NASA EVS Atmospheric Tomography Mission (ATom) provided unprecedented and rich measurements for aerosols, clouds, precursor gases, and meteorological fields over global oceans. In this study, we aim to address the AeroCom multi-model simulations of aerosols, new particle formation, and clouds constrained by ATom measurements, as well as measurements from various satellites and ground platforms. The study will cover remote regions over the Pacific, Atlantic, and Southern Oceans from near surface to ~12 km altitude and covers four seasons.

This experiment aims to perform a multi-model evaluation against reanalysis meteorological fields combined with ground-based observations of aerosol properties in a trajectory-based Lagrangian framework. The representation of source and transport dependence of aerosols to different regions will be examined.

Our previous study has shown that cloud plays much more important roles on the surface dimming/brightening trends. Aerosol direct radiative effects is only obvious under clear sky conditions. Big questions need to be addressed: (1) What causes the cloud trend? (2) How much is the change of cloud mediated by aerosols through aerosol-cloud-radiation interaction? (3) How does climate change affect the cloud and aerosol trends and their interactions?

Experiments for dust models are proposed to estimate the contribution of land use to dust emission, deposition, and optical properties. In addition a sensitivity study related to the threshold of wind erosion is proposed. Multi-models comparison with observations will provide an envelope of uncertainties.. A detailed description can be found here: Specifications

Motivation: The Asian monsoon system is a major component in Earth’s climate. Given rapid population and economic growth across the Asian monsoon region, serious concern has emerged that coupling between the monsoon system and surface emissions is having increasingly significant effects not only on regional air quality but also on global atmospheric composition. This proposed activity represents a coordinated modeling and analysis effort among the AeroCom, CCMI, and ACAM communities to study interactions between Asian air pollution and the monsoon system.

Building on the Phase II experiments this effort will support the interpolation of consolidated flight track points from high-temporal resolution model output to minimise the large sampling biases that would otherwise be present.

Note, we are now only requesting a single year of simulation for the mandatory Tier 1 submissions. Tier 2 submissions are also welcome.

Smoke aerosols can adversely affect surface air quality and visibility near emission sources and even hundreds to thousands of km downwind, and thus create health and aviation hazards. They also have impacts on air temperature, cloud properties and precipitation. The atmospheric composition of smoke aerosols depends not only on the emitted mass, but also on the injection height. This is especially true for large boreal forest fires that often emit smoke above planetary boundary layer (PBL) into the free troposphere and even the lower stratosphere.

Dust radiative forcing from reconstructed dust changes since pre-industrial times (DURF)

This experiment will investigate the impact of dust from the prominent dust source regions, and the source-receptor relationships over land and remote ocean regions. In addition to the previous AeroCom experiments which focus on the regions where dust amount is significant, this proposed study will also analyze the source-receptor relationships over more extended regions including Arctic, Antarctic, Tibetan Plateau, and oceanic areas.

The main aim of the historical experiment is to understand regional trends in aerosol distribution from 1850 to 2015 and make an AeroCom reference aerosol distribution dataset (1850-2015). This experiment will also quantify the aerosol impact on TOA and surface forcing with a main emphasis on the direct aerosol effect. We underscore that the CMIP6 CEDS emissions must be used for the historical simulations. Simulations can either be performed with fixed sea-surface temperature (SSTs), historically evolving SSTs or fixed meteorology for one year.

A short description (about a paragraph) should go here. A detailed description can be found here: INSITU_AeroComPIII_description.pdf

Direct radiative forcing due to anthropogenic black carbon (BC) is highly uncertain but best estimates suggest a large positive effect (+0.71 [+0.08, +1.27] W m-2). The uncertainty in the total forcing is due to large uncertainties in the atmospheric burden of BC and its radiative properties. The uncertainty in the burden is in-turn due to the uncertainty in emissions (7500 [2000, 29000] Gg yr-1) and lifetime (removal rates). In comparison with the available observations GCMs tend to under-predict absorption near source (e.g.

The goal is to understand what factors affect the magnitude of the aerosol-cloud interactions in several different model systems. The indirect radiative effect of aerosols on clouds (ACI, or ERF_ACI according to the IPCC) is the largest uncertainty in climate forcing over the historical record.

As part of the CTRL2016 experiment, we propose a remote sensing evaluation of models using a variety of satellite sensors (MODIS, PARASOL, AATSR) and ground networks (AERONET, SKYNET). The only requirement to contribute to this experiment is high-frequency (3-hourly) output of a few model fields (such as AOD).

Airborne deposition of mineral dust and associated nutrients could fertilize ocean ecosystems and influence ocean biogeochemical cycles and climate. Model simulations of dust deposition depend strongly on the highly parameterized representations of a suite of dust processes with little constraints. In recent years, several intensive field campaigns have acquired new datasets of microphysical and optical properties of African dust.

The upper troposphere/lower stratosphere (UTLS) is a crucial region for Earth's climate, where changes of aerosol loading and composition can have a direct impact on the amount of radiation absorbed and emitted.

Understanding of how changes in aerosol particles affect clouds remains one of the most challenging and persistent problems in atmospheric science. Aerosol-Cloud Interactions (ACI) are hard to constrain as it operates at scales much smaller than the scales resolved by Earth System Models (ESMs). To rub salt into the wound, lack of suitable observations at globally relevant spatial scales with which to challenge the models hampers our capacity of validating ESM estimates of ACI impacts.