The AeroCom phase III experiments were initiated in March 2015 to expand earlier work.

Details of experiment design, priorities, requested output, and timeline are described in the linked documents below and also in the priority tables.

Files from AeroCom phase III experiments should be found on the aerocom-users server under

/metno/aerocom-users-database/AEROCOM-PHASE-III/{model}

For submissions of data to any experiment described below, please follow the instructions given here

The currently proposed and on-going AeroCom Phase III model experiments require to use the same emission datasets for all simulations:

• Anthropogenic emissions: Community Emission Data System (CEDS) for CMIP6, currently available for 1750-2014
• Biomass burning emissions: CEDS for CMIP6, currently available for 1750-2015
• Volcanic emission is based on the TOMS- and OMI-based estimates, currently available for 1979-2018 (the eruptive (1979- Feb 2019) and degassing (2000-2005) volcanic SO2 emissions from S. Carn in an excel sheet can be found here carn_volcemi_erup_degassing_as-of-feb2019.xls.

A brief description, recommendations of anthropogenic emission beyond 2014 and biomass burning emissions beyond 2015, additional biomass burning data set, access to the emission data sets, and other information can be found here a3_anthro-bb-volc_emission_requirements_v2019-02-26.pdf.

To diagnose and evaluate the characteristics and model differences of transport and removal processes, it is important to implement common tracers of transport and dry/wet removal processes across all models.

• Transport tracer: CO with 50-day lifetime with prescribed direct anthropogenic and biomass burning emissions, oxidation from NMVOC from anthropogenic, biomass burning, and biogenic emissions, and oxidation from CH4.
• Removal tracer: Pb-210, which is formed from Rn-222 decay (5.5-day lifetime). Its dry/wet removal processes should be treated the same as sulfate.

Descriptions of tracers, access to the CO tracer sources and Rn-222 emission, and other information can be found here a3_tracer_requirements_v2019-10-10c.pdf.

The diagnostics for most of the experiments mentioned on this wiki page are put together here:

AeroCom experiments diagnostics sheets 28.2.2019

Be aware of updates ! versions will have a date attached.

As for earlier major AeroCom studies, the intention here is to assemble in spring 2019 a set of model simulations representing the state of the art of aerosol modeling. Most important diagnostics for analysing aerosol life cycles and forcing are requested. Simulations for years 2010 and 1850 shall form the basis for a reference paper on phase III of AeroCom and additional experiments and analysis (eg absorption, aircraft, in-situ comparison, historical, median model…). Diagnostics are coordinated with AerChemMIP, so modelling groups may choose to link to simulations made under CMIP6. Submission of data is expected to be done to the AeroCom database at MetNo.

Contact: Michael Schulz michael.schulz@met.no

Status: ACTIVE taking submissions, Diagnostics and new instructions (new filenames) are assembled in new tables, see below (Feb 2019).

Submission deadline: 01 June 2019 ( welcome earlier when submitting eg for other experiments !)

Timeline: Initial analysis of forcing, life cycle analysis, comparison to basic parameters such as AOD, deposition, concentrations, scattering and absoprtion until next AeroCom workshop in Sep 2019, Barcelona. Reference publication to be submitted by December 2019.

Column with diagnostic requests in excel sheet: AP3-CTRL

Document(s) with more info: Kept in Google sheets see above

Aerosol shortwave absorption affects precipitation and other atmospheric phenomena, through local heating, altering lapse rates and affecting cloud formation. Presently, however, absorption from BC, brown carbon (absorbing OC) and dust is very diversely quantified among AeroCom models. There is also no strong observational constraint on the total, global (or regional) aerosol absorption (see paper linked below). Further, BC - the most strongly absorbing anthropogenic aerosol species - has been shown to cause significant spread in predicted precipitation change under global warming between recent Earth System Models. In response, this AeroCom Phase III experiment aims to better quantify the sources of intermodel spread in (total and per-species) short wave aerosol absorption. We request only standard fields (abs550aer, od550aer etc.), but at three wavelengths (550nm, 440nm, 870nm), to allow for more rigorous comparisons to observations. We also request per-species monthly absorption, at the three wavelengths, for BC, BrC and dust separately. Building on this analysis, we aim to provide an updated, hopefully stronger constraint on global mean aerosol absorption.

Contact: Bjorn Samset b.h.samset@cicero.oslo.no; Maria Sand maria.sand@cicero.oslo.no

Status: Active. Taking submissions.

Submission deadline: 01. June 2019

Timeline: Initial analysis completed by AeroCom 2019. Paper to be submitted by December 2019 (IPCC deadline).

Column with diagnostic requests in excel sheet: ABS

Document(s) with more info: Aerosol Absorption: Progress Towards Global and Regional Constraints (Samset et al. 2018)

The Clouds and the Earth’s Radiant Energy System (CERES) project produces a long-term global climate data record (CDR) that can be used to detect decadal changes in the Earth’s radiation budget (ERB) from the surface to the top-of-atmosphere (TOA). The CERES Energy Balanced and Filled (EBAF) product includes monthly mean shortwave (SW), longwave (LW), and net TOA all-sky and clear-sky radiative fluxes over 1 degree latitude by 1 degree longitude regions. The EBAF SW and LW fluxes are adjusted within their uncertainties to be consistent with the heat storage in the Earth-atmosphere system. EBAF also provides a gap-free monthly mean clear-sky flux map by inferring clear-sky fluxes from both CERES and MODIS measurement. Additionally, EBAF product also includes MODIS-based monthly mean cloud properties (cloud amount, optical depth, effective pressure, and daytime optical depth).

Comparisons between AeroCom phase III experiments with CERES EBAF fluxes will focus on:

1) Clear-sky flux comparisons between model outputs and CERES EBAF. Clear-sky flux differences are closely linked to aerosol differences, land and snow/ice surface albedo differences. Thus the clear-sky flux comparisons can reveal deficiencies in aerosol simulations and the surface albedo. This evaluation also has a clear linkage to “Remote Sensing Evaluation”.

2) All-sky flux comparisons between model outputs and CERES EBAF. All-sky flux differences are mostly related to cloud property differences. SW and LW fluxes are sensitive to different cloud properties and their differences can provide insights in the cloud filed simulated by the models.

3) Decadal trends comparison between model output and CERES EBAF at different spatial scales. These flux trends can be linked with trends of aerosol optical depth, sea ice, and cloud properties to better constrain model simulation.

Contact: Wenying Su, wenying.su-1@nasa.gov

Status: Accepting model submission.

Submission deadline: July 2019

Timeline: TBD

Column with diagnostic requests in excel sheet: AP3-CTRL

Document(s) with more info: TBD

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).

Remote sensing groups have provided us with aggregated (1 by 1 degree) observations. Model data will be collocated with these observations to reduce as much as possible spatio-temporal sampling issues. The evaluation should allow us to study model error in the context of observational uncertainty (estimated from ground site comparisons and diversity among satellite datasets). Interpretation of results will be facilitated by the regular CTRL2016 experiment information on emissions, depositions etc.

Contact: Nick Schutgens (Vrije Universiteit, NL); n.a.j.schutgens@vu.nl

Status:

Submission deadline: Submissions still accepted but contact Nick first

Timeline: Two papers submitted by the end of 2019

Column with diagnostic requests in excel sheet: 3 hourly 2D and 3D aerosol fields (mostly AOT)

Document(s) with more info: aerocom3_ctrl2016_remsens_v2.pdf or by emailing Nick Schutgens.

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

Contact: Betsy Andrews (NOAA/ESRL/GMD), Betsy.Andrews@noaa.gov

Status: TBD

Submission deadline: TBD

Timeline: TBD

Follow project progress here: https://docs.google.com/document/d/1buqxPbJ7DhWrwBUgTGV8b47HWAzaeyTTeSzViq8Fo4M/edit?usp=sharing

Column with diagnostic requests in excel sheet: TBD

Document(s) with more info:

List of stations with in-situ measurements to be used in comparison project: insitu_station_inventory.xlsx

Modeller commitments (updated as commitments are made): https://docs.google.com/spreadsheets/d/1NL-l5WQ0kUFQkq8SPEvAq2fmtCzHIjFWnoTmKsthUhU/edit?usp=sharing

Tools to extract station data at station locations from model fields, output into station netcdf file: ncl: https://github.com/kaizhangpnl/sample_insitu kindly provided by Kai Zhang

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. We encourage radiative forcing simulations, but if difficult to achieve on a short time frame we are interested also to have the aerosol fields without forcing diagnostics. To perform radiative forcing calculation in the case of using SST fields, we encourage double radiation calls. This output should as a minimum be every 10th year until 1980, thereafter a minimum of every 5th year 1980-2015 (preference yearly).

Contact: Gunnar Myhre gunnar.myhre@cicero.oslo.no

Status: Diagnostics and new instructions (new filenames) are given in the new excel sheet. Taking submission.

Submission deadline: 01 June 2019

Timeline: Initial analysis of trends in aerosols distribution and radiative forcing ready by next AeroCom workshop in September 2019. Paper to be submitted by December 2019 (IPCC deadline).

Column with diagnostic requests in excel sheet: HIST

Document(s) with more info:Concentrations and radiative forcing of anthropogenic aerosols from 1750 to 2014 simulated with the Oslo CTM3 and CEDS emission inventory (Lund et al., 2018) https://www.geosci-model-dev.net/11/4909/2018/gmd-11-4909-2018-discussion.html

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

Contact: Paul Ginoux (GFDL) paul.ginoux@noaa.gov

Status: Actual participants (Jan 2019): CAM5 (U. Wyoming), GEOS-Chem (U. l'Aquilla), INCA (IPSL/LSCE), AM4 (NOAA-GFDL)

Submission deadline: June 2019

Timeline: Analysis: completion for Aerocom 2019; Paper: 1st draft for Aerocom 2019; Manuscript submission by December 2019

Column with diagnostic requests in excel sheet: Aerocom Phase III Control (AP3-CTRL)

Document(s) with more info: anthro_dust_aerocomiii.pdf

Dust source: NetCDF files

“EXPERIMENT NAMES”:

The Anthro-dust experiment consists to run one control experiment (CTRL2016) with standard configuration for 3 years from 2010 to 2012, and perturbed cases with satellite based inventory (MDB2-A; MDB2-Ba…MDB2-Bd; MDB2-C), which differentiates between natural and land use dust sources. To better constrain the threshold of wind erosion (Ut0) a sensitivity study is performed with Ut0 multiplied by 1 (MDB2-Ba), 0.5 (MDB2-Bb),1.5 (MDB2-Bc) and 1.25 (MDB2-Bd) for land use sources (foo_ant; the natural source is shutdown). Then both, natural and anthropogenic dust sources are activate using everywhere Ut0. But before performing the perturbed case, it is necessary to perform a simulation (MDB2-A) with provided natural sources (foo_nat). This experiment is used to determine the global constant of emission(C) such that the global annual dust emissions from the control (C0) and new inventory (Cnew) have the same value. The last experiment MDB2-C uses both sources (foo), Cnew and Ut0.

Simulation period: 3 years from 2010 to 2012

“CTRL2016” 1. Simulate with your own sources using your own C0 and Uto.

“MDB2-A“ 2. Simulate with MDB2 natural sources with Uto, then calculate global emission Cnew to have same global mean annual emission as in 1. Cnew=C0 * (global mean annual emis exp1)/(global mean annual emis exp2)

3. Simulate with MDB2 anthropogenic sources with Cnew and with: “MDB2-Ba” a) Uto “MDB2-Bb“ b) 0.5*Uto “MDB2-Bc” c) 1.5*Uto “MDB2-Bd” d) 1.25*Ut0

“MDB2-C” 4. Simulate with MDB2 natural and anthropogenic sources with Cnew and Uto

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. In addition, this multi-model experiment also tackles two areas that have not been examined before in AeroCom: the change of dust particle sizes during the long-range transport, and the dust optical depth at the thermal infrared (10 um) wavelength that is mostly sensitive to dust aerosols, which can be compare to the commonly used value at the mid-visible wavelength. Details about the proposed experiment are described here aerocom_dusa_proposal_20191204.pdf. The model output variables are listed here aerocom3_dusa_diagnostics_20191202.xlsx, and the file of tagged region domains is provided in the netcdf file (0.5 deg) here dusrc_tagmap.x720_y360.nc.

Contact: Dongchul Kim (NASA GSFC) dongchul.kim@nasa.gov

Status: TBD

Submission deadline: 30 June 2020

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. Satellite remote sensing observations have been applied to characterize the three-dimensional distributions of dust and estimate the dust deposition and loss frequency along the trans-Atlantic transit on a decadal time scale. It is imperative to integrate these new in situ and remote sensing datasets with long-term data from ground-based networks in the region to systematically assess model simulations of dust deposition and identify major deficiencies of dust models. Details about the proposed analysis are described here: tadd_aerocom_exp_final.pdf

Contact: Hongbin Yu (NASA GSFC) Hongbin.Yu@nasa.gov

Status: TBD

Submission deadline: 12-31-2019

Timeline: TBD

Column with diagnostic requests in Google Doc excel sheet: AeroCom diagnostics CTRL + X 2018/2019, see column “TADD”

Document(s) with more info: TBD

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. The proposed UTLS model experiments has the following objectives: (1) Compare and evaluate the model simulated aerosol and precursors in the UTLS regions in recent decades, (2) examine the pathways of aerosols in the UTLS region (e.g., roles of convective transport, chemistry, and direct injection), (3) Assess the contributions of anthropogenic and volcanic emissions to the decadal variations of UTLS aerosols. It will be coordinated with and benefited from other community projects, such as the IGAC/SPARC Atmospheric Composition and Asian Monsoon (ACAM), and the SPARC Stratospheric Sulfur and its Role in Climate (SSiRC). These objectives will be achieved by designed model experiments described here: a3_utls_2019-11-26.pdf

Contact: Mian Chin (NASA GSFC) mian.chin@nasa.gov

Status: Taking submissions to AeroCom server.

Submission deadline: 31-05-2020

Column with diagnostic requests in Google Doc excel sheet: AeroCom diagnostics CTRL + X 2018/2019, see column “UTLS”

Document(s) with more info: TBD

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. In Part 1 of ACAM as stated in this docoment, we will only focus on aerosols simulated by global models. In Part 2, we may focus on trace gases by global models, and in Part 3 aerosols and trace gases by regional models.

Objectives: (1) Compare and evaluate model-simulated aerosol and related species in the Asian monsoon region with observations from remote sensing and recent ground-based and aircraft measurements; (2) Identify and examine pathways of trace gases and aerosols in the UTLS above the Asian monsoon with respect to the monsoon anticyclone, large-scale transport, and atmospheric chemistry; (3) Investigate interactions between Asian pollution and monsoon meteorology

A more detailed description can be find here acam_experiment_description_v10.pdf.

Contact: Xiaohua Pan xiaohua.pan@nasa.gov, Jonathon Wright jswright@tsinghua.edu.cn, Mian Chin mian.chin@nasa.gov

Last update: May 13, 2020 (Make sure to check the latest experiment description above)

Status: accepting model submissions

Submission deadline: July 31, 2020

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? This proposed ACRI study is to answer the above questions through a set of GCM model experiments described here: a3_acri_2019-01-21.pdf

Contact: Mian Chin (NASA GSFC) mian.chin@nasa.gov

Status: TBD

Submission deadline: 12-31-2019

Timeline: TBD

Column with diagnostic requests in Googld Doc excel sheet: AeroCom diagnostics CTRL + X 2018/2019, see column “ACRI”

Document(s) with more info: TBD

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.

Recent dedicated aircraft measurement campaigns and data collection efforts have delivered a large amount of in-situ aerosol measurements of great value to AeroCom modellers. The Global Aerosol Synthesis and Science Project (GASSP) dataset brings 1000s of separate aircraft measurement flights across 10s of campaigns into a single consistent database. Combining this with data from recent campaigns such as CLARIFY, ORACLES, AToM and ACE-ENA provides a unique opportunity to evaluate AeroCom model aerosol distributions across a wide range of regions and meteorological conditions.

Each campaign includes different measurements of aerosol properties such as size distributions and speciation, and each focuses on different regions or phenomena; however, they all provide valuable model constraints and all require similar sampling considerations. Some campaign or region focussed analyses build on the baseline experiment with their own sensitivity experiments or specialist diagnostics, such as the ATom experiment. Please refer to each extension analysis for further details.

For this experiment the flight track points will be provided in a single CF-conformant NetCDF format with time, latitude, longitude, altitude and pressure coordinates. A post-processing script can also be provided allowing interpolation from high-temporal resolution output (at least 3 hourly) using the CIS tool to output in the same CF-compliant NetCDF format as the sample data, and then deletion of the full output fields. Vertical interpolation will automatically be performed by height or pressure as required. Some models have implemented a ‘flight-track simulator’ to allow on-line interpolation of these spatially sparse measurement points, thus avoiding significant output storage requirements.

The CIS commands required are very simple and the syntax is described in the documentation documentation. An example command to extract the tracers from a set of model outputs for March 2009 would be:

cis col <tracer_vars>:model_file_2009_03_??.nc all_points_200903??.nc -o tracers_200903.nc

A python interface is also available if preferred.

Contact: Duncan Watson-Parris (Oxford) duncan.watson-parris@physics.ox.ac.uk, Philip Stier (Oxford) philip.stier@physics.ox.ac.uk

Status: Submission phase

Submission deadline: Summer 2020

Timeline: First publications ready Autumn 2020

Column with diagnostic requests in excel sheet: Aircraft

Document(s) with more info:

Experiment description: aerocom_aircraft_experiment_v1.7.docx

Requested diagnostics: See Phase III CTRL-X diagnostics ('atFlightTrack' sheet)

Flight-track points: All hindcast points (v1.1) All points fixed to 1850 (v1.1) All points fixed to 2008 (v1.1)

Ongoing analyses: Google Doc

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. We will reveal any new scientific findings and discuss current potential problems in AeroCom model simulations constrained by ATom measurements from process levels.

Contact: Huisheng Bian (NASA) huisheng.bian@nasa.gov; Christina Williamson (NOAA) christina.williamson@noaa.gov; Mian Chin (NASA) mian.chin@nasa.gov

Submission deadline: July 31, 2019

Status: accepting model submissions. Last update: Mar. 6, 2019.

Document(s) with more info:

Experiment description: atom_aerocom_plan_v3.docx

ATom 1-4 flighttracks: atom1-4-flighttracks.nc.tar

Diagnostic requests: See Phase III CTRL-X diagnostics (sheets of 'aermonthly-2d', 'aermonthly-3d', and 'atFlightTrack')

Abstract: 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. Degassing volcanos emitting large amount of sulphur dioxide forming large-scale aerosol plumes create ideal experimental conditions for constraining models (Malavelle et al., 2017, Nature, M17; Yuan et al., 2011, ACP, Y11). Aerosol plumes from degassing volcanos at Holuhraun in Iceland and Kilauea in Hawaii cover huge areas in North Atlantic and Tropical Pacific, respectively. Volcanic aerosols at these two locations affected low clouds in different environments and provide set-ups for investigating ACI for cold maritime stratiform and tropical trade cumulus clouds, respectively.

This experiment proposes to extend the protocol described in M17 to investigate ACI involving a larger group of ESMs. The experiment requests standard model outputs and should require no further model development. Diagnostic are organised in three packages, with the first mandatory package designed for characterising the big picture ACI (Monthly mean 3D and 2D fields). The two other packages are optional and piggy back on the AeroCom Indirect experiment to derive ACI metrics and cloud microphysics processes tendencies for warm clouds (3 hourly, mostly 2D fields). Analysis of the Holuhraun simulations will be coordinated by the University of Exeter (F. Malavelle). Analysis of the Kilauea simulations will be coordinated by NASA (T. Yuan).

Observations from different satellite sensors such as MODIS, CloudSat PR, CALIOP and CERES will be made available for model comparison at the big picture ACI level.

Contact: Florent Malavelle F.Malavelle@exeter.ac.uk (Holuhraun), Tianle Yuan tianle.yuan@nasa.gov (Kilauea)

Status: Ongoing

Submission deadline: accepting model submissions. Last update: May. 21, 2019.

Timeline: For Holuhraun: Model submissions started. Early analysis and presentation of results expected by Oct 2019. For Kilauea: Limited submission so far (4 groups have run the experiment with different emissions, we will coordinate and present early analyses at the Oct 2019 AEROCOM meeting.

Column with diagnostic requests in excel sheet: Column 'VolcACI' in aermonthy-2D, aermonthy-3D, aerfixed, aer6hr, aer3hr-2d and aer3hr-3D sheets. External link to the former diagnostics list for this experiment . Details for Kilauea updated.

Document(s) with more info: .docx.pdf.

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. Applying trajectory calculations to the meteorological fields from reanalysis and GCM data for the same location and time-period facilitates a highly transparent means for evaluating the discrepancies between models and observations as a function of aerosol source/sink pathways during transport to a measurement station. This analysis technique will have wide scientific relevance as it facilitates tracing the aerosol evolution during transport to investigate the role of sources, dynamical processes and sinks on the aerosol properties in the model. For further details, see experiment documentation linked below.

Ongoing analysis: A report summarising the results from the development phase of the experiment can be found here.

Contact: Daniel Partridge (D.G.Partridge@exeter.ac.uk), Paul Kim (p.s.kim@exeter.ac.uk)

Status: ongoing.

Submission deadline: accepting model submissions.

Timeline: obtain results for initial (phase 1) submissions by May 2019. Presentation of results at Oct 2019 AeroCom meeting.

Column with diagnostic requests in excel sheet: TRAJ

Experiment description: The experiment rationale and description can be found here.

Document(s) with more info: All relevant documentation (including the files linked above) can be found here.

Last update: Jul. 20th, 2020

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. Sophisticated earth system models typically treat aerosols cloud interactions as a series of processes starting with aerosols and total Cloud Condensation Nuclei (CCN), to activation of aerosols as cloud droplets (Activation) to the loss process for cloud water, often through precipitation (Autoconversion). This experiment will test several different processes to see how ACI are sensitive to the process representations, and in what combination.

Each participating model will run a 3-parameter perturbed parameter experiment (PPE). This will consist of 39 pre-defined simulations that will be run for the years 2008 and 1850 + any required spin-up time. The 2008 simulations will be the priority but 1850 simulations are required to calculate the radiative forcing. This is a total of 78 years of simulation + spin-up. The pre-defined simulations will allow statistical modelling to be carried out for defined diagnostics producing sensitivity analyses that will be used to compare individual models following Lee, et al. 2011 and Carslaw et al. 2013. Participants are also requested to submit the results of the one-at-a-time high/low tests used to test the implementation of the perturbation for initial comparisons.

Contact: Lindsay Lee L.A.Lee@leeds.ac.uk

Status: Sign-up open and one-at-a-time test results being accepted. PPE simulation results accepted from September 2019.

Submission deadline: For inclusion in AeroCom 2019, one-at-a-time results should be received in August 2019. For inclusion in AeroCom 2020 monthly diagnostics should be submitted by July 2020.

Timeline: We hope to present some high/low comparisons from multiple models at AeroCom 2019. First results from the multi-model PPE will be presented at AeroCom 2020.

Column with diagnostic requests in excel sheet: TBD

Document(s) with more info: Cloud experiment protocol

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. at Aeronet stations), and over-predict concentrations in remote regions (e.g. as measured by HIPPO). By exploring the uncertainties in the dominant emission and removal processes, and in the key radiative property (the imaginary part of the refractive index) and comparing with a variety of observations we hope to better constrain the radiative forcing.

We aim to address the uncertainty in direct radiative forcing in a unique way by developing a new approach to tackle two dominant sources of model uncertainty: structural uncertainty and parametric uncertainty. We will do this via a multi-model perturbed parameter ensemble (MMPPE).

Each participating model will run a 3-parameter perturbed parameter ensemble (PPE). This will consist of 39 pre-defined simulations that will be run for the years 2008 and 1850 + any required spin-up time. The 2008 simulations will be the priority but 1850 simulations are required to calculate the radiative forcing. This is a total of 78 years of simulation + spin-up. The pre-defined simulations will allow statistical modelling to be carried out for defined diagnostics producing sensitivity analyses that will be used to compare individual models following Lee, et al. 2011 and Carslaw et al. 2013. Participants are also requested to submit the results of the one-at-a-time high/low tests used to test the implementation of the perturbation for initial comparisons.

Contact: Lindsay Lee L.A.Lee@leeds.ac.uk

Status: Sign-up open and one-at-a-time test results being accepted. PPE simulation results accepted from September 2019.

Submission deadline: For inclusion in AeroCom 2019, one-at-a-time results should be received in August 2019. For inclusion in AeroCom 2020 monthly diagnostics should be submitted by July 2020.

Timeline: We hope to present some high/low comparisons from multiple models at AeroCom 2019. First results from the multi-model PPE will be presented at AeroCom 2020.

Column with diagnostic requests in excel sheet: TBD

Document(s) with more info: BC experiment protocol

External Link

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. However, most atmospheric chemistry transport models (CTMs) assume that fire emissions are dispersed only within PBL, or use simple plume-rise parameterizations.The objectives of this project is to test the sensitivity of various model results to biomass burning smoke injection height, where the biomass burning injection height is based on MISR (Val Martin et al., 2010; 2018), as compared to the nominal model value.This proposed BBEIH study is to answer this question through a set of GCM model experiments. Please read the details in the document: aerocom_phase_iii_plume_injection_height_v16.pdf

Phase III Organizers: Xiaohua Pan, Ralph Kahn, Mian Chin, Maria Val Martin

Contact: Xiaohua Pan xiaohua.pan@nasa.gov, Ralph Kahn ralph.kahn@nasa.gov

Last update: May. 13, 2020

Status: accepting model submissions

Submission deadline: June 30, 2020

Column with diagnostic requests in Googld Doc excel sheet: AeroCom diagnostics CTRL + X 2018/2019, see column “BBEIH”

A short description (about a paragraph) should go here. A detailed description can be found here: aerocompiii_insitu_pnsd_description_v1.pdf

Contact: Markus Fiebig (NILU), Markus.Fiebig@nilu.no; Stephen Platt (NILU), StephenMatthew.Platt@nilu.no

Status: TBD

Submission deadline: TBD

Timeline: TBD

Column with diagnostic requests in excel sheet: TBD

Document(s) with more info:

List of stations with in-situ measurements to be used in comparison project 20160310_insitu_pnsd_station_list.xlsx

Tools to extract station data at station locations from model fields, output into station netcdf file: ncl: https://github.com/kaizhangpnl/sample_insitu kindly provided by Kai Zhang

Contact: Michael Schulz (MetNo), michael.schulz@met.no

Experiment Description and motivation:

The model versions used for the different experiments are often not easily comparable. New model versions should be documented regularly to establish a state of the art comparison yearly. For this purpose AeroCom offers a semi-automatic platform with visualization via the AeroCom webinterface. Evaluation with surface observations and Aeronet observations will complete the documentation of emissions, removal, burden, lifetime of the major aerosol species.

In 2016 additional motivation we try to revisit the AeroCom evaluation done in 2006. Also - several experiments have been launched (in-situ optical properties, size, biomass burning, dust, nitrate and detailed 3h hourly evaluation to remote sensing data) which should be linked through common output. Also - models prepare for CMIP6 and might be interested in quick feedback.

Deadline

Deadline for model submissions to be analysed before the Beijing AeroCom workshop: 1.September, on the condition that formatting and naming of files follows the instructions below.

Experiment name: AP3-CTRL2016-PD and AP3-CTRL2016-PI

Two experiments:
One with current eg HTAPv2 emissions (*-PD)
One with preindustrial emissions (*-PI)
OR better using the new CMIP6 emissions….

Output request

Output requested (2D fields, Monthly averages, preferably model nudged to year 2010 meteorology):

Variables-Parameter:Speciation
EMI-Emissions: BC, OA, SO2, DMS, NOx, VOC, DUST, SS
(column integrated, if emission at altitude, eg SOA is accumulated in OA emissions)
LOAD-Column Loads: BC, OA, SO4, NO3, DUST, SS
SCONC-Surface concentrations: PM10, PM25, BC, OA, SO4, NO3, DUST, SS
DEP-Total Deposition: BC, OA, SO4, NO3, DUST, SS
OD550-Aerosol optical depth @550nm: AER, fine mode AER, coarse mode AOD, (tier 2: BC, OA, SO4, NO3, DUST, SS)
Total AOD effective in radiative forcing code (OD550AER) and clearsky AOD (od550csaer)

SWTOA-Top of Atm Fluxes clear-sky and all-sky :

  AER, fine mode AER, coarse mode (//tier 2:// AOD, BC, OA, SO4, NO3, DUST, SS) \\  

LWTOA-Fluxes clear-sky and all-sky : AER, fine mode AER, coarse mode
CCN Number concentration @ 850 hPa
IN Number concentration @ 100 hPa
Total Cloud cover
Cloud Water Path
Low level cloud cover
Precipitation rate

One file per variable and year. Variable names: emioa, emibc, …depbc…swtoacsaer, swtoaasaer…

Use latest variable names from AerChemMIP, and units, standard names as given in these tables:

AerChemMIP tables in EXCEL: EXCEL tables of AerChemMIP data request

OFFICIAL DATA REQUEST THROUGH CMIP6: CMIP6 data request

The directory /media/scratch/incoming/AEROCOM-P3-AUTO-UPLOAD allows for automatic incorporation into the AeroCom database and workup. Uploaded files are processed automatically by the AeroCom tools and transferred into the AeroCom phase III data directory. (Still in testphase, please send an email also to michael.schulz@met.no and anna.benedictow@met.no)

If correct in format and with correct filenames, results uploaded here will be processed over night and appear after few days as image catalogue on http://aerocom.met.no/cgi-bin/aerocom/surfobs_annualrs.pl?PROJECT=AEROCOM&MODELLIST=AEROCOM-Phase-III

Short Recipe (Long version: https://wiki.met.no/aerocom/data_submission)

1) Name files according to HTAPII/AeroComPhaseIII standards. One file per year and variable
aerocom3_<ModelName>_<ExperimentName>_<VariableName>_<VerticalCoordinateType>_<Period>_<Frequency>.nc
for example
aerocom3_GOCART_AP3-CTRL2016_od550aer_Column_2010_monthly.nc

2) Check for cf compliance some files (http://cf-checker.met.no/upload)

3a) obtain account on aerocom-users server

3) create directory on aerocom-users.met.no server:
/media/scratch/incoming/AEROCOM_AUTO_UPLOAD/{MODELNAME}/renamed/
Use exactly the same model name as used for file names. Attention to lower&upper case!!

4) Put files directly into this “renamed” directory.
And send e-mail to jan.griesfeller and michael.schulz and anna.benedictow @met.no

Contact: Michael Schulz (MetNo), michael.schulz@met.no

Experiment Description and motivation:

The model versions used for the different experiments are often not easily comparable. New model versions should be documented regularly to establish a state of the art comparison yearly. For this purpose AeroCom offers a semi-automatic platform with visualization via the AeroCom webinterface. Evaluation with surface observations and Aeronet observations will complete the documentation of emissions, removal, burden, lifetime of the major aerosol species.

Deadline for model submissions to be anlaysed before the Frascati AeroCom workshop: 15.September, on the condition that formatting and naming of files follows the instructions below.

Experiment name: AP3-CTRL2015

Output requested (2D fields, Monthly averages, preferably year 2010 meteorology):
EMI Emissions: BC, OA, SO2, DMS, NOx, VOC, DUST, SS
LOAD Column Loads: BC, OA, SO4, NO3, DUST, SS
SCONC Surface concentrations: BC, OA, SO4, NO3, DUST, SS
DEP Total Deposition: BC, OA, SO4, NO3, DUST, SS
OD550 Aerosol optical depth @550nm: AER, OA, SO4, NO3, DUST, SS

The directory /media/scratch/incoming/AEROCOM-P3-AUTO-UPLOAD allows for automatic incorporation into the AeroCom database and workup. Uploaded files are processed automatically by the AeroCom tools and transfered into the AeroCom phase III data directory.

If correct in format and with correct filenames, results uploaded here will be processed over night and appear after few days as image catalogue on http://aerocom.met.no/cgi-bin/aerocom/surfobs_annualrs.pl?PROJECT=AEROCOM&MODELLIST=AEROCOM-Phase-III

Short Recipe (Long version: https://wiki.met.no/aerocom/data_submission)

1) Name files according to HTAPII/AeroComPhaseIII standards. One file per year and variable
aerocom3_<ModelName>_<ExperimentName>_<VariableName>_<VerticalCoordinateType>_<Period>_<Frequency>.nc
for example
aerocom3_GOCART_AP3-CTRL2015_od550aer_Column_2010_monthly.nc

2) Check for cf compliance some files (http://aerocom-test.met.no/upload)

3a) obtain account on aerocom-users server
3) create directory on aerocom-users server:
/media/scratch/incoming/AEROCOM_AUTO_UPLOAD/{MODELNAME}/renamed/
Use exactly the same model name as used for file names. Attention to lower&upper case!!

4) Put files directly into this “renamed” directory.

Contact: Huisheng Bian (GSFC/NASA, JCET/UMBC), Huisheng.Bian@nasa.gov

Experiment Description File

NH3 Emissions from Geia file

File name convention Nitrate Filename Protocol File

Essential nitrate variables file

Model output Specifications

BB experiment aims to compare the performance of the global models in simulating transport and optical properties of biomass burning emissions. We provide a set of about 400 fire&smoke cases observed by MODIS instrument (mostly on Terra satellite) in 2008, and compare model-simulated AOD to those observed by MODIS, as well as intercompare model properties. Given that all models are using the same BB emission input (GFEDv3 inventory) any differences in the output will indicate the differences between model configuration. Patterns in the model-model and model-satellite differences reveal nuances in either emission inventory or model setup that produce these differences. We expect to have some constructive feedback for both inventory developers and model groups regarding modeling the BB emissions. A detailed description can be found here (updated November 26, 2014): File

Contact: Mariya Petrenko (NASA GSFC/University of Maryland, USA), mariya.m.petrenko@nasa.gov, Ralph Kahn (NASA) Ralph.kahn@nasa.gov, Mian Chin (NASA) mian.chin@nasa.gov

Status: Model experiment finished, manuscript is in progress (Petrenko et al.)

Model Descriptions (Questionnaires filled by the groups in 2015): CAM5 (Kai Zhang, Hailong Wang, Xiaohong Liu): cam5_liu.xlsx cam5_references_foraerocomquestionnaie_liu.docx CIFS (Johannes Kaiser, Samuel Remy): aerocom_bb_models_questionnaire_cifs.xlsx cifs_figures_forquestionnaire.pdf cifs_references_foraerocomquestionnaire.docx ECHAM6-SALSA (Tero Mielonen, Tommi Bergman):aerocom_bb_models_questionnaire_echam6-salsa.xlsx GEOS-CHEM (Gabriele Curci, Anna Protonotariou): aerocom_bb_models_questionnaire_geos-chem.xlsx GOCART (Mian Chin, Mariya Petrenko): aerocom_bb_models_questionnaire_gocart.xlsx HadGEM3 (Ben Johnson): aerocom_bb_models_questionnaire_johnson_hadgem3-2.xlsx OsloCTM2 (Ragnhild Bieltvedt Skeie, Gunnar Myhre) aerocom_bb_models_questionnaire_1_osloctm2_final.xlsx SPRINTARS (Toshihiko Takemura): aerocom_bb_models_questionnaire_1_sprintars.xlsx sprintars_references_foraerocomquestionnaie.docx GISS ModelE (Keren Mezuman, Susanne Bauer, Kostas Tsigaridis): aerocom_bb_models_questionnaire_gissmodele.xlsx

The Unite Nations’ Task Force on Hemispheric Transport of Air Pollution (TF HTAP) is an international scientific cooperative effort to improve the understanding of the intercontinental transport of air pollution across the Northern Hemisphere. TF HTAP was organized in 2005 under the auspices of the UNECE Convention on Long-range Transboundary Air Pollution (LRTAP Convention). The model experiments for HTAP phase 2 have the following objectives: (1) Examine the transport of aerosols, including anthropogenic, dust, and biomass burning, from source regions to downwind regions, (2) assess the emission and transport impacts on regional and global air quality, ecosystems, public health, and climate, and (3) provide information on potential emission mitigation options A detailed description can be found here: File

Contact: Mian Chin (NASA) mian.chin@nasa.gov; Michael Schulz (MetNo) michael.schulz@met.no

Status: Model experiments finished, manuscript will be started soon (Chin et al.)

HTAP2 experiment description HTAP website