Abstract Predicting terrestrial carbon, C, budgets and carbon‐climate feedbacks strongly relies on our ability to accurately model interactions between vegetation, C water cycles, the atmosphere. However, fluxes simulated by global, process‐based biosphere models (TBMs) remain subject large uncertainties, partly due unknown or poorly calibrated parameters. This is because TBMs have not routinely been confronted against cycle related datasets within a statistical data assimilation (DA)...

Abstract Earth System Models (ESMs) continue to diagnose a wide range of carbon budgets for each level global warming. Here, we present emergent constraints on the budget as function warming, which combine available ESM historical simulations and future projections scenarios, with observational estimates warming anthropogenic CO 2 emissions day. We estimate mean likely ranges cumulative Paris targets 1.5 °C 812 [691, 933] PgC 1048 [881, 1216] PgC, are more than 10% larger ensemble values...

Due to human activities, large volumes of soils are contaminated with organic pollutants such as polycyclic aromatic hydrocarbons, and very often by metallic well. Multipolluted therefore a key concern for remediation. This work presents long-term evaluation the fate environmental impact contaminants an industrially polluted soil under natural plant-assisted conditions. A field trial was followed four years according six treatments in replicates: unplanted, planted alfalfa or without...

Abstract. Land-surface models (LSMs) are crucial components of the Earth system (ESMs) that used to make coupled climate–carbon cycle projections for 21st century. The Joint UK Land Environment Simulator (JULES) is land-surface model in climate and weather forecast Met Office. JULES also extensively offline as a impacts tool, forced with climatologies into future. In this study, automatically differentiated respect parameters using commercial software from FastOpt, resulting an analytical...

Abstract The rate at which land surface soils dry following rain events is an important feature of terrestrial models. It determines, for example, the water availability vegetation, occurrences droughts, and heat exchanges. As such, soil moisture (SSM) “drydowns,” i.e., SSM temporal dynamics a significant rainfall event, are particular interest when evaluating calibrating models (LSMs). By investigating drydowns, characterized by exponential decay time scale τ , we aim to improve...

Abstract. Land surface modellers need measurable proxies to constrain the quantity of carbon dioxide (CO2) assimilated by continental plants through photosynthesis, known as gross primary production (GPP). Carbonyl sulfide (COS), which is taken up leaves their stomates and then hydrolysed photosynthetic enzymes, a candidate GPP proxy. A former study with ORCHIDEE land model used fixed ratio COS uptake CO2 normalised respective ambient concentrations for each vegetation type (leaf relative...

Abstract Understanding the response of plant respiration to climate change is key determining whether global land carbon sink continues into future or declines. Most vegetation models use a classical growth-maintenance approach, which predicts that nocturnal controlled by temperature only. However, recently published observations show decline through night even at constant temperature, these cannot reproduce. Here we assess role respiratory substrates in this observed evaluating an...

Abstract Peatlands at high latitudes have accumulated >400 Pg carbon (C) because saturated soil and cold temperatures suppress C decomposition. This substantial amount of in Arctic Boreal peatlands is potentially subject to increased decomposition if the water table (WT) decreases due climate change, including permafrost thaw‐related drying. Here, we optimize a version Organizing Carbon Hydrology In Dynamic Ecosystems model (ORCHIDEE‐PCH4) using site‐specific observations investigate...

Abstract. Carbonyl sulfide (COS) is an atmospheric trace gas of interest for C cycle research because COS uptake by continental vegetation strongly related to terrestrial gross primary productivity (GPP), the largest and most uncertain flux in CO2 budgets. However, use as additional tracer GPP, accurate quantification exchange soils also needed. At present, budget unbalanced globally, with total estimates from oxic anoxic that vary between −409 −89 GgS yr−1. This uncertainty hampers...

Machine learning models have emerged as powerful tools for simulating Earth system processes. Following their successful application in capturing atmospheric evolution medium-range weather forecasts, attention has increasingly shifted towards other components of the system, such marine and land environments. This interest is further driven by potential to enhance forecasting capabilities beyond medium range. frameworks offer remarkable flexibility integrating these model achieve a coherent...

Abstract. Land surface temperature (LST) plays an essential role in water and energy exchanges between the Earth's atmosphere. Recent advancements high-quality satellite-derived LST data land assimilation systems present a unique opportunity to bridge gap global observational models (LSMs) better constrain budgets changing climate. In this vein, study focuses on of ESA CCI-LST product into ORCHIDEE LSM (the continental part Institut Pierre-Simon Laplace Earth system model) with aim...

Abstract. A comprehensive understanding and an accurate modelling of the terrestrial carbon cycle, are paramount importance to improve projections global cycle more accurately gauge its impact on climate systems. Land Surface Models, which have become important component weather applications, simulate key aspects such as photosynthesis respiration. These models rely parameterisations that necessitate be carefully calibrated. In this study we explore assimilation atmospheric CO2 concentration...

Hydrological modeling has entered a new era in recent years, largely driven by the curation of extensive datasets and availability open-source machine learning libraries. While traditional physically based models have been key to improving our understanding hydrological systems establishing early warning systems, they often face challenges such as high computational costs requiring simplifications complex processes. Conversely, methods, despite potential pitfalls generating unphysical...

Abstract Given the ever increasing spatial resolution of climate models and significant role lakes on regional climate, it becomes important to represent water bodies in models. Such developments have started IPSL (Institut Pierre Simon Laplace) model its land surface component, ORganizing Carbon Hydrology In Dynamic Ecosystems (ORCHIDEE), with Freshwater Lake model, FLake. To answer questions raised by these new developments, such as lake differentiation related parameters, we analyze...

Abstract. Land–atmosphere (L–A) interactions encompass the co-evolution of land surface and overlying planetary boundary layer, primarily during daylight hours. However, many studies have been conducted using monthly or entire-day mean time series due to lack subdaily data. It is unclear whether inclusion nighttime data alters assessment L–A coupling obscures interactive processes. To address this question, we generate (M), (E), daytime-only (D) based on ERA5 (5th European Centre for...

Soil moisture plays a key role in water, carbon and energy exchanges between the land surface atmosphere. Therefore, better representation of this variable Land-Surface Models (LSMs) used climate modelling could significantly reduce uncertainties associated with future predictions. In study, ESA-CCI soil (SM) combined product (v4.2) has been confronted to simulated top-first layers/cms ORCHIDEE LSM (the continental part IPSL Earth System Model) for years 2008-2016, evaluate its potential...

<p>Water potential directly controls the function of leaves, roots and microbes, water gradients drive flows throughout soil-plant-atmosphere continuum. Notwithstanding its clear relevance for many ecosystem processes, soil is rarely measured in-situ, plant observations are generally discrete, sparse, not yet aggregated into accessible databases. These gaps limit our conceptual understanding biophysical responses to moisture stress inject large uncertainty hydrologic land...

Boreal forests absorb a significant amount of atmospheric CO2 through gross primary production (GPP), representing about 20% the global GPP. However, direct observations GPP over whole boreal region are not available as plant photosynthetic rate cannot be measured at scales larger than leaf scale. At large scales, Land Surface Models (LSMs) can simulate but lack measurements makes it challenging to evaluate and improve representation in LSMs. In addition, highly sensitive environmental...

Abstract. Greenland ice sheet mass loss continues to accelerate as global temperatures increase. The surface albedo of the determines amount absorbed solar energy, which is a key factor in driving snow and melting. Satellite-retrieved allows us compare optimise modelled over entirety sheet. We parameters scheme ORCHIDEE (Organizing Carbon Hydrology Dynamic Ecosystems) land model for 3 random years taken 2000–2017 period validate remaining years. In particular, we want improve at edges sheet,...

Abstract. Land surface modelers need measurable proxies to constrain the quantity of carbon dioxide (CO2) assimilated by continental plants through photosynthesis, known as Gross Primary Production (GPP). Carbonyl sulfide (COS), which is taken up leaves their stomates and then hydrolysed photosynthetic enzymes, a candidate GPP proxy. A former study with ORCHIDEE land model used fixed ratio COS uptake CO2 normalized respective ambient concentrations for each vegetation type (Leaf Relative...

Abstract. Land-surface models (LSMs) are crucial components of the Earth System Models (ESMs) which used to make coupled climate-carbon cycle projections for 21st century. The Joint UK Land Environment Simulator (JULES) is land-surface model in climate and weather forecast Met Office. In this study, JULES automatically differentiated using commercial software from FastOpt, resulting an analytical gradient, or adjoint, model. Using adJULES parameter estimation system has been developed,...

Abstract. The role of the land carbon cycle in climate change remains highly uncertain. A key source projection spread is related to assumed response photosynthesis warming, especially tropics. optimum temperature for determines whether warming positively or negatively impacts photosynthesis, thereby amplifying suppressing CO2 fertilisation under CO2-induced global warming. Land models have been extensively calibrated against local eddy flux measurements, but this has not previously clearly...

Abstract. Current climate warming is accelerating mass loss from glaciers and ice sheets. In Greenland, the rates of changes are now dominated by in surface balance (SMB) due to increased melting. To improve future sea-level rise projections, it therefore critical have an accurate estimate SMB, which depends on representation processes occurring within snowpack. The snow scheme (ES) implemented land model ORCHIDEE has not yet been adapted ice-covered areas. Here, we present preliminary...

Abstract. Current climate warming is accelerating mass loss from glaciers and ice sheets. In Greenland, the rates of changes are now dominated by in surface balance (SMB) due to increased melting. To improve future sea-level rise projections, it therefore critical have an accurate estimate SMB, which depends on representation processes occurring within snowpack. The Explicit Snow (ES) scheme implemented land model Organising Carbon Hydrology Dynamic Ecosystems (ORCHIDEE) has not yet been...