Institut Pierre-Simon Laplace

Ten years of measurements (2012-2022) of the atmospheric composition at Saclay/SIRTA observatory in the Ile de France region as part of ICOS and ACTRIS

Abstract. CO2 is the main contributor to global warming, and cities now account for more than two-thirds of emissions of this gas. Atmospheric observatories located on the outskirts of cities are therefore important facilities for measuring the impact on atmospheric composition o...

Volatile organic compounds and their role in secondary aerosol chemistry in a cold and dark urban environment

Abstract. Wintertime PM2.5 pollution is a longstanding issue in the urban subarctic environment such as Fairbanks, Alaska. While previous studies suggest that aldehydes may serve as precursors of S(IV) species in aerosols, the role of volatile organic compound (VOC) emissions in...

Including the triple isotopic composition of dissolved oxygen in the ocean into the iLOVECLIM model (version 1.1.7): development and evaluation

Abstract. Contributing around half of the oxygen produced on Earth, marine photosynthetic production is one of the main mechanisms for carbon fixation, with a central role in the oxygen cycle. The triple isotopic composition of atmospheric oxygen (17Δ), measured in ice cores, pro...

Urban-to-downwind variations in aerosol composition and optical properties in the Paris urban plume from coordinated airborne and ground-based observations

Abstract. Aerosols play a critical role in Earth’s climate, but substantial evolution in their physicochemical properties after emission introduces uncertainties in predicting their climate impacts. Observational constraints on how aging modifies aerosol properties remain limited...

Tropospheric Ozone Assessment Report II: Past and present tropospheric ozone using satellite observations

Satellite observations enable global assessments of ozone in the free troposphere, yet uncertainties in earlier records limited the first Tropospheric Ozone Assessment Report's (TOAR-I) confidence in regional distributions and, especially, decadal trends. Here, we leverage longer...

Tropospheric Ozone Assessment Report II: Overview

Abstract The International Global Atmospheric Chemistry (IGAC) Tropospheric Ozone Assessment Report Phase II (TOAR-II) provides an updated, comprehensive assessment of the global distribution, burden and trends of tropospheric ozone, building on the foundation established by TOAR...

Seasonal cycle in surface seawater isotopic composition

Abstract. Data of stable isotopologs of water in the quality-controlled CISE-LOCEAN database provide an unprecedented sampling of the surface Atlantic Ocean and the southwest Indian Ocean. This investigation of δ18O, δ2H and deuterium excess (d-excess) in surface sea water indica...

The enhanced capabilities of mid-infrared limb emission sounding to observe stratospheric aerosol injection geoengineering

Abstract. Using a model-based pseudo-reality (PR) future scenario and realistic pseudo-observations (POs) representative for a proposed satellite mission concept (CAIRT – the Changing-Atmosphere Infra-Red Tomography explorer), we analyse the capabilities of a high-spectral-resolu...

Resolution Dependence of the Climate Feedback Parameter in Km‐Scale Climate Models

Abstract Global storm‐resolving models (GSRMs) provide new opportunities to investigate the climate response to warming with explicitly resolved deep convection. However, the limited number of existing studies has so far precluded the systematic assessment of similarities and dif...

Benchmarking a new urban scheme in the ORCHIDEE 2.2 land surface model

Urban areas change natural surface energy and water balances, yet some land surface models still represent cities as natural surfaces. In this study, we present the development of a one-tile urban scheme for the ORCHIDEE land surface model, designed to improve the representation...

Validation of EarthCARE CPR reflectivity using the ACTRIS cloud radar network

The Earth Cloud, Aerosol, and Radiation Explorer (EarthCARE) satellite carries a cloud profiling radar (CPR) designed to observe global cloud properties. In this study, we assess the calibration of CPR reflectivity profiles by comparing them with seven calibrated ground-based clo...

JuRa: The Juventas Radar on Hera Mission to Probe Internal Structure of Didymos and Dimorphos Asteroids

Abstract JuRa, the Juventas Radar, is the sounding radar of the Hera/ESA mission on cruise to the asteroid Didymos and its moon, Dimorphos. In 2027, it will, for the first time, do direct observation of the internal structure of an asteroid for the benefit of both science and pla...

Evidence for the impact of fire activity on daily variations of IASI mid-tropospheric CO 2 anomalies at 8–11 km over South America: a pyroconvective fingerprint

Biomass burning is a major, highly variable source of atmospheric CO 2 , but its impact on the free troposphere remains difficult to quantify because of uncertainties in injection heights and transport. In the tropics, intense fires can trigger pyroconvective plumes that loft com...

On the Timescales of Atmospheric Adjustments to Contrail Cirrus Formation

Abstract Condensation trails (contrails) that evolve into contrail cirrus may constitute the largest contribution to aviation's climate impact. However the strength and timescales of the adjustments of the upper atmospheric water budget to contrail formation are poorly known. Tha...

Space‐Based Observation of Decadal Variations of Ammonium Sulfate Aerosols Over Northern China

Abstract The concentrations of ammonium sulfate, an important component of secondary inorganic aerosols, have dropped substantially in the North China Plain (NCP) over the past decade. However, current understanding of its variations is limited by the small number of ground‐based...

Beyond wind-induced upwelling: diverse drivers of future productivity in eastern boundary upwelling systems

Abstract. Eastern Boundary Upwelling Systems (EBUS) contribute disproportionately to global marine productivity and fisheries, yet their response to climate change remains poorly understood. Given the essential ecosystem services they support, improving projections of future EBUS...

Dry snow initialization and densification over the Greenland and Antarctic ice sheets in the ORCHIDEE land surface model

Abstract. Accurate modeling of the snowpack over ice sheets is essential for quantifying their surface mass balance contribution and their resulting impact on sea level rise. The snowpack evolution is largely governed by surface climate but also by internal processes such as dens...