Intraseasonal variabilities exist in terms of Eurasian vegetation growth in summer, as estimated by the Normalized Difference Vegetation Index (NDVI). The spatiotemporal patterns of Eurasian NDVI in June are significantly different from those in July and August (JA), especially over eastern Europe and western Siberia (50°–70°N, 30°–90°E; abbreviated as EEWS). Meanwhile, June and JA EEWS‐NDVI respond differently to the Atlantic sea surface temperature in May over coastal regions (35°–60°N, 20°W–20°E; abbreviated as ACSST). During 1982–2015, the JA EEWS‐NDVI is significantly related to May ACSST (correlation coefficient: 0.44, significant at the 1% level), whereas the June EEWS‐NDVI shows only a slight and nonsignificant relationship (correlation coefficient: 0.23). In June, the EEWS‐NDVI is primarily influenced by the local 2‐m temperature (correlation coefficient: 0.62, significant at the 1% level), whereas in JA it is more closely linked with soil moisture (correlation coefficient: 0.38, significant at the 5% level). Increased May ACSST corresponds to lower surface air temperature and increased precipitation, which is accompanied by higher soil moisture over the EEWS region, and a persistently high soil moisture from May to JA is favorable for the growth of vegetation. However, the surface air temperature in June responding to higher ACSST is slightly lower, which is not conducive to the vegetation growth in June. Numerical experiments are carried out using CAM5, and the results support the proposed physical mechanisms. Therefore, May ACSST is a possible climatic factor responsible for the intraseasonal variabilities of EEWS‐NDVI, which may serve as a predictor of JA vegetation over Eurasia.

中文翻译：

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夏季大西洋海面温度对夏季欧亚NDVI季节内变化的影响

根据归一化植被指数（NDVI）估算，夏季欧亚植被生长存在季节内变化。欧亚NDVI在6月与7月和8月（JA）的时空格局有显着差异，尤其是在东欧和西伯利亚西部（50°–70°N，30°–90°E；缩写为EEWS）。同时，6月和JA EEWS‐NDVI对5月沿海地区（35°–60°N，20°W–20°E；缩写为ACSST）的大西洋海表温度的响应有所不同。在1982-2015年期间，JA EEWS-NDVI与5月的ACSST显着相关（相关系数：0.44，在1％的水平上具有显着性），而6月的EEWS-NDVI则显示出很小的且不显着的关系（相关系数：0.23）。在六月，EEWS‐NDVI主要受当地2−m温度的影响（相关系数：0.62，在1％的水平上显着），而在JA中，它与土壤水分联系更紧密（相关系数：0.38，在5％的显着水平）水平）。5月ACSST升高对应于较低的地表气温和降水增加，并伴有EEWS地区较高的土壤湿度，从5月至JA持续高的土壤湿度有利于植被的生长。但是，由于ACSST升高，6月份的地表气温略低，不利于6月份的植被生长。使用CAM5进行了数值实验，结果支持了所提出的物理机制。因此，