High-Resolution Satellite Imagery for Mesoscale Meteorological Studies

Johnson, David B.; Flament, Pierre; Bernstein, Robert L.

doi:10.1175/1520-0477(1994)075<0005:hrsifm>2.0.co;2

Cited by 36 publications

(21 citation statements)

References 34 publications

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“…the observed downwelling solar radiation divided by the calculated clear-sky value) and the Meteosat data, for the visible TOARs and the 11 µm BTs. (Observed errors in the geolocation of the Meteosat data were corrected, and a parallax correction was applied to all pixels (Johnson et al, 1994), using a cloud-top height of 6 km. This height was derived from vertical scans by the high-power radars at Chilbolton.…”

Section: Observed Effects Of the Cirrus Cover On Surface Fluxesmentioning

confidence: 99%

“…A parallax correction was applied to the Meteosat data (Johnson et al, 1994). This assumed a cloud-top height of 5 km, since radiosonde data collected in the CSIP area showed that, provided the lid at around 900 hPa could be overcome, convection from the surface could rise to a height of around 550 hPa (approximately 5 km).…”

Section: Analysis Of Observed Convective Initiation In the Csip Areamentioning

confidence: 99%

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Variable cirrus shading during CSIP IOP 5. I: Effects on the initiation of convection

Marsham

Morcrette

Browning

et al. 2007

Quart J Royal Meteoro Soc

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ABSTRACT:Observations from the Convective Storm Initiation Project (CSIP) show that on 29 June 2005 (Intensive Observation Period 5) cirrus patches left over from previous thunderstorms reduced surface sensible and latent heat fluxes in the CSIP area. Large-eddy model (LEM) simulations, using moving positive surface-flux anomalies, show that we expect the observed moving gaps in the cirrus cover to significantly aid convective initiation. In these simulations, the timing of the CI is largely determined by the amount of heat added to the boundary layer, but weak convergence at the rear edge of the moving anomalies is also significant.Meteosat and rain-radar data are combined to determine the position of convective initiation for all 25 trackable showers in the CSIP area. The results are consistent with the LEM simulations, with showers initiating at the rear edge of gaps, at the leading edge of the anvil, or in clear skies, in all but one of the cases. The initiation occurs in relatively clear skies in all but two of the cases, with the exceptions probably linked to orographic effects.For numerical weather prediction, the case highlights the importance of predicting and assimilating cloud cover. The results show that in the absence of stronger forcings, weak forcings, such as from the observed cirrus shading, can determine the precise location and timing of convective initiation. In such cases, since the effects of shading by cirrus anvils from previous convective storms are relatively unpredictable, this is expected to limit the predictability of the convective initiation.

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Section: Observed Effects Of the Cirrus Cover On Surface Fluxesmentioning

confidence: 99%

Section: Analysis Of Observed Convective Initiation In the Csip Areamentioning

confidence: 99%

Variable cirrus shading during CSIP IOP 5. I: Effects on the initiation of convection

Marsham

Morcrette

Browning

et al. 2007

Quart J Royal Meteoro Soc

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“…The variation of t off is not only similar to results described already by Johnson et al (1994) for NOAA satellites. It is a characteristic feature of a sun-synchronous orbit.…”

Section: Resultsmentioning

confidence: 99%

“…It was demonstrated e.g. for NOAA-11 satellite that the time offset between ±60 degrees varies not more than ±60 minutes (Johnson et al, 1994). A further advantage consists in very similar conditions of illumination in the same geographic latitude of neighbouring passes within a relatively short time interval, perhaps within the 16 days of LANDSAT repetition rate.…”

Section: Methodsmentioning

confidence: 99%

The Influence of the Time Equation on Remote Sensing Data Interpretation

Fichtelmann

Borg

Schwarz

2015

Int. Arch. Photogramm. Remote Sens. Spatial Inf. Sci.

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ABSTRACT:The interpretation of optical Earth observation data (remote sensing data from satellites) requires knowledge of the exact geographic position of each pixel as well as the exact local acquisition time. But these parameters are not available in each case. If a satellite has a sun-synchronous orbit, equator crossing time (ECT) can be used to determine the local crossing time (LCT) and its corresponding solar zenith distance. Relation between local equator crossing time (LECT) and LCT is given by orbit geometry. The calculation is based on ECT of satellite. The method of actual ECT determination for different satellites on basis of the two-line-elements (TLE), available for their full lifetime period and with help of orbit prediction package is well known. For land surface temperature (LST) studies mean solar conditions are commonly used in the relation between ECT given in Coordinated Universal Time (UTC) and LECT given in hours, thus neglecting the difference between mean and real Sun time (MST, RST). Its difference is described by the equation of time (ET). Of particular importance is the variation of LECT during the year within about ±15 minutes. This is in each case the variation of LECT of a satellite, including satellites with stable orbit as LANDSAT (L8 around 10:05 a.m.) or ENVISAT (around 10:00 a.m.). In case of NOAA satellites the variation of LECT is overlaid by a long-term orbital drift. Ignatov et al. (2004) developed a method to describe the drift-based variation of LECT that can be viewed as a formal mathematical approximation of a periodic function with one or two Fourier terms. But, nevertheless, ET is not included in actual studies of LST.Our paper aims to demonstrate the possible influence of equation of time on simple examples of data interpretation, e.g. NDVI.

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“…Les satellites défilants employés actuellement en météorologie (Johnson et al, 1994) gravitent sur des orbites situées à environ 850 km d'altitude, passant au voisinage des pôles et synchronisées par rapport au soleil, souvent appelées orbites héliosynchrones quasi polaires. On obtient ainsi pour chaque satellite une couverture de l'ensemble du globe toutes les douze heures.…”

Section: Satellites Géostationnaires Et Défilantsunclassified

Les nouveaux programmes européens de satellites météororologiques

Gillet¹

1995

Météorologie

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L'Organisation météorologique mondiale (OMM), issue d'une convention internationale rassemblant la quasi-totalité des pays du globe, a pour rôle de coordonner les activités météorologiques. Dans le domaine opérationnel, l'OMM anime le programme de la Veille météorologique mondiale, qui permet de fournir aux services météorologiques les données dans des délais très courts ; cela est nécessaire pour les prévisions météorologiques opérationnelles. L'OMM définit ses besoins en matière d'observations spatiales opérationnelles, tout comme pour les autres observations météorologiques. Cette organisation joue également un rôle majeur dans le Programme mondial de recherche sur le climat (PMRC), conduit en coopération avec le Conseil international des Unions scientifiques et, depuis 1993, avec la Commission océanographique intergouvernementale. Le PMRC, défini dès 1980, a pour objectif de faire progresser notre compréhension des bases physiques du climat et de répondre plus spécifiquement à une double interrogation :-dans quelle mesure peut-on prévoir le climat ?-quelles influences auront les activités humaines sur le climat ?

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High-Resolution Satellite Imagery for Mesoscale Meteorological Studies

Cited by 36 publications

References 34 publications

Variable cirrus shading during CSIP IOP 5. I: Effects on the initiation of convection

Variable cirrus shading during CSIP IOP 5. I: Effects on the initiation of convection

The Influence of the Time Equation on Remote Sensing Data Interpretation

Les nouveaux programmes européens de satellites météororologiques

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