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Full-Text Articles in Physical Sciences and Mathematics

Uncertainty In Simulating Gross Primary Production Of Cropland Ecosystem From Satellite-Based Models, Wenping Yuan, Wenwen Cai, Anthony L. Nguy-Robertson, Huajun Fang, Andrew E. Suyker, Yang Chen, Wenjie Dong, Shuguang Liu, Haicheng Zhang Apr 2015

Uncertainty In Simulating Gross Primary Production Of Cropland Ecosystem From Satellite-Based Models, Wenping Yuan, Wenwen Cai, Anthony L. Nguy-Robertson, Huajun Fang, Andrew E. Suyker, Yang Chen, Wenjie Dong, Shuguang Liu, Haicheng Zhang

School of Natural Resources: Faculty Publications

Accurate estimates of gross primary production (GPP) for croplands are needed to assess carbon cycle and crop yield. Satellite-based models have been developed to monitor spatial and temporal GPP patterns. However, there are still large uncertainties in estimating cropland GPP. This study compares three light use efficiency (LUE) models (MODIS-GPP, EC-LUE, and VPM) with eddy-covariance measurements at three adjacent AmeriFlux crop sites located near Mead, Nebraska, USA. These sites have different croprotation systems (continuous maize vs. maize and soybean rotated annually) and water management practices (irrigation vs. rainfed). The results reveal several major uncertainties in estimating GPP which need to …


Estimation Of Daily Air Temperature Based On Modis Land Surface Temperature Products Over The Corn Belt In The Us, Linglin Zeng, Brian D. Wardlow, Tsegaye Tadesse, Jie Shan, Michael Hayes, Deren Li, Daxiang Xiang Jan 2015

Estimation Of Daily Air Temperature Based On Modis Land Surface Temperature Products Over The Corn Belt In The Us, Linglin Zeng, Brian D. Wardlow, Tsegaye Tadesse, Jie Shan, Michael Hayes, Deren Li, Daxiang Xiang

Center for Advanced Land Management Information Technologies: Publications

Air temperature (Ta) is a key input in a wide range of agroclimatic applications. Moderate Resolution Imaging Spectroradiometer (MODIS) Ts (Land Surface Temperature (LST)) products are widely used to estimate daily Ta. However, only daytime LST (Ts-day) or nighttime LST (Ts-night) data have been used to estimate Tmax/Tmin (daily maximum or minimum air temperature), respectively. The relationship between Tmax and Ts-night, and the one between Tmin and Ts-day has not been studied. In this study, both the ability of Ts-night data to estimate Tmax and the ability of Ts-day data to estimate Tmin were tested and studied in the Corn …


Studying Air Pollutants Origin And Associated Meteorological Parameters Over Seoul From 2000 To 2009, Sunmin Park, Hesham El-Askary, Ismail Sabbah, Hanbin Kwak, Anup K. Prasad, Woo-Kyun Lee, Menas Kafatos Jan 2015

Studying Air Pollutants Origin And Associated Meteorological Parameters Over Seoul From 2000 To 2009, Sunmin Park, Hesham El-Askary, Ismail Sabbah, Hanbin Kwak, Anup K. Prasad, Woo-Kyun Lee, Menas Kafatos

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

We investigate the temporal characteristics of major air pollutants collected from 44 air quality stations over the city of Seoul, Korea, namely, nitrogen dioxide, carbon monoxide, particular matter at 10 microns, and sulfur dioxide (SO2) between 2000 and 2009. The corresponding satellite datasets, namely, aerosol optical depth (AODsat), Ångström exponent, and fine mode fraction, collected from moderate resolution imaging spectroradiometer (MODIS) as well as the Aeronet ground aerosol optical depth (AODaeronet), have been analyzed. Pollutants’ seasonal effect has been inferred from the precipitation and temperature. The four pollutants under study show varying temporal characteristics with different …