Description: We present a Lagrangian convective transport scheme developed for global chemistry and transport models, which considers the variable residence time that an air parcel spends in convection. This is particularly important for accurately simulating the tropospheric chemistry of short-lived species, e.g., for determining the time available for heterogeneous chemical processes on the surface of cloud droplets. In current Lagrangian convective transport schemes air parcels are stochastically redistributed within a fixed time step according to estimated probabilities for convective entrainment as well as the altitude of detrainment. We introduce a new scheme that extends this approach by modeling the variable time that an air parcel spends in convection by estimating vertical updraft velocities. Vertical updraft velocities are obtained by combining convective mass fluxes from meteorological analysis data with a parameterization of convective area fraction profiles. We implement two different parameterizations: a parameterization using an observed constant convective area fraction profile and a parameterization that uses randomly drawn profiles to allow for variability. Our scheme is driven by convective mass fluxes and detrainment rates that originate from an external convective parameterization, which can be obtained from meteorological analysis data or from general circulation models. We study the effect of allowing for a variable time that an air parcel spends in convection by performing simulations in which our scheme is implemented into the trajectory module of the ATLAS chemistry and transport model and is driven by the ECMWF ERA-Interim reanalysis data. In particular, we show that the redistribution of air parcels in our scheme conserves the vertical mass distribution and that the scheme is able to reproduce the convective mass fluxes and detrainment rates of ERA-Interim. We further show that the estimated vertical updraft velocities of our scheme are able to reproduce wind profiler measurements performed in Darwin, Australia, for velocities larger than 0.6 m s−1. SO2 is used as an example to show that there is a significant effect on species mixing ratios when modeling the time spent in convective updrafts compared to a redistribution of air parcels in a fixed time step. Furthermore, we perform long-time global trajectory simulations of radon-222 and compare with aircraft measurements of radon activity.

Description: © The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Hagos, S., Foltz, G. R., Zhang, C., Thompson, E., Seo, H., Chen, S., Capotondi, A., Reed, K. A., DeMott, C., & Protat, A. Atmospheric convection and air-sea interactions over the tropical oceans: scientific progress, challenges, and opportunities. Bulletin of the American Meteorological Society, 101(3), (2020): E253-E258, doi:10.1175/BAMS-D-19-0261.1.

Description: Over the past 30 years, the scientific community has made considerable progress in understanding and predicting tropical convection and air–sea interactions, thanks to sustained investments in extensive in situ and remote sensing observations, targeted field experiments, advances in numerical modeling, and vastly improved computational resources and observing technologies. Those investments would not have been fruitful as isolated advancements without the collaborative effort of the atmospheric convection and air–sea interaction research communities. In this spirit, a U.S.- and International CLIVAR–sponsored workshop on “Atmospheric convection and air–sea interactions over the tropical oceans” was held in the spring of 2019 in Boulder, Colorado. The 90 participants were observational and modeling experts from the atmospheric convection and air–sea interactions communities with varying degrees of experience, from early-career researchers and students to senior scientists. The presentations and discussions covered processes over the broad range of spatiotemporal scales (Fig. 1).

Description: The workshop was sponsored by the United States and International CLIVAR. Funding was provided by the U.S. Department of Energy, Office of Naval Research, NOAA, NSF, and the World Climate Research Programme. We thank Mike Patterson, Jennie Zhu, and Jeff Becker from the U.S. CLIVAR Project Office for coordinating the workshop.

Description: This dataset contains the data from an automatic weather station located at Davis, Antarctica in January 2019.

Description: This dataset contains the radiosoundings at 00:00 or 12:00 at Davis Station in January 2019.

Description: This dataset contains radar and ground-based measurements of precipitation collected from 08 to 10 January 2019 at Davis station, Antarctica. It includes observations from an X-band dual-polarisation Doppler radar, a W-band Doppler cloud profiler, a VHF wind profiler, and a Raman Lidar. A classification of hydrometeor types based on dual-polarisation measurements is also available. The dual-frequency ratio based on the X-band and W-band reflectivity measurements is made available on a common grid. WRF simulations at 27, 9, 3, and 1 km resolution centred around Davis are provided. Finally, automatic weather station and radiosounding measurements are also included.

Description: This dataset describes a series of aerosol and meteorological measurements collected in the Great Barrier Reef (GBR) Marine Park collected during the "GBR as a significant source of climatically relevant aerosol particles" campaign, known as "Reef to Rainforest" (R2R). The data covers a broad area of the GBR marine park (-27.3091 to -16.95169 latitudinally, 145.9705 to 154.1146 longitudinally) over approximately one month, from 28th September, 2016 to 24th October, 2016. The data was collected at two sites – one aboard the Australian Government Research Vessel Investigator (RVI), and an onshore site at Garner's Beach, QLD, Australia (-17.8222S, 146.1023E). Parameters measured include particle size distribution, number concentration, composition cloud condensation nuclei (CCN) properties, concentrations of gases and markers including black carbon, radon, carbon monoxide, carbon dioxide, volatile organic compounds (VOCs), dimethylsulfide (DMS), upper air particle concentration/composition, cloud or low lying fog presence, cloud top height, depolarisation ratio, aerosol scattering and optical thickness. The observations were collected in the hope of improving our understanding of the local climate and aerosol properties, which in turn will improve local models and better inform regulatory bodies protecting the GBR.

Description: This dataset contains 3 minute resolution data with measurements from the SMPS (SMPS – TSI 3080 Classifier) and Condensation Particle Counters (CPC3787, CPC3782 and CPC3772). The SMPS gives the size distribution and the CPC gives the total particle number concentration. The number following the X is the midpoint diameter of the SMPS size bin, in nm. For instance, X11.3 denote the size bin with a diameter midpoint of 11.3 nm. As not all the CPCs were available to be used at all times, a linear model was used to model the total particle number concentration based off measurements from the three CPCs.

Description: 15 minute resolution data file with measurements from two Scanning Mobility Particle Sizers (SMPS) and one Aerodynamic Particle Sizer (APS). These instruments all measure the concentration of particles at a given size, increasing size incrementally to build a size distribution. The three size distributions are stitched together in a single distribution.

Description: Number concentrations for the 19 size classes measured by the LOAC. And Speciation index for the size classes. Species are classified into carbon, minerals, salts and water droplets. The upper and lower limit for each species varies between each size class. A speciation index chart is provided on a separate sheet (see "Additional metadata"). Numbers in the column heading represent the size bin range, as with the number concentration columns.