Pub Date : 2026-02-03DOI: 10.1016/j.agrformet.2026.111029
Fan Wu , Kenneth J. Davis , Li Zhang , Ray G. Anderson , Jason P. Horne , Sarah Goslee , William Munger , Chenxia Cai , Yu Yan Cui , Zhan Zhao , Min Zhong
Atmospheric boundary layer simulations in weather models, important elements of air quality simulations, are coupled with land surface parameterizations. The San Joaquin Valley (SJV) of California and the Multi-state Mid-Atlantic (MMA) feature diverse land uses, including agriculture, urban areas, and forests, which pose challenges for simulating surface fluxes. This study evaluates surface fluxes in the Weather Research and Forecasting (WRF) model using physical configurations adopted by state air quality agencies in California and Pennsylvania. We compared WRF simulations with year-long eddy-covariance flux measurements from 16 sites across the two regions. Results show that the Pleim-Xiu land surface model (PX LSM) exhibits substantial heat flux biases in the SJV but lacks systematic biases in the MMA. In the SJV, the model overestimates daytime (10:00-16:00 LST) sensible heat flux (H) by 260 W m-2 (274%) and underestimates latent heat flux (LE) by 200 W m-2 (68%) at irrigated croplands and orchards during spring and summer. In the MMA, PX LSM moderately overestimates both H and LE, with stronger partitioning into H over urban surfaces and into LE over vegetation. Daytime momentum fluxes are overestimated in both regions, while nighttime biases are inconsistent. Our findings suggest that in the SJV, heat flux biases are strongly associated with irrigation during the growing season, while in the MMA, model-data residuals are limited to modest errors in the Bowen ratio and depend on land cover. Improving WRF’s representation of irrigation and land use, potentially through satellite remote sensing, may enhance surface flux simulation accuracy.
天气模式中的大气边界层模拟是空气质量模拟的重要元素,它与陆地表面参数化相耦合。加利福尼亚州的圣华金河谷(SJV)和多州大西洋中部(MMA)具有不同的土地用途,包括农业、城市地区和森林,这对模拟地表通量构成了挑战。本研究使用加州和宾夕法尼亚州州空气质量机构采用的物理配置来评估天气研究与预报(WRF)模型中的地表通量。我们将WRF模拟与两个地区16个站点的一年涡旋协方差通量测量结果进行了比较。结果表明,Pleim-Xiu陆面模式(PX LSM)在SJV中存在较大的热通量偏差,而在MMA中缺乏系统偏差。在SJV中,春夏季灌溉农田和果园白天(10:00-16:00 LST)感热通量(H)高估260 W m-2(274%),潜热通量(LE)低估200 W m-2(68%)。在MMA中,PX LSM对H和LE均有适度高估,对城市地表上的H和植被上的LE的划分更强。这两个地区白天的动量通量都被高估了,而夜间的偏差则不一致。我们的研究结果表明,在SJV中,热通量偏差与生长季节的灌溉密切相关,而在MMA中,模型数据残差仅限于Bowen比的适度误差,并取决于土地覆盖。可能通过卫星遥感改善水资源循环系统对灌溉和土地利用的反映,可以提高地表通量模拟的准确性。
{"title":"Evaluating surface fluxes in WRF using eddy-covariance flux measurements in the Western and Eastern U.S.","authors":"Fan Wu , Kenneth J. Davis , Li Zhang , Ray G. Anderson , Jason P. Horne , Sarah Goslee , William Munger , Chenxia Cai , Yu Yan Cui , Zhan Zhao , Min Zhong","doi":"10.1016/j.agrformet.2026.111029","DOIUrl":"10.1016/j.agrformet.2026.111029","url":null,"abstract":"<div><div>Atmospheric boundary layer simulations in weather models, important elements of air quality simulations, are coupled with land surface parameterizations. The San Joaquin Valley (SJV) of California and the Multi-state Mid-Atlantic (MMA) feature diverse land uses, including agriculture, urban areas, and forests, which pose challenges for simulating surface fluxes. This study evaluates surface fluxes in the Weather Research and Forecasting (WRF) model using physical configurations adopted by state air quality agencies in California and Pennsylvania. We compared WRF simulations with year-long eddy-covariance flux measurements from 16 sites across the two regions. Results show that the Pleim-Xiu land surface model (PX LSM) exhibits substantial heat flux biases in the SJV but lacks systematic biases in the MMA. In the SJV, the model overestimates daytime (10:00-16:00 LST) sensible heat flux (H) by 260 W m<sup>-2</sup> (274%) and underestimates latent heat flux (LE) by 200 W m<sup>-2</sup> (68%) at irrigated croplands and orchards during spring and summer. In the MMA, PX LSM moderately overestimates both H and LE, with stronger partitioning into H over urban surfaces and into LE over vegetation. Daytime momentum fluxes are overestimated in both regions, while nighttime biases are inconsistent. Our findings suggest that in the SJV, heat flux biases are strongly associated with irrigation during the growing season, while in the MMA, model-data residuals are limited to modest errors in the Bowen ratio and depend on land cover. Improving WRF’s representation of irrigation and land use, potentially through satellite remote sensing, may enhance surface flux simulation accuracy.</div></div>","PeriodicalId":50839,"journal":{"name":"Agricultural and Forest Meteorology","volume":"379 ","pages":"Article 111029"},"PeriodicalIF":5.7,"publicationDate":"2026-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146110944","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-03DOI: 10.1016/j.agrformet.2026.111049
Peirong Liu , Zhang Zhou , Guilin Wu , Xiaojuan Tong , Tao Zhang , Jingru Zhang , Fangyuan Wang , Dexiang Chen
Tropical forests store substantial carbon stocks and play important roles in biogeochemical carbon cycling. Understanding the drivers of carbon fluxes in tropical forests and how they respond to extreme events are crucial for predicting future global carbon dynamics. Utilizing a 12-year CO2 flux dataset and meteorological variables from a tropical montane rainforest ecosystem in southern China. This study assessed the effects of climatic drivers on the seasonal and interannual variations in gross primary productivity (GPP), ecosystem respiration (ER), and net ecosystem productivity (NEP), as well as the responses of carbon fluxes to extreme climate events. The ecosystem functioned as a strong carbon sink (NEP = 368 ± 121 g C m−2) across the study period. Both GPP and ER were generally higher in the wet season. Compared to the dry season, NEP values decreased by 18% during the wet season, primarily due to a temperature-induced increase in ER surpassing GPP. Annual GPP, ER, and NEP showed increasing trends of 32.32 g C m-2 year-1 (P < 0.1), 24.4 g C m-2 year-1 (P > 0.1), and 12.78 g C m-2 year-1 (P > 0.1), respectively. For seasonal fluxes, GPP was mainly controlled by solar-induced chlorophyll fluorescence (SIF), air temperature (Ta), and solar radiation (Rs); ER was predominantly influenced by the SIF and Ta; and NEP was primarily driven by Ta and Rs. On the interannual scale, Ta was the most important factor affecting GPP, ER, and NEP, followed by SIF, precipitation (PPT), and Rs. Extreme climate events, such as typhoons, significantly reduced GPP and NEP via physical pathways, while having a minimal effect on ER. Droughts notably enhanced GPP and ER (P < 0.05). In contrast, a severe drought in 2006 led to reductions in GPP, ER, and NEP of 11%, 12%, and 8%, respectively. Overall, this study addresses the lack of long-term research on CO2 fluxes in the tropical rainforest of China and will improve the understanding and prediction of the forest carbon dynamics.
热带森林蕴藏着丰富的碳储量,在生物地球化学碳循环中发挥着重要作用。了解热带森林碳通量的驱动因素以及它们如何对极端事件作出反应,对于预测未来全球碳动态至关重要。利用中国南方热带山地雨林生态系统12年CO2通量数据和气象变量。本研究评估了气候驱动因素对总初级生产力(GPP)、生态系统呼吸(ER)和净生态系统生产力(NEP)的季节和年际变化的影响,以及碳通量对极端气候事件的响应。在整个研究期间,生态系统作为一个强大的碳汇(NEP = 368±121 g C m−2)。GPP和ER在雨季普遍较高。与旱季相比,雨季NEP值下降了18%,这主要是由于温度引起的ER增加超过了GPP。年GPP、ER和NEP分别增加32.32 g C m-2 (P > 0.1)、24.4 g C m-2 (P > 0.1)和12.78 g C m-2 (P > 0.1)。在季节通量上,GPP主要受太阳诱导的叶绿素荧光(SIF)、气温(Ta)和太阳辐射(Rs)的控制;ER主要受SIF和Ta的影响;在年际尺度上,Ta是影响GPP、ER和NEP的最重要因子,其次是SIF、降水(PPT)和Rs。台风等极端气候事件通过物理途径显著降低GPP和NEP,而对ER的影响最小。干旱显著提高了GPP和ER (P < 0.05)。相比之下,2006年的严重干旱导致GPP、ER和NEP分别下降了11%、12%和8%。总体而言,该研究解决了中国热带雨林二氧化碳通量长期研究的不足,将提高对森林碳动态的认识和预测。
{"title":"Carbon exchange in a tropical montane rainforest: Annual budgets, drivers, and anomalies","authors":"Peirong Liu , Zhang Zhou , Guilin Wu , Xiaojuan Tong , Tao Zhang , Jingru Zhang , Fangyuan Wang , Dexiang Chen","doi":"10.1016/j.agrformet.2026.111049","DOIUrl":"10.1016/j.agrformet.2026.111049","url":null,"abstract":"<div><div>Tropical forests store substantial carbon stocks and play important roles in biogeochemical carbon cycling. Understanding the drivers of carbon fluxes in tropical forests and how they respond to extreme events are crucial for predicting future global carbon dynamics. Utilizing a 12-year CO<sub>2</sub> flux dataset and meteorological variables from a tropical montane rainforest ecosystem in southern China. This study assessed the effects of climatic drivers on the seasonal and interannual variations in gross primary productivity (GPP), ecosystem respiration (ER), and net ecosystem productivity (NEP), as well as the responses of carbon fluxes to extreme climate events. The ecosystem functioned as a strong carbon sink (NEP = 368 ± 121 g C m<sup>−2</sup>) across the study period. Both GPP and ER were generally higher in the wet season. Compared to the dry season, NEP values decreased by 18% during the wet season, primarily due to a temperature-induced increase in ER surpassing GPP. Annual GPP, ER, and NEP showed increasing trends of 32.32 g C m<sup>-2</sup> year<sup>-1</sup> (<em>P</em> < 0.1), 24.4 g C m<sup>-2</sup> year<sup>-1</sup> (<em>P</em> > 0.1), and 12.78 g C m<sup>-2</sup> year<sup>-1</sup> (<em>P</em> > 0.1), respectively. For seasonal fluxes, GPP was mainly controlled by solar-induced chlorophyll fluorescence (SIF), air temperature (<em>T</em><sub>a</sub>), and solar radiation (<em>R</em><sub>s</sub>); ER was predominantly influenced by the SIF and <em>T</em><sub>a</sub>; and NEP was primarily driven by <em>T</em><sub>a</sub> and <em>R</em><sub>s</sub>. On the interannual scale, <em>T</em><sub>a</sub> was the most important factor affecting GPP, ER, and NEP, followed by SIF, precipitation (PPT), and <em>R</em><sub>s</sub>. Extreme climate events, such as typhoons, significantly reduced GPP and NEP via physical pathways, while having a minimal effect on ER. Droughts notably enhanced GPP and ER (<em>P</em> < 0.05). In contrast, a severe drought in 2006 led to reductions in GPP, ER, and NEP of 11%, 12%, and 8%, respectively. Overall, this study addresses the lack of long-term research on CO<sub>2</sub> fluxes in the tropical rainforest of China and will improve the understanding and prediction of the forest carbon dynamics.</div></div>","PeriodicalId":50839,"journal":{"name":"Agricultural and Forest Meteorology","volume":"379 ","pages":"Article 111049"},"PeriodicalIF":5.7,"publicationDate":"2026-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146110714","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-03DOI: 10.1016/j.agrformet.2026.111054
Mael Aubry , Benjamin Renard , Thomas Opitz , Renan Le Roux , Marie Launay , Iñaki García de Cortázar-Atauri , Carina Furusho-Percot
Climate change is reshaping the agroclimatic conditions for wheat, taking some past decennial events to frequent climatic features, substantially increasing the probability of crop stress and yield loss. We propose a method using ecoclimatic indicators combined with probability models, continuous-time regression and copulas, to evaluate — in non-stationary context —the future climate suitability of common wheat in France expressed as the probability of exceeding past decennial thresholds. Under a high-emission scenario, our analysis identifies four emerging risks from 2050 onward: early heat stress and warm nights during the flag-leaf-to-anthesis stage, late warm nights from anthesis to grain maturity, and devernalisation. Precipitation- and humidity-related extremes during the vegetative phase are projected to slightly increase or stagnate, with strong regional and model-specific variability. Mild winters are likely to become a dominant climatic feature by century’s end, while late cold stress events decline sharply. In contrast, reproductive-phase heat stress intensifies markedly, becoming a dominant agroclimatic constraint by century’s end, whereas risks linked to excess moisture or precipitation decrease. Drought-related stress remains mostly stable, due to shorter phenological cycles. By century’s end, under high emission scenario, compound hazards —such as simultaneous drought and heat stress during key reproductive stages—are projected to become 3 to 6 times more frequent than in the historical baseline. Compound mild-winter and wet- or damp-condition events increase 2.5- to 12-fold. Regional disparities emerge: the English Channel coast and the Paris Basin appear comparatively less exposed to these climatic risks, positioning them as potential, though not risk-free, future refuges for wheat cultivation. A low-emission mitigation pathway would reduce the frequency of these risks by a factor of 2 to 6, and reduce interannual risk variability by up to 45% relative to high emissions. These findings highlight priority targets for adaptation and underscore the urgent need for mitigation to safeguard wheat production.
{"title":"From past exceptional extremes to frequent future risks: How climate change shapes the fate of common wheat in France","authors":"Mael Aubry , Benjamin Renard , Thomas Opitz , Renan Le Roux , Marie Launay , Iñaki García de Cortázar-Atauri , Carina Furusho-Percot","doi":"10.1016/j.agrformet.2026.111054","DOIUrl":"10.1016/j.agrformet.2026.111054","url":null,"abstract":"<div><div>Climate change is reshaping the agroclimatic conditions for wheat, taking some past decennial events to frequent climatic features, substantially increasing the probability of crop stress and yield loss. We propose a method using ecoclimatic indicators combined with probability models, continuous-time regression and copulas, to evaluate — in non-stationary context —the future climate suitability of common wheat in France expressed as the probability of exceeding past decennial thresholds. Under a high-emission scenario, our analysis identifies four emerging risks from 2050 onward: early heat stress and warm nights during the flag-leaf-to-anthesis stage, late warm nights from anthesis to grain maturity, and devernalisation. Precipitation- and humidity-related extremes during the vegetative phase are projected to slightly increase or stagnate, with strong regional and model-specific variability. Mild winters are likely to become a dominant climatic feature by century’s end, while late cold stress events decline sharply. In contrast, reproductive-phase heat stress intensifies markedly, becoming a dominant agroclimatic constraint by century’s end, whereas risks linked to excess moisture or precipitation decrease. Drought-related stress remains mostly stable, due to shorter phenological cycles. By century’s end, under high emission scenario, compound hazards —such as simultaneous drought and heat stress during key reproductive stages—are projected to become 3 to 6 times more frequent than in the historical baseline. Compound mild-winter and wet- or damp-condition events increase 2.5- to 12-fold. Regional disparities emerge: the English Channel coast and the Paris Basin appear comparatively less exposed to these climatic risks, positioning them as potential, though not risk-free, future refuges for wheat cultivation. A low-emission mitigation pathway would reduce the frequency of these risks by a factor of 2 to 6, and reduce interannual risk variability by up to 45% relative to high emissions. These findings highlight priority targets for adaptation and underscore the urgent need for mitigation to safeguard wheat production.</div></div>","PeriodicalId":50839,"journal":{"name":"Agricultural and Forest Meteorology","volume":"379 ","pages":"Article 111054"},"PeriodicalIF":5.7,"publicationDate":"2026-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146110713","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-02DOI: 10.1016/j.agrformet.2026.111051
Shijie Li , Guojie Wang , Shanlei Sun , Zefeng Chen , Matteo Mura , Jiao Lu , Qi Liu , Ji Li , Daniel Fiifi Tawia Hagan , Almudena García-García , Jian Peng
Land-atmosphere coupling (LAC) directly influences the occurrence of extreme climate events. Traditionally, the studies of LAC strength have primarily used soil moisture as a proxy for land conditions. However, recent research has highlighted the significant role of vegetation–atmosphere coupling (VC) in the evolution of extreme climate events through its regulation of the water and energy cycles. Despite this progress, the global patterns and driving mechanisms of VC remain unclear. In this study, the index with a clear physical meaning, ω, defined as the relationship between the canopy conductance (gc) and aerodynamic conductance (ga), was introduced to represent VC values. Long-term (1981–2018) global annual VC values were derived using two high-quality reanalysis datasets (ERA5 and MERRA2) based on two different gc models. Both gc models exhibited similar spatial distributions that the highest VC values in Arid regions, the lowest in Humid regions, and intermediate values in Transition zones. Results showed 38.84–61.98 % of global land with decreasing VC trend. An attribution analysis using a nonlinear machine learning approach revealed that leaf area index (LAI) and wind speed dominated the VC changes across different climate zones. An increase in LAI reduced VC strength, whereas enhanced wind speed increased VC values. LAI was the dominant factor influencing VC through transpiration regulation (i.e., gc) over Transition and Arid regions, while wind speed controlled VC variations via ga over Humid regions. Our study analyzed the spatiotemporal changes in VC values and their driving mechanisms across global land areas. These findings contribute to a deeper understanding of vegetation-climate feedback and its role in amplifying extreme climate events.
{"title":"Observed declining strength of vegetation-atmosphere coupling","authors":"Shijie Li , Guojie Wang , Shanlei Sun , Zefeng Chen , Matteo Mura , Jiao Lu , Qi Liu , Ji Li , Daniel Fiifi Tawia Hagan , Almudena García-García , Jian Peng","doi":"10.1016/j.agrformet.2026.111051","DOIUrl":"10.1016/j.agrformet.2026.111051","url":null,"abstract":"<div><div>Land-atmosphere coupling (LAC) directly influences the occurrence of extreme climate events. Traditionally, the studies of LAC strength have primarily used soil moisture as a proxy for land conditions. However, recent research has highlighted the significant role of vegetation–atmosphere coupling (VC) in the evolution of extreme climate events through its regulation of the water and energy cycles. Despite this progress, the global patterns and driving mechanisms of VC remain unclear. In this study, the index with a clear physical meaning, ω, defined as the relationship between the canopy conductance (g<sub>c</sub>) and aerodynamic conductance (g<sub>a</sub>), was introduced to represent VC values. Long-term (1981–2018) global annual VC values were derived using two high-quality reanalysis datasets (ERA5 and MERRA2) based on two different g<sub>c</sub> models. Both g<sub>c</sub> models exhibited similar spatial distributions that the highest VC values in Arid regions, the lowest in Humid regions, and intermediate values in Transition zones. Results showed 38.84–61.98 % of global land with decreasing VC trend. An attribution analysis using a nonlinear machine learning approach revealed that leaf area index (LAI) and wind speed dominated the VC changes across different climate zones. An increase in LAI reduced VC strength, whereas enhanced wind speed increased VC values. LAI was the dominant factor influencing VC through transpiration regulation (i.e., g<sub>c</sub>) over Transition and Arid regions, while wind speed controlled VC variations via g<sub>a</sub> over Humid regions. Our study analyzed the spatiotemporal changes in VC values and their driving mechanisms across global land areas. These findings contribute to a deeper understanding of vegetation-climate feedback and its role in amplifying extreme climate events.</div></div>","PeriodicalId":50839,"journal":{"name":"Agricultural and Forest Meteorology","volume":"379 ","pages":"Article 111051"},"PeriodicalIF":5.7,"publicationDate":"2026-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146110945","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-02DOI: 10.1016/j.agrformet.2026.111052
Towa Yamane , Masaru Inatsu , Jun Kawano , Takuto Sato , Hiroyuki Kusaka
This study aims to obtain fundamental information on birch pollen deposition data by field observation for the high-resolution, accurate pollen modeling. On the peak dispersal day in 2024, simple pollen collectors were installed just below and at three downwind points of an isolated birch tree line in Ebetsu, Hokkaido, Japan. Meteorological observations were also conducted at the site during the days. The birch pollen captured on slide glasses was imaged by a microscope. We automatically counted birch pollen grains by applying a machine learning algorithm You Only Look Once (YOLO) v5 to the images. The results suggested that the pollen count was highest in the point 200 m downstream from the tree line and diurnal variations were observed at all distances. The pollen counts in the downstream was correlated with air temperature with a statistical significance, but was correlated with wind speed with a marginal significance. The large-eddy simulation with the pollen advection supported the observation results, though the pollen deposition was more concentrated near the tree in the simulation.
本研究旨在通过野外观测获取白桦花粉沉积数据的基础信息,为高分辨率、准确的花粉建模提供依据。在2024年的传播高峰日,在日本北海道的Ebetsu,一个孤立的桦树线的下方和三个下风点安装了简单的花粉收集器。此外,天文台亦在该处进行气象观测。在载玻片上捕获的桦树花粉用显微镜成像。我们通过对图像应用机器学习算法You Only Look Once (YOLO) v5来自动计数桦树花粉颗粒。结果表明,花粉数量在距林木线下游200 m处最高,且各距离均有明显的日变化。下游花粉数与气温的相关性有统计学意义,与风速的相关性有边际显著性。具有花粉平流的大涡模拟支持观测结果,但模拟中花粉沉积更集中在树附近。
{"title":"Short-distance dispersion of birch pollen","authors":"Towa Yamane , Masaru Inatsu , Jun Kawano , Takuto Sato , Hiroyuki Kusaka","doi":"10.1016/j.agrformet.2026.111052","DOIUrl":"10.1016/j.agrformet.2026.111052","url":null,"abstract":"<div><div>This study aims to obtain fundamental information on birch pollen deposition data by field observation for the high-resolution, accurate pollen modeling. On the peak dispersal day in 2024, simple pollen collectors were installed just below and at three downwind points of an isolated birch tree line in Ebetsu, Hokkaido, Japan. Meteorological observations were also conducted at the site during the days. The birch pollen captured on slide glasses was imaged by a microscope. We automatically counted birch pollen grains by applying a machine learning algorithm You Only Look Once (YOLO) v5 to the images. The results suggested that the pollen count was highest in the point 200 m downstream from the tree line and diurnal variations were observed at all distances. The pollen counts in the downstream was correlated with air temperature with a statistical significance, but was correlated with wind speed with a marginal significance. The large-eddy simulation with the pollen advection supported the observation results, though the pollen deposition was more concentrated near the tree in the simulation.</div></div>","PeriodicalId":50839,"journal":{"name":"Agricultural and Forest Meteorology","volume":"379 ","pages":"Article 111052"},"PeriodicalIF":5.7,"publicationDate":"2026-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146110727","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-01DOI: 10.1016/j.agrformet.2026.111043
J.L. Exler , J. Skeeter , S.H. Knox , A. Christen , R.D. Moore
{"title":"Corrigendum to “Interannual climatic sensitivity of surface energy flux densities and evapotranspiration in a disturbed and rewetted ombrotrophic bog” [Agricultural and Forest Meteorology 367 (2025) 110501]","authors":"J.L. Exler , J. Skeeter , S.H. Knox , A. Christen , R.D. Moore","doi":"10.1016/j.agrformet.2026.111043","DOIUrl":"10.1016/j.agrformet.2026.111043","url":null,"abstract":"","PeriodicalId":50839,"journal":{"name":"Agricultural and Forest Meteorology","volume":"379 ","pages":"Article 111043"},"PeriodicalIF":5.7,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146110729","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-30DOI: 10.1016/j.agrformet.2026.111021
Sifang Feng , Jakob Zscheischler , Zengchao Hao , Jonas Jägermeyr , Christoph Müller , Emanuele Bevacqua
Spatial correlation between climate variables may modulate concurrent regional crop failures and reduce global crop production. However, the influence of spatial correlation in crop production fields on globally aggregated production remains poorly understood. Systematically addressing this gap using observed crop production is challenging, as such observational datasets typically suffer from limited sample sizes and/or coarse spatial information. Here, using gridded global simulations from the Global Gridded Crop Model Intercomparison Phase 3 (GGCMI3), we quantify how spatial correlation between regional crop productions influences global production across different spatial scales for maize, wheat, soybean, and rice. By employing the mean of crop production from multiple crop models forced with reanalysis climate data, we find minimal influence of the correlations between the productions of major breadbasket regions on global breadbasket-aggregated production. This aligns with the fact that global major breadbasket regions are generally non-large and distant from each other, whereas spatial correlations in the crop production field influence global crop production through correlations between small and nearby areas. The correlation between crop production of areas characterized by small spatial scales (100–1000 km) enhances extremely low (5th percentile) global production by about 0.9-1.1 standard deviation of the global production on average. This correlation effect at small spatial scales is less important for weaker extremes of low global crop production. Finally, crop model simulations forced with bias-corrected climate simulations often are not able to reproduce the correlation effects seen in crop model simulations forced with reanalysis climate data, suggesting that bias-corrected climate model input may degrade correlation effects in GGCMI3 crop simulations. These model-based results highlight that spatial correlations are a critical driver of global production risk, stressing the need for improved cross-regional processes representation in crop models to enhance future food security risk assessments.
{"title":"The influence of spatial correlations in crop production on global crop failures in model simulations","authors":"Sifang Feng , Jakob Zscheischler , Zengchao Hao , Jonas Jägermeyr , Christoph Müller , Emanuele Bevacqua","doi":"10.1016/j.agrformet.2026.111021","DOIUrl":"10.1016/j.agrformet.2026.111021","url":null,"abstract":"<div><div>Spatial correlation between climate variables may modulate concurrent regional crop failures and reduce global crop production. However, the influence of spatial correlation in crop production fields on globally aggregated production remains poorly understood. Systematically addressing this gap using observed crop production is challenging, as such observational datasets typically suffer from limited sample sizes and/or coarse spatial information. Here, using gridded global simulations from the Global Gridded Crop Model Intercomparison Phase 3 (GGCMI3), we quantify how spatial correlation between regional crop productions influences global production across different spatial scales for maize, wheat, soybean, and rice. By employing the mean of crop production from multiple crop models forced with reanalysis climate data, we find minimal influence of the correlations between the productions of major breadbasket regions on global breadbasket-aggregated production. This aligns with the fact that global major breadbasket regions are generally non-large and distant from each other, whereas spatial correlations in the crop production field influence global crop production through correlations between small and nearby areas. The correlation between crop production of areas characterized by small spatial scales (100–1000 km) enhances extremely low (5th percentile) global production by about 0.9-1.1 standard deviation of the global production on average. This correlation effect at small spatial scales is less important for weaker extremes of low global crop production. Finally, crop model simulations forced with bias-corrected climate simulations often are not able to reproduce the correlation effects seen in crop model simulations forced with reanalysis climate data, suggesting that bias-corrected climate model input may degrade correlation effects in GGCMI3 crop simulations. These model-based results highlight that spatial correlations are a critical driver of global production risk, stressing the need for improved cross-regional processes representation in crop models to enhance future food security risk assessments.</div></div>","PeriodicalId":50839,"journal":{"name":"Agricultural and Forest Meteorology","volume":"379 ","pages":"Article 111021"},"PeriodicalIF":5.7,"publicationDate":"2026-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146080637","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Monitoring of photosynthetic activity is essential for understanding forest carbon dynamics, particularly in structurally stable but physiologically dynamic ecosystems such as subtropical evergreen broadleaf forests. This study investigated the seasonal and diurnal dynamics of far-red and red solar-induced chlorophyll fluorescence (SIF), gross primary productivity (GPP), and related metrics in a subtropical evergreen broadleaf forest in Okinawa, Japan, on the basis of ground-based observations from 2020 to 2022. Far-red SIF consistently exhibited stronger and more stable correlations with GPP than red SIF, especially under overcast conditions and at daily temporal resolution. However, a significant environmental divergence was observed in the efficiency metrics. Environmental binning analyses revealed that light-use efficiency (LUE) responded strongly to changes in vapor pressure deficit (VPD), whereas SIF yield exhibited much weaker sensitivity. Random forest analysis further supported this divergence, showing a distinct, time-dependent sensitivity of SIF yield and LUE to VPD. Consistent with these environmental sensitivities, diurnal patterns showed that a pronounced inconsistency emerged at the efficiency level: the relationship between far-red SIF yield and LUE was generally weak or non-significant, indicating asynchronous regulation of fluorescence efficiency and carbon assimilation. Diurnal analyses showed that this decoupling could become more pronounced under certain conditions, such as during the afternoon. These findings refine the interpretation of SIF-based indicators in dense evergreen canopies and underscore the importance of the efficiency-level asynchronous recovery for improving SIF-based GPP models in subtropical ecosystems.
{"title":"The efficiency-level inconsistency of the SIF–GPP relationship in a subtropical evergreen forest in Okinawa, Japan","authors":"Junjie Fu , Tomomichi Kato , Tomoki Morozumi , Kazuho Matsumoto , Shingo Taniguchi , Masahito Ueyama , Kanokrat Buareal , Tatsuya Miyauchi , Naohisa Nakashima , Tomoko Kawaguchi Akitsu","doi":"10.1016/j.agrformet.2026.111050","DOIUrl":"10.1016/j.agrformet.2026.111050","url":null,"abstract":"<div><div>Monitoring of photosynthetic activity is essential for understanding forest carbon dynamics, particularly in structurally stable but physiologically dynamic ecosystems such as subtropical evergreen broadleaf forests. This study investigated the seasonal and diurnal dynamics of far-red and red solar-induced chlorophyll fluorescence (SIF), gross primary productivity (GPP), and related metrics in a subtropical evergreen broadleaf forest in Okinawa, Japan, on the basis of ground-based observations from 2020 to 2022. Far-red SIF consistently exhibited stronger and more stable correlations with GPP than red SIF, especially under overcast conditions and at daily temporal resolution. However, a significant environmental divergence was observed in the efficiency metrics. Environmental binning analyses revealed that light-use efficiency (LUE) responded strongly to changes in vapor pressure deficit (VPD), whereas SIF yield exhibited much weaker sensitivity<strong>.</strong> Random forest analysis further supported this divergence, showing a distinct, time-dependent sensitivity of SIF yield and LUE to VPD. Consistent with these environmental sensitivities, diurnal patterns showed that a pronounced inconsistency emerged at the efficiency level: the relationship between far-red SIF yield and LUE was generally weak or non-significant, indicating asynchronous regulation of fluorescence efficiency and carbon assimilation. Diurnal analyses showed that this decoupling could become more pronounced under certain conditions, such as during the afternoon. These findings refine the interpretation of SIF-based indicators in dense evergreen canopies and underscore the importance of the efficiency-level asynchronous recovery for improving SIF-based GPP models in subtropical ecosystems.</div></div>","PeriodicalId":50839,"journal":{"name":"Agricultural and Forest Meteorology","volume":"379 ","pages":"Article 111050"},"PeriodicalIF":5.7,"publicationDate":"2026-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146071842","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-28DOI: 10.1016/j.agrformet.2026.111034
Shenning Wang , Ren Li , Tonghua Wu , Junjie Ma , Wenhao Liu , Shuhua Yang , Yizhen Du , Yao Xiao , Xiaodong Wu , Guojie Hu , Jimin Yao , Shengfeng Tang , Xiaofan Zhu , Jianzong Shi , Yongping Qiao
Soil hydrothermal processes in permafrost regions are critical for land-atmosphere exchange but are challenging to simulate accurately in models, largely due to the parameterization of unfrozen water content. This study evaluated 11 freezing-point depression schemes, derived from combinations of three soil water characteristic curves (SWCCs) and four soil matric potential schemes, using CLM5.0 at six sites across the Arctic and Qinghai-Tibet Plateau (QTP). Results showed regionally dependent optimal schemes. For soil temperature, a combined effective porosity and cryosuction scheme (TEST3) reduced the RMSE by 0.51–0.52°C (7.1–8.3%) in the Arctic, while a cryosuction scheme (TEST10) was best on the QTP, reducing RMSE by 0.04–0.06°C. For soil moisture, a Van Genuchten SWCC scheme with effective porosity (TEST5) reduced RMSE by up to 0.018 m3/m3 (13.2%) in the Arctic, and TEST4/TEST5 performed best on the QTP. The explicit parameterization of residual water content in Brooks & Corey and Van Genuchten SWCCs was a key mechanism, correcting the default scheme's large soil moisture bias by up to 53% during freezing. Cryosuction increased unfrozen water, while effective porosity decreased it. However, model structural limitations caused unreliable matric potential output during freezing. Persistent biases at specific sites were attributed to inaccurate soil texture data, unaccounted lateral flow, and insufficient snow insulation representation. This study highlights the regional applicability of schemes and provides critical insights for improving permafrost simulations.
{"title":"Evaluating the impact of different freezing-point depression equations on permafrost hydrothermal processes in the Arctic and Qinghai-Tibet Plateau with CLM5.0","authors":"Shenning Wang , Ren Li , Tonghua Wu , Junjie Ma , Wenhao Liu , Shuhua Yang , Yizhen Du , Yao Xiao , Xiaodong Wu , Guojie Hu , Jimin Yao , Shengfeng Tang , Xiaofan Zhu , Jianzong Shi , Yongping Qiao","doi":"10.1016/j.agrformet.2026.111034","DOIUrl":"10.1016/j.agrformet.2026.111034","url":null,"abstract":"<div><div>Soil hydrothermal processes in permafrost regions are critical for land-atmosphere exchange but are challenging to simulate accurately in models, largely due to the parameterization of unfrozen water content. This study evaluated 11 freezing-point depression schemes, derived from combinations of three soil water characteristic curves (SWCCs) and four soil matric potential schemes, using CLM5.0 at six sites across the Arctic and Qinghai-Tibet Plateau (QTP). Results showed regionally dependent optimal schemes. For soil temperature, a combined effective porosity and cryosuction scheme (TEST3) reduced the RMSE by 0.51–0.52°C (7.1–8.3%) in the Arctic, while a cryosuction scheme (TEST10) was best on the QTP, reducing RMSE by 0.04–0.06°C. For soil moisture, a Van Genuchten SWCC scheme with effective porosity (TEST5) reduced RMSE by up to 0.018 m<sup>3</sup>/m<sup>3</sup> (13.2%) in the Arctic, and TEST4/TEST5 performed best on the QTP. The explicit parameterization of residual water content in Brooks & Corey and Van Genuchten SWCCs was a key mechanism, correcting the default scheme's large soil moisture bias by up to 53% during freezing. Cryosuction increased unfrozen water, while effective porosity decreased it. However, model structural limitations caused unreliable matric potential output during freezing. Persistent biases at specific sites were attributed to inaccurate soil texture data, unaccounted lateral flow, and insufficient snow insulation representation. This study highlights the regional applicability of schemes and provides critical insights for improving permafrost simulations.</div></div>","PeriodicalId":50839,"journal":{"name":"Agricultural and Forest Meteorology","volume":"379 ","pages":"Article 111034"},"PeriodicalIF":5.7,"publicationDate":"2026-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146072718","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-27DOI: 10.1016/j.agrformet.2026.111035
Lu Liu , Yunjun Yao , Qingxin Tang , Xueyi Zhang , Yufu Li , Joshua B. Fisher , Jiquan Chen , Jia Xu , Xiaotong Zhang , Ruiyang Yu , Zijing Xie , Jing Ning , Jiahui Fan , Luna Zhang
The latent heat of evapotranspiration (LE) is a vital element of agricultural water resources; accurately estimating cropland LE at a fine spatial resolution is crucial for monitoring agricultural drought and estimating crop water requirements. In this study, we propose a shortwave infrared-transformed reflectance (STR)-and ensemble Kalman filter (EnKF)-based Priestley–Taylor (STR–EnKF–PT) model to simulate daily cropland LE using Sentinel-2 data. To evaluate the STR–EnKF–PT model’ performance, we conducted an assessment using ground observations derived from 10 eddy covariance (EC) sites situated in various regions of the United States over the two-year period from 2019 through 2020.The results revealed that STR–EnKF–PT yielded better performance than the competing methods did at four validation sites; additionally, the coefficient of determination (R2) was 0.54∼0.84 at the 99 % confidence level, the root-mean-square error (RMSE) was 26.1∼38.0 W/m2, the Kling–Gupta efficiency (KGE) value was 0.69∼0.91, and the bias was -16.3∼9.4 W/m2. Crucially, the ensemble system demonstrated robust probabilistic forecasting capabilities across different validation sites, with an excellent mean reliability score of 0.0010, a mean continuous ranked probability score (CRPS) of 29.91 W/m2, and appropriate spread-error relationships with a mean ratio of 1.239, providing reliable probability distributions of LE forecasts beyond deterministic estimates. STR–EnKF–PT was then used to depict the spatial patterns of cropland LE at a 20-m resolution in six different regions across the United States, and the results revealed that it is possible to accurately distinguish the LE status of cultivated land. One innovation is the use of soil moisture (SM) constraints derived from the STR to achieve high-resolution (20-m) cropland LE estimation. Furthermore, the incorporation of EnKF significantly enhances the estimated accuracy of the STR–EnKF–PT model and enables reliable probabilistic forecasting. This approach has significant practical implications for achieving the efficient utilization of cropland irrigation water and agricultural risk management processes.
{"title":"Cropland evapotranspiration based on Sentinel-2 shortwave infrared data and ensemble Kalman filter","authors":"Lu Liu , Yunjun Yao , Qingxin Tang , Xueyi Zhang , Yufu Li , Joshua B. Fisher , Jiquan Chen , Jia Xu , Xiaotong Zhang , Ruiyang Yu , Zijing Xie , Jing Ning , Jiahui Fan , Luna Zhang","doi":"10.1016/j.agrformet.2026.111035","DOIUrl":"10.1016/j.agrformet.2026.111035","url":null,"abstract":"<div><div>The latent heat of evapotranspiration (LE) is a vital element of agricultural water resources; accurately estimating cropland LE at a fine spatial resolution is crucial for monitoring agricultural drought and estimating crop water requirements. In this study, we propose a shortwave infrared-transformed reflectance (STR)-and ensemble Kalman filter (EnKF)-based Priestley–Taylor (STR–EnKF–PT) model to simulate daily cropland LE using Sentinel-2 data. To evaluate the STR–EnKF–PT model’ performance, we conducted an assessment using ground observations derived from 10 eddy covariance (EC) sites situated in various regions of the United States over the two-year period from 2019 through 2020.The results revealed that STR–EnKF–PT yielded better performance than the competing methods did at four validation sites; additionally, the coefficient of determination (R<sup>2</sup>) was 0.54∼0.84 at the 99 % confidence level, the root-mean-square error (RMSE) was 26.1∼38.0 W/m<sup>2</sup>, the Kling–Gupta efficiency (KGE) value was 0.69∼0.91, and the bias was -16.3∼9.4 W/m<sup>2</sup>. Crucially, the ensemble system demonstrated robust probabilistic forecasting capabilities across different validation sites, with an excellent mean reliability score of 0.0010, a mean continuous ranked probability score (CRPS) of 29.91 W/m<sup>2</sup>, and appropriate spread-error relationships with a mean ratio of 1.239, providing reliable probability distributions of LE forecasts beyond deterministic estimates. STR–EnKF–PT was then used to depict the spatial patterns of cropland LE at a 20-m resolution in six different regions across the United States, and the results revealed that it is possible to accurately distinguish the LE status of cultivated land. One innovation is the use of soil moisture (SM) constraints derived from the STR to achieve high-resolution (20-m) cropland LE estimation. Furthermore, the incorporation of EnKF significantly enhances the estimated accuracy of the STR–EnKF–PT model and enables reliable probabilistic forecasting. This approach has significant practical implications for achieving the efficient utilization of cropland irrigation water and agricultural risk management processes.</div></div>","PeriodicalId":50839,"journal":{"name":"Agricultural and Forest Meteorology","volume":"379 ","pages":"Article 111035"},"PeriodicalIF":5.7,"publicationDate":"2026-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146072720","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}