Method and device for estimating clear sky solar radiation in oasis farmland

Abstract

The invention relates to a method and a device for estimating clear sky solar radiation in an oasis farmland. The method comprises the following steps: determining the earth's surface albedo and the earth's surface reflectance; utilizing a thermal infrared wave band to determine the earth's surface temperature, and affirming that the earth's surface temperature is equal to the air temperature based on the standard reference surface within the range of the oasis farmland; utilizing ground measured data to acquire downstream short-wave radiation and downstream long-wave radiation; utilizing the acquired data to determine the ratio of net radiation flux, average daily net radiation and instantaneous net radiation, the ratio of daytime net radiation to the instantaneous net radiation, and the ratio of the instantaneous net radiation at time t2 and the instantaneous net radiation at satellite passing time t1; according to the ratio of the net radiation flux, the average daily net radiation and the instantaneous net radiation, the ratio of the daytime net radiation to the instantaneous net radiation, and the ratio of the instantaneous net radiation at time t2 and the instantaneous net radiation at satellite passing time t1, determining the average daily net radiation, the daytime net radiation and the net radiance at any time point.

Description

technical field [0001] The invention relates to the technical field of solar radiation, in particular to a method and device for estimating clear-sky solar radiation in oasis farmland. Background technique [0002] Not all the short-wave radiation emitted from the sun reaches the surface, and a considerable part of it is reflected, scattered or absorbed by clouds, different molecules and aerosol particles in the atmosphere during the transmission through the atmosphere. Components such as water vapor and low clouds in the atmosphere and the earth's surface start to emit long-wave radiation upward after absorbing solar radiation. [0003] Surface net radiation (Rn) is the sum of the input and output of long-wave radiation and short-wave radiation on the surface, representing the balance of surface energy absorption, reflection and scattering. As a heat source, it provides the heating or cooling of the surface and the atmosphere close to the ground, as well as the heat consum...

AI Technical Summary

Problems solved by technology

However, the retrieved diurnal net radiation and daily mean net radiation are all overestimated, and all the results have obvious errors

[0016] In short, when the net radiation cannot be measured, the existing models are limited by the location, date and satellite transit time of the oasis farmland area, and it is difficult to meet various existing needs

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