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The inverse relationship between nitrate and temperature(N-T relationship) has been used to estimate new production from remotely sensed sea surface temperature at the regional or global scale of oceans. This study aimed to develop a time-series model of the N-T relationship from automated, continuous hourly observations over two years on the coast of Halifax, Canada. The model demonstrated time-series variability of the N-T relationship at a coastal station on the Nova Scotia Shelf, with adjusted R 2 =0.999 4 and RMSE=0.025 7. The maximum residual value was 0.077. The annual temperature variations described a sine curve, and daily, weekly, and monthly variations fluctuated within the normal ranges, controlled by the local climate. The annual variation of nitrate concentration formed nearly a sine curve. Heavy or longlasting rainfall increased nitrate concentration by 4 to 30-fold in 24 h, and then the increased nitrogen was quickly depleted by phytoplankton growth in 10 to 48 h. In general, biological activity was a key factor in causing nitrate concentration change, dependent mainly on seawater temperature. The power function of the N-T relationship observed in our study area could be used to quickly estimate sea surface nitrate concentration, in combination with temperature data obtained by remote sensing.
The inverse relationship between nitrate and temperature (NT relationship) has been used to estimate new production from remotely sensed sea surface temperature at the regional or global scale of oceans. This study aims to develop a time-series model of the NT relationship from automated, Continuous hourly observations over two years on the coast of Halifax, Canada. The model demonstrated time-series variability of the NT relationship at a coastal station on the Nova Scotia Shelf, with adjusted R2 = 0.999 4 and RMSE = 0.025 7. The maximum The annual temperature variation describes a sine curve, and daily, weekly, and monthly variations fluctuated within the normal ranges, controlled by the local climate. The annual variation of nitrate concentration formed nearly a sine curve. Heavy or longlasting rainfall increased nitrate concentration by 4 to 30-fold in 24 h, and then the the increased nitrogen was quickly depleted by phytoplankton growth in 10 to 48 h. In ge neral, biological activity was a key factor in causing nitrate concentration change, dependent mainly on seawater temperature. The power function of the NT relationship observed in our study area could be used to quickly estimate sea surface nitrate concentration, in combination with temperature data obtained by remote sensing.