An Estimation Method of "Day" Scale Primary Productivity Based on Instantaneous Photosynthetic Rate Integration

Abstract

The invention relates to a day-scale primary productivity estimation method based on instantaneous photosynthetic rate integration, and the method comprises the following steps of (1) calculation of instantaneous photosynthetic rate: establishing a cubic equation through a relationship formula among the coupled instantaneous photosynthetic rate, intercellular carbon dioxide (CO2) concentration and stomatal conductance, and calculating the instantaneous photosynthetic rate; (2) simulation of instantaneous weather data: simulating the instantaneous weather by utilizing a sinusoidal function through the characteristic that the temperature and radiation diurnal variation follows the sinusoidal variation principle; and (3) calculation of day-scale primary productivity integration: substituting the instantaneous photosynthetic rate solved in the step (1) in the simulated weather data to form a function adopting the time as a variable, utilizing a trapezoid or simpson formula to integrate the time, and acquiring the day-scale primary productivity. By utilizing the diurnal variation principle characteristics of the weather data and combining the instantaneous photosynthetic rate calculation formula, the measurement precision is high.

Description

Technical field [0001] The invention relates to a large field of global carbon cycle parameter measurement and a small field of primary productivity time scale conversion, and in particular to a "day" scale primary productivity estimation method based on numerical integration of instantaneous photosynthesis rate. Background technique [0002] Primary productivity is a key factor in the carbon balance of terrestrial ecosystems, and it is also the original source of ecosystem carbon flux. Ecosystem carbon flux is characterized by different time scales, including "instantaneous", "hour", "day", "month" and "year". Although most of the mechanism models are based on the instantaneous scale, since most of the meteorological data are "day" scale data, the "day" scale primary productivity estimation data based on meteorological data is the most widely used in ordinary research. Therefore, it is necessary to establish a conversion of primary productivity from the “instantaneous” scale to...

AI Technical Summary

Problems solved by technology

In the current research on the conversion from "instantaneous" to "day" scale, either the diurnal variation characteristics of meteorological elements are not considered, or the mechanism model of the relationship between photosynthetic rate and stomatal conductance is not introduced for calculation, and the calculation of primary productivity at the "day" scale is easy. Produce overestimates or underestimates, which limits in-depth and accurate research on the global carbon cycle

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