ABSTRACT

In this study, the relationship between vegetation dynamics and atmospheric patterns over Iceland from 2001-2019 has been assessed using remote sensing. This study is based on MODIS NDVI images, NCEP/NCAR reanalysis dataset and values of the North Atlantic Oscillation (NAO). The results show that the vegetation coverage in Iceland reaches a maximum in the period from the middle of July to late August, with an average of about 65% of the total area (66858 km²). There is not a strong relationship between NAO phases and the occurrence of the dry (less vegetation) or green months, which means that a dry year can be accompanied by a negative NAO phase (i.e. July 2009 with NDVI anomaly=-3.35 and NAO =-2.15) or with a positive phase (September 2005 with NDVI anomaly=-2.23 and NAO=0.63). The most important factor influencing the occurrence of months with denser/less dense vegetation is shifting west/eastward of Greenland Low height (GL), which is accompanied by a green/dry month in Iceland, respectively. The knowledge of this can help us to understand the variations in Iceland's vegetation and also enables us to have a closer look at the impact of changes in global atmospheric patterns on the vegetation productivity in Iceland.

摘要

在这项研究中，使用遥感评估了 2001-2019 年冰岛植被动态与大气模式之间的关系。本研究基于 MODIS NDVI 图像、NCEP/NCAR 再分析数据集和北大西洋涛动 (NAO) 值。结果表明，冰岛植被覆盖度在7月中旬至8月下旬达到最大值，平均约为总面积（66858 km ^2）的65%左右。）。NAO 阶段与干旱（植被较少）或绿色月份的发生之间没有很强的关系，这意味着干旱年可以伴随负 NAO 阶段（即 2009 年 7 月，NDVI 异常=-3.35 和 NAO = -2.15) 或正相位（2005 年 9 月，NDVI 异常=-2.23 且 NAO=0.63）。影响植被密度较高/较低的月份出现的最重要因素是格陵兰低海拔 (GL) 向西/向东移动，这分别伴随着冰岛的绿色/干旱月份。了解这一点可以帮助我们了解冰岛植被的变化，也可以让我们更深入地了解全球大气格局的变化对冰岛植被生产力的影响。