ESSDD Earth System Science Data Discussions ESSDD Earth Syst. Sci. Data Discuss. 1866-3591 Göttingen, Germany 10.5194/essd-2021-452 Vegetation photosynthetic phenology metrics in northern terrestrial ecosystems: a dataset derived from a gross primary productivity product based on solar-induced chlorophyll fluorescence Fang Jing https://orcid.org/0000-0002-4955-1212 1 2 Li Xing 3 Xiao Jingfeng 4 Yan Xiaodong https://orcid.org/0000-0002-0774-9140 5 Li Bolun 3 Liu Feng https://orcid.org/0000-0003-3383-7598 1 2 CAS Key Laboratory of Aquatic Botany and Watershed Ecology, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan 430074, China Center of Plant Ecology, Core Botanical Gardens, Chinese Academy of Sciences, Wuhan, 430074, China Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul, South Korea Earth Systems Research Center, Institute for the Study of Earth, Oceans, and Space, University of New Hampshire, Durham, NH, USA State Key Laboratory of Earth Surface Processes and Resource Ecology, Faculty of Geographical Science, Beijing Normal University, Beijing 100875, China National Natural Science Foundation of China 32101349 31 03 2022 2022 1 39 Copyright: © 2022 Jing Fang et al. 2022 This work is licensed under the Creative Commons Attribution 4.0 International License. To view a copy of this licence, visit https://creativecommons.org/licenses/by/4.0/ This article is available from https://essd.copernicus.org/preprints/essd-2021-452/ The full text article is available as a PDF file from https://essd.copernicus.org/preprints/essd-2021-452/essd-2021-452.pdf

<p>Vegetation phenology can profoundly modulate the climate-biosphere interactions and thus plays a key role in regulating the terrestrial carbon cycle and the climate. However, most previous phenology studies are based on the traditional vegetation indices, which are inadequate to characterize the seasonal activity of photosynthesis. Here, we generated an annual vegetation photosynthetic phenology dataset with a spatial resolution of 0.05 degree from 2001 to 2020, using the latest gross primary productivity product based on solar-induced chlorophyll fluorescence (GOSIF-GPP). We combined smoothing splines with multiple change-point detection to retrieve the phenology metrics: start of the growing season (SOS), end of the growing season (EOS), and length of growing season (LOS) for terrestrial ecosystems in the Northern Hemisphere. We found that the derived phenology metrics agreed better with in situ observations from the flux tower sites than vegetation indices and MODIS-GPP. Our phenology metrics captured the spatial-temporal patterns of the single and double growing season in the Northern Hemisphere. The double season was mainly from the cropland rotation and ecosystems having two different phenological cycles. In addition, we observed a trend toward advanced SOS in about 62.98 % of the land area, with a mean rate of 0.14 &plusmn; 0.01 days year<sup>-1</sup>, a trend toward delayed EOS in about 61.87 % of the area, with a mean rate of 0.19 &plusmn; 0.16 days year<sup>-1</sup>, and a trend toward extended LOS in about 70.52 % of the area, with a mean rate of 0.33 &plusmn; 0.17 days year<sup>-1</sup>. Our phenology product can be used for validating and developing phenology models or carbon cycle models, for evaluating satellite remote sensing phenology, and for monitoring climate change impacts on terrestrial ecosystems. The data are available at <a href="https://doi.org/10.6084/m9.figshare.17195009.v2" target="_blank" rel="noopener">https://doi.org/10.6084/m9.figshare.17195009.v2</a> (Fang et al. 2021).</p>