Estimativa dos componentes do balanço radiativo à superfície mediante satélites meteorológicos / Estimation of components the budget radiation surface by using meteorological satellites

AUTOR(ES)
DATA DE PUBLICAÇÃO

2004

RESUMO

The budget between incoming radiation surface and outgoing is called Budget Radiation Surface (BRS). Conventional methods of measure of this budget are prompt and therefore representative of small areas, while that the meteorological satellites allow to all have a regular covering of the globe. This thesis has as objective basic to analyze methods of estimate of the components of the BRS being used itself only of satellite information, using or developing parameterization that, in the measure of the possible one, prevent complex models and fill space and secular gaps of information on the system Land-atmosphere. For the parameterization of each one of the components of the BRS they had been used given generated for satellites NOAA-16 and GOES-8. For estimate the solar radiation to the surface model GL1.2 was used, that o uses information of the canal of the GOES-8 and operationally in the CPTEC-INPE. The daily average error in monthly scale is +10 Wm-2 (with annual oscillation of ±10 Wm-2) and deviation standard 25 Wm-2. This is the order of the error in the balance of radiation of shortwave. However, the GL1.2 overestimates the radiation in regions that present considerable aerosol load proceeding from forest fires. The component of radiation of ascending longwave (OLA) was esteem from information of temperature and emissividade of the surface; the first one was using algorithms split-window, e second from the Normalized Differences Vegetation Index (NDVI). The main sources of error in the estimate of the OLA must to the uncertainty in the estimate of the temperature of the surface and to the contamination for clouds. The error during the daylight is generally less that 20 Wm-2, and less 10 Wm-2 for the nocturnal period. For estimate of the radiation of descending longwave (OLD) a parameterization was developed that depends on the average temperature in low the troposphere and on the precipitável water, both by satellite. The specter of the OLD for the regions between the 4 and 7,5 mm (R1) and 13 the 50 mm (R3) if adjusts to the one of a black body, whose temperature corresponds to the average temperature of the responsible layers for at least 90% of the OLD. The region of atmospheric window the OLD depends on the amount of precipitável water. The clouds can clearly introduce a difference with sky conditions up to 100 Wm-2 in the region of atmospheric window; this difference will be bigger the measure that the base of the cloud if finds next to the surface. The errors of estimate of this component are of the same order of precision of the pyrgeometer, or either ±10%. Components OLA and OLD can be of the same even though bigger order of magnitude or of the one than the solar radiation; however, the balance of radiation of long wave is of inferior order. In consequence, the BRS approximately presents a linear relation with the incident solar radiation. Although the balance of radiation of long wave is of second order with relation to the one of short wave, it has influence in the coefficients of the linear relation during the daylight and is essential during the nocturnal period. Therefore, the accuracy estimates of OLA and OLD continue being important.

ASSUNTO(S)

meteorology satélites meteorológicos radiação de onda longa metereological sattelites parameterization solar radiation balanço de radiação à superfície radiação solar surface radiation budget parametrização meteorologia long wave radiation

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