A time series of Advanced Very High Resolution Radiometer (AVHRR) derived normalized difference vegetation index (NDVI) data were compared to National Agricultural Statistics Service (NASS) corn yield data in the United States Corn Belt from 1982 to 2014. The main objectives of the comparison were to assess 1) the consistency of regional Corn Belt responses to El Niño/Southern Oscillation (ENSO) teleconnection signals, and 2) the reliability of using NDVI as an indicator of crop yield.

Regional NDVI values were used to model a seasonal curve and to define the growing season — May to October. Seasonal conditions in each county were represented by NDVI and land surface temperature (LST) composites, and corn yield was represented by average annual bushels produced per acre. Correlation analysis between the NDVI, LST, corn yield, and equatorial Pacific sea surface temperature anomalies revealed patterns in land surface dynamics and corn yield, as well as typical impacts of ENSO episodes.

It was observed from the study that growing seasons coincident with La Niña events were consistently warmer, but El Niño events did not consistently impact NDVI, temperature, or corn yield data. Moreover, the El Niño and La Niña composite images suggest that impacts vary spatially across the Corn Belt. While corn is the dominant crop in the region, some inconsistencies between corn yield and NDVI may be attributed to soy crops and other background interference. The overall correlation between the total growing season NDVI anomaly and detrended corn yield was 0.61(p = 0.00013), though the strength of the relationship varies across the Corn Belt.

比较了1982年至2014年美国玉米带国家农业统计局（NASS）玉米单产的先进超高分辨率辐射计（AVHRR）归一化差异植被指数（NDVI）数据的时间序列。比较是为了评估1）区域玉米带对厄尔尼诺/南方涛动（ENSO）远程连接信号的一致性，以及2）使用NDVI作为作物产量指标的可靠性。

区域NDVI值用于模拟季节性曲线并定义生长季节-5月至10月。每个县的季节性条件用NDVI和地表温度（LST）复合材料表示，玉米产量用每英亩平均年蒲式耳产量表示。NDVI，LST，玉米产量和赤道太平洋海面温度异常之间的相关分析揭示了陆地表面动态和玉米产量的模式，以及ENSO事件的典型影响。

从研究中观察到，与拉尼娜事件相吻合的生长季节一直较暖，但厄尔尼诺事件并未始终影响NDVI，温度或玉米单产数据。此外，厄尔尼诺和拉尼娜的合成图像表明，整个玉米带的影响在空间上都不同。尽管玉米是该地区的主要农作物，但玉米单产和NDVI之间的一些不一致可能归因于大豆作物和其他背景干扰。尽管整个玉米带之间的关系强度不同，但总生长期NDVI异常与去趋势玉米产量之间的总体相关性为0.61（p = 0.00013）。