). The three methodologies analysed in the paper are: (i) the ratio technique, in which the water vapour is obtained from visible and near‐infrared bands; (ii) the split‐window technique; and (iii) the split‐window covariance‐variance ratio technique, in which the water vapour content is retrieved from thermal infrared bands. A comparison between the atmospheric water vapour content extracted from the DAIS images using these techniques and that obtained f…
Biogeochemical Cycling of Nitrogen on the Early Earth
2013
Variations in the nitrogen isotope composition of ancient organic matter and associated sediments provide clues for the early evolution of Earth's atmosphere–ocean–biosphere system. In particular, large isotopic variations have been linked to the protracted oxygenation of Earth's atmosphere during the Precambrian. Important problems being investigated include the nature of the variations observed at specific times in Earth's history and the degree of preservation of ancient nitrogen biogeochemical signatures during diagenesis and metamorphism. Interpreting these records in Archean sedimentary environments and their possible implications for the evolution of Earth's early atmosphere, ocean, …
South East tropical Atlantic warm events and southern African rainfall
2003
[1] Intrusions of warm equatorial water in the South East Atlantic Ocean off Angola and Namibia may be linked with above average rainfall along the coast of those countries but sometimes also with inland areas of southern Africa e.g. Zambia. During the 1984, 1986, 1995 and 2001 warm events, above average rainfall occurred near the sea surface temperature (SST) anomalies and extended inland from the coast to an extent that appeared to depend on the intensity of the regional moisture convergence and atmospheric circulation anomalies. Rainfall over western Angola/Namibia is greatest for those events for which the local circulation anomalies act to strengthen the climatological westwards flux o…
Narrow-band to broad-band conversion for Meteosat-visiible channel and broad-band albedo using both AVHRR-1 and -2 channels
1995
Abstract Satellite-derived broad-band albedo offers a useful tool for monitoring surface conditions. Given the limited wavelength window of most satellite radiometers, satellite albedo studies need to define narrow-band to a broad-band transformations. Signals from the AVHRR channels on board the NOAA-11 satellite, the Meteosat visible channel and a rectangular spectral band from 0-3 to 2.5 μm were simulated for a set of 20 representative land surfaces. The radiative transfer code described in Tanre et al. (1990) was used to obtain top of the atmosphere radiances. The derived signals were then correlated to predict broadband albedo and the Meteosal response via the two AVHRR signals. The re…
Bias correction of dynamically downscaled precipitation to compute soil water deficit for explaining year-to-year variation of tree growth over north…
2017
This paper documents the accuracy of a post-correction method applied to precipitation regionalized by the Weather Research and Forecasting (WRF) Regional Climate Model (RCM) for improving simulated rainfall and feeding impact studies. The WRF simulation covers Burgundy (northeastern France) at a 8-km resolution and over a 20-year long period (1989–2008). Previous results show a strong deficiency of the WRF model for simulating precipitation, especially when convective processes are involved. In order to reduce such biases, a Quantile Mapping (QM) method is applied to WRF-simulated precipitation using the mesoscale atmospheric analyses system SAFRAN («Système d'Analyse Fournissant des Rense…
Discriminating irrigated and rainfed olive orchards with thermal ASTER imagery and DART 3D simulation
2009
Article in Press
Microphysical and radiative characterization of a subvisible midlevel Arctic ice cluod by airborne observations - a case study
2009
During the Arctic Study of Tropospheric Aerosol, Clouds and Radiation (ASTAR) campaign, which was conducted in March and April 2007, an optically thin ice cloud was observed south of Svalbard at around 3 km altitude. The microphysical and radiative properties of this particular subvisible midlevel cloud were investigated with complementary remote sensing and in situ instruments. Collocated airborne lidar remote sensing and spectral solar radiation measurements were performed at a flight altitude of 2300 m below the cloud base. Under almost stationary atmospheric conditions, the same subvisible midlevel cloud was probed with various in situ sensors roughly 30 min later. <br><br> …