Trend in seasonal amplitude of northern net ecosystem production: Simulated results from IAP DGVM in CAS-ESM2

Atmospheric and Oceanic Science Letters, Journal Year: 2023, Volume and Issue: 17(2), P. 100445 - 100445

Published: Nov. 16, 2023

Net ecosystem production (NEP) over northern latitudes has an obvious seasonal variation, which dominantly drives the variation in atmospheric CO2. Investigating these carbon processes and understanding underlying drivers is a key issue of climate research. This study focuses on amplitude NEP (40°–90°N) investigates its trend period 1990–2014 by using dynamic global vegetation model (IAP DGVM) second version Chinese Academy Sciences Earth System Model (CAS-ESM2). Basing spin-up simulation, we conduct control simulation to evaluate modeled NEP, three sensitivity simulations detect contributions The results show that increases significantly from 1990 2014, with 9.69 TgC month−1 yr−1, mainly because increasing maximum NEP. positive largely reduced when separately exclude CO2 fertilization effects climatic effects. These significant reductions suggest important change Even though uncertainties remain, favor further development IAP DGVM accurately simulating terrestrial cycle, also provide reference for application CAS-ESM investigating carbon–climate interactions. 北方陆地净生态系统生产力(NEP)具有明显的季节变化特征, 这是大气CO2季节变化的关键驱动.研究这些碳循环过程并理解潜在的驱动因素是气候研究的一个关键问题.本文利用第二代中国科学院地球系统模式(CAS-ESM2)中的全球植被动态模型(IAP DGVM), 研究了1990−2014年北方NEP(40°−90°N)的季节振幅及其变化趋势.在初始化试验的基础上, 本文开展了一个控制试验来评估模拟的北方NEP季节幅度的变化趋势, 同时开展了三个敏感性试验来研究气候和大气CO2的贡献.结果表明:1990−2014年, 模拟的北方NEP季节振幅显著增加, 趋势为9.69 这主要是由于最大NEP增加所致.当分别排除CO2施肥效应和气候效应时, 上述增加趋势大大减弱.这些显著的减少表明大气CO2和气候变化对北方NEP的季节性振幅有重要影响.尽管模式存在不确定性, 但这些结果有利于进一步提升IAP DGVM对陆地碳循环的精确模拟, 也为CAS-ESM研究碳-气候相互作用的应用提供了重要参考.

Language: Английский

The Impact of Meteorological Drought at Different Time Scales from 1986 to 2020 on Vegetation Changes in the Shendong Mining Area

Remote Sensing, Journal Year: 2024, Volume and Issue: 16(15), P. 2843 - 2843

Published: Aug. 2, 2024

The Shendong Mining Area, being the largest coal base in world, has significant challenges intensive development and utilization of resources, as well impact a dry climate, which can have serious negative effects on growth flora region. Investigating spatial temporal patterns how meteorological drought affects vegetation Area at various time scales offer scientific foundation for promoting sustainable ecological restoration This study utilizes Standardized Precipitation Evapotranspiration Index (SPEI) Normalized Difference Vegetation (NDVI) data from 1986 to 2020 Area. It employs Slope trend analysis, Mann–Kendall test, Geographic Detector, other methods examine spatiotemporal distribution characteristics scales. Additionally, investigates influence these Across mining area, there was general decrease monthly average SPEI an annual basis. However, seasonal, semi-annual, basis, gradual increase SPEI, with higher rate southern region compared northern When considering variation different seasons, both positive trends were observed winter summer. mainly western part while eastern part. In spring, area generally experienced drought, autumn, it more precipitation. exhibits prevailing vegetation, greater extent southeast lesser northwest. coverage near mine is insufficient, resulting low NDVI value, makes prone drought. Over past few years, coverage, indicating successful efforts. Various forms land use exhibit distinct responses forests displaying most correlation barren strongest correlation. types landforms varying Loess ridge hill demonstrate pronounced association monthly-scale values, whereas alluvial floodplain display poorest yearly scale values. findings this research be summarized follows: (1) pattern increased humidity, pace humidity having intensified recent times. Seasonal variations consistent cyclic patterns. (2) There are regional disparities notable peak decline majority recovery. (3) Regional element that influences changes Nevertheless, displays complexity obviously impacted by factors small scale. (4) should noted exert despite their relatively coverage. predominant type locations grasslands; however, they minor SPEI. (5) A shorter period, elevation, steeper slope gradient all contribute larger

Language: Английский

NAO Signal in the Increased Interannual Variability of Spring Vegetation in Northeast Asia After the Early 2000s

Journal of Geophysical Research Atmospheres, Journal Year: 2024, Volume and Issue: 129(23)

Published: Nov. 29, 2024

Abstract Based on the leaf area index (LAI) and normalized difference vegetation (NDVI) from 1982 to 2020, this study reveals a significant increase in intensity of interannual variability (IIV) spring (April–May) over Northeast Asia since early 2000s. This change is closely linked notable IIV April surface air temperatures former period (1986–2001) latter (2002–2016). Further analysis also highlights salient impact North Atlantic Oscillation (NAO) strengthened vegetation. During period, there substantial March NAO compared with period. greater allows positive significantly influence net heat fluxes, thereby leading phase tripole (NAT) sea temperature (SST) pattern March. Given persistence SSTs, NAT SST lasts April, subsequently causing height anomalies through wave train that originates propagates downstream. process consequently results an hence local Thus, increased conducive enhancing Asia.

Language: Английский