Project

4292

Chief Investigator

ALEXANDER, Dr Simon - Australian Antarctic Division

Title

The Antarctic Clouds and Radiation Experiment (ACRE)

Project aims

Clouds and their radiative effects have very large uncertainties in present climate models and their quantification continues to be a challenge. The inadequate representation of clouds and moist convection in climate models is the main limitation in current representations of the climate system. Large biases in shortwave radiation and sea surface temperatures in the Southern Ocean are characteristic of most models. These biases are due to an incorrect microphysical representation of clouds in models, in particular the ability to simulate sufficient low-level clouds. We will deploy a suite of instruments to Macquarie Island and then to Davis to characterise clouds and their effects on surface energy balance in the high southern latitudes. We will use the data collected to validate satellite cloud retrievals; evaluate weather forecasting and climate models; and aid in model development.

Project gallery


Project Summary of the Season 2015/16

The first year of ACRE was characterised by the installation of instruments and commencement of data collection. Since the project's approval, major successes have included:

(1) Approval from the US Department of Energy (DoE) Atmospheric Radiation Measurements program (ARM) for the MICRE (Macquarie Island clouds and radiation experiment) project, which is part of the ACRE deployment to Macquarie Island in April 2016.

(2) Application to and approval by ARM for a second, much larger and ambitious deployment of part of one of their mobile facilities onboard Aurora Australis during summer 2017/18 (project MARCUS) as part of ACRE. This will tie in with a large, international project SOCRATES during January 2018 (funding from NSF to be confirmed)

(3) Successful install and operation of AAD's polarisation lidar, the Bureau of Meteorology's cloud radar, University of Canterbury's ceilometer, CSIRO's aerosol CPC and CCNC instruments and the ARM surface radiation instruments (MICRE campaign) during the autumn 2016 resupply.

(4) Successful install and data collection for V1 - V3 during summer 2015/16 aboard Aurora Australis of the AAD's radiometers and all sky camera and University of Canterbury's ceilometer.

(5) Successful install and data collection by French scientists at Dumont d'Urville (for summer 2015/16) of the AAD's radiometers as part of their precipitation project.

Project Summary of the Season 2016/17

Surface-based remote sensing cloud, radiation and aerosol data have been collected on Macquarie Island since March 2016 in order to quantify seasonal and diurnal properties. Instruments have been provided for this purpose by the AAD, the Australian Bureau of Meteorology, the US Department of Energy's ARM program, CSIRO and the University of Canterbury (New Zealand).

Data collection continued during FY2016-17 at Macquarie Island although was interrupted by a laser failure in the AAD's POLAR lidar system. The lidar was returned to the factory in Novemember 2016 and resumed operation on Macquarie Island in March 2017. Additional ARM-MICRE instruments (two 2-channel microwave radiometers MWRs) were sent in to replace the non-working 3-Channel MWR over summer. An ice nucleating particle detector was also deployed adjacent to the Clean Air Laboratory in March 2017. The Bureau of Meteorology's cloud radar was removed in March 2017 as scheduled. The CSIRO aerosol instruments and the University of Canterbury's ceilometer operated well for the first year of operation and remain on the island.

Project Summary of the Season 2017/18

The 2017/18 summer observational season was extraordinarily successful. The deployment of the US Department of Energy's Atmospheric Radiation Measurement (ARM) program instruments aboard the Aurora Australis for the entire summer has resulted in a unique and valuable dataset. The clouds, aerosols and precipitation data collected during multiple transects of the Southern Ocean, and especially the data collected at high latitudes (south of 60S) will provide a plethora of new science results over coming years. Already, scientists and students from multiple institutions have commenced work using the ARM data.

The second and final year of cloud, aerosol and precipitation observations were completed at Macquarie Island. The relatively small set of instruments deployed performed as well as could be expected in this most challenging of environments. The instruments were returned to Australia in March 2018 as scheduled.

Two externally-led projects were also part of the ACRE PI's summer of Southern Ocean science observations. Firstly, a US NSF-funded research aircraft flew out of Hobart to make 16 flights of in-situ cloud and aerosol observations over the Southern Ocean. Secondly, RV Investigator carried a smaller suite of clouds and aerosol instruments to that aboard Aurora Australis, but timed and located to allow overflights by the research aircraft to co-ordinate surface-based and in-situ observations.

Project Summary of the Season 2018/19

We deployed our clouds and radiation instruments to Davis station, Antarctica during summer 2018/19 for the purpose of studying the unique properties of the pristine clouds found at these high latitudes. Although preliminary analyses have only just commenced, we already have identified examples of multiple layers of thin super-cooled liquid water clouds (i.e. liquid water clouds existing at temperatures below zero), which often have ice falling out of them.

During the last twelve months, we have advanced our understanding of Southern Ocean cloud, radiation and aerosol processes. We have completed a detailed study quantifying the relationship between cloud and surface radiation fields measured onboard Aurora Australis; and determined the vertical and latitudinal structure of sea-salt aerosols which assist in cloud formation. We are also advancing several studies using data from the MARCUS field campaign (aboard Aurora Australis during summer 2017/18), ranging from understanding the occurrence of super-cooled liquid water cloud to quantifying ice nucleating particles.

Final Summary of Project Achievements

The Antarctic Clouds and Radiation Experiment (ACRE) was led by the AAD and brought together national and international research scientists in order to understand and quantify key cloud microphysical properties over the high Southern latitudes. The experimental component centred on three campaigns which were designed to ensure that a wide variety of latitudes were sampled, and the seasonal cycle captured at fixed ground-based locations.

Some of the ACRE science highlights include:
(a) Common occurrence of supercooled clouds and drizzle in high-latitude cloud systems
(b) Active generating cells are present within cyclones south of the Polar Front
(c) Persistent dried sea-salt layer is present above the surface well-mixed boundary layer in the mid-latitude Southern Ocean, but absent further south
(d) Clouds near the Antarctic coast exist at times in regions of higher aerosol loading, which suggests sensitivity of cloud properties to biogenic aerosols
(e) The amount of ice nucleating particles (INP) over the Southern Ocean are around 1000 times lower than previously believed
(f) Incorporating the correct amount of INP into high-resolution WRF simulations at Mawson enables supercooled liquid water clouds to be produced, in accordance with observations
(g) Quantification of Southern Ocean shortwave radiation biases using the HadGEM3 global climate model and MERRA reanalysis
(h) Quantification of the underestimate of low-level boundary clouds by satellite, when compared with surface-based observations

We supported two US Department of Energy Atmospheric Radiation Measurement (ARM) campaigns through ACRE, specifically a two-year deployment on Macquarie Island (2016 - 2018), which supplemented AAD, BoM and CSIRO instrumentation; and the deployment of an ARM Mobile Facility aboard Aurora Australis for summer 2017 - 2018, which provided a unique clouds, aerosol and radiation dataset at high southern oceanic latitudes and over sea ice. These data are all freely accessible to the international community.

We note that these datasets produced continue to be analysed by research groups in Australia and overseas. In particular, through the Australian Antarctic Programme Partnership, work continues using these ACRE datasets (along with others collected in the Southern Ocean) for ACCESS model evaluation and improvement.

Category 1: Peer-reviewed literature

Klekociuk A.R., Ottaway D.J., MacKinnon A.D., Reid I.M., Twigger L.V., Alexander S.P. (2020) Australian Lidar Measurements of Aerosol Layers Associated with the 2015 Calbuco Eruption, Atmosphere .; [Ref: 16235]

Alexander S.P., Protat A. (2020) Vertical profiling of aerosols with a combined Raman-elastic backscatter lidar in the remote Southern Ocean marine boundary layer 43 – 66°S 132 – 150°E, Journal of Geophysical Research 12107 – 12125; [Ref: 16349]

Vignon E., Picard G., Duràn-Alarcòn C., Alexander S.P., Gallée H., Berne A. (2020) Gravity wave excitation during the coastal transition of an extreme katabatic flow in Antarctica, Journal of the Atmospheric Sciences 1295 – 1312; [Ref: 16350]

Kuma P., McDonald A.J., Morgenstern O., Alexander S.P., Cassano J.J., Garrett S., Halla J., Hartery S., Williams J. (2020) Evaluation of Southern Ocean cloud in the HadGEM3 general circulation model and MERRA-2 reanalysis using ship-based observations, Atmospheric Chemistry and Physics 6607-6630; [Ref: 16351]

Wang H., Klekociuk A.R., French W.J.R., Alexander S.P., Warner T.A. (2020) Measurements of cloud radiative effect across the Southern Ocean 43°S–79°S 63°E–158°E, Atmosphere 1-22; [Ref: 16353]

Jumelet J., Klekociuk A.R., Alexander S.P., Bekki S., Hauchecorne A., Vernier J.P., Fromm M., Keckhut P. (2020) Detection of aerosols in Antarctica from long-range transport of the 2009 Australian wildfires, Journal of Geophysical Research .; [Ref: 16354]

Guyot A., Protat A., Alexander S.P., Klekociuk A.R. (2022) Detection of supercooled liquid water containing clouds with ceilometers: development and evaluation of deterministic and data-driven retrievals, Atmospheric Measurement Techniques .; [Ref: 16565]

Gehring J., Vignon E., Billault-Roux A.C., Ferrone A., Protat A., Alexander S.P. (2022) Orographic Flow Influence on Precipitation During an Atmospheric River Event at Davis, Antarctica, JGR Atmospheres .; [Ref: 16575]

McFarquhar G.M., Bretherton C.S., Marchand R., Alexander S., Klekociuk A.R. (2021) Observations of Clouds, Aerosols, Precipitation, and Surface Radiation over the Southern Ocean: An Overview of CAPRICORN, MARCUS, MICRE, and SOCRATES, Bulletin of the American Meteorological Society .; [Ref: 16618]

Fiddes S.L. (2022) Southern Ocean cloud and shortwave radiation biases in a nudged climate model simulation: does the model ever get it right?, Atmospheric Chemistry and Physics .; [Ref: 16626]

Moore K.A., Alexander S.P., Humphries R.S. (2022) Estimation of sea spray aerosol surface area over the Southern Ocean using scattering measurements, JGR Atmospheres .; [Ref: 16627]

Tansey E., Marchand R., Protat A., Alexander S.P., Ding. S. (2022) Southern Ocean Precipitation Characteristics Observed From CloudSat and Ground Instrumentation During the Macquarie Island Cloud & Radiation Experiment (MICRE): April 2016 to March 2017, Journal of Geophysical Research: Atmospheres .; [Ref: 16673]

Alexander S.P., Klekociuk A.R. (2021) Constraining Ice Water Content of Thin Antarctic Cirrus Clouds Using Ground-Based Lidar and Satellite Data, Journal of the Atmospheric Sciences .; [Ref: 16726]

Alexander S.P., McFarquhar G.M., Marchand R., Protat A., Vignon E., Mace G.G., Klekociuk A.R. (2021) Mixed-Phase Clouds and Precipitation in Southern Ocean Cyclones and Cloud Systems Observed Poleward of 64°S by Ship-Based Cloud Radar and Lidar, Journal of Geophysical Research: Atmospheres .; [Ref: 16727]

McCluskey C.S., Gettelman A., Bardeen C.G., DeMott P.J., Moore K.A., Alexander S.P. (2023) Simulating Southern Ocean Aerosol and Ice Nucleating Particles in the Community Earth System Model Version 2, Journal of Geophysical Research Atmospheres .; [Ref: 16765]

Humphries R.S., Keywood M.D., Ward J.P., Harnwell J., Alexander S.P., Klekociuk A.R., Hara K., McRobert I.M., Protat A. (2023) Measurement report: Understanding the seasonal cycle of Southern Ocean aerosols, Atmospheric Chemistry and Physics .; [Ref: 16768]

Mace. G.G., Protat A., Humphries R.S., Alexander S.P. (2020) Southern Ocean Cloud Properties Derived From CAPRICORN and MARCUS Data, Journal of Geophysical Research: Atmospheres .; [Ref: 16805]

Vignon E., Alexander S.P., DeMott P.J., Sotiropoulou G., Gerber F., Hill T.C.J., Marchand R., Nenes A., Berne A. (2021) Challenging and Improving the Simulation of Mid-Level Mixed-Phase Clouds Over the High-Latitude Southern Ocean, Journal of Geophysical Research: Atmospheres .; [Ref: 16818]

Raman A., Hill T., DeMott P.J., Singh B., Zhang K., Ma P-L. , Wu M., Wang H., Alexander S.P., Burrows S.M. (2023) Long-term variability in immersion-mode marine ice-nucleating particles from climate model simulations and observations, Atmospheric Chemistry and Physics .; [Ref: 16867]

Noh Y-J. , Miller S.D, Heidinger A.K., Mace G., Protat A., Alexander S.P. (2019) Satellite-based detection of daytime supercooled liquid-topped mixed-phase clouds over the Southern Ocean using the Advanced Himawari Imager, Journal of Geophysical Research 2677-2701; [Ref: 16109]

Sato K., Inoue J., Alexander S.P., McFarquhar G., Yamazaki Y. (2018) Improved reanalysis and prediction of atmospheric fields over the Southern Ocean using campaign-based radiosonde observations, Geophysical Research Letters 11406-11413; [Ref: 16110]

Huang Y., Franklin C.N., Siems S., Manton M., Chubb T., Lock A., Alexander S., Klekociuk A. (2015) Evaluation of boundary-layer cloud forecasts over the Southern Ocean in a limited-area numerical weather prediction system using in situ space-borne and ground-based observations, Quarterly Journal of the Royal Meteorological Society 141(691). 2259–2276; [Ref: 15887]

Bühl J., Alexander S.P., Crewell S., Heymsfield A., Kalesse H., Khain A., Maahn M., Van Tricht K., Wendisch M. (2017) Ice Formation and Evolution in Clouds and Precipitation: Measurement and Modeling Challenges: Chapter 10 Remote Sensing, Meteorological Monographs 58. 10.1-10.21; [Ref: 15890]

Alexander S.P., Orr A., Webster S., Murphy D.J. (2017) Observations and fine-scale model simulations of gravity waves over Davis, East Antarctica (69°S, 78°E), Journal of Geophysical Research 122(14). 7355–7370; [Ref: 15891]

Alexander S.P., Protat A. (2018) Cloud Properties Observed From the Surface and by Satellite at the Northern Edge of the Southern Ocean, Journal of Geophysical Research: Atmospheres 123. 14pp; [Ref: 15928]

Klekociuk A.R., French W.J.R., Alexander S.P., Kuma P., McDonald A.J. (2019) The state of the atmosphere in the 2016 southern Kerguelen Axis campaign region, Deep Sea Research Part II: Topical Studies in Oceanography .; [Ref: 16035]

Category 3: Conference paper

Alexander S.P., Protat A. (2019) Vertical profiling of clouds and aerosols across the Southern Ocean, CGU General Assembly 2019, Vienna, Austria, 7-12 April 2019 .; [Ref: 16116]

Alexander S. (2018) Southern Ocean clouds and aerosols measured from ships and Macquarie Island, Antarctic and Southern Ocean Forum, Hobart, Australia, 14-17 August 2018. .; [Ref: 16117]

Ding S., McFarquhar G., Alexander S.P. (2018) Statistical Distributions of Macrophysical Cloud and Aerosol Properties over the Southern Ocean during MARCUS: Impacts of Environmental Conditions, American Meteorological Society, Vancouver, Canada, July 2018 .; [Ref: 16118]

DeMott P.J., McCluskey C.S., Moore K.J., Levin E.J.T., Hill T.C.J., Twohy C.H., Toohey D., Stith J.L., McFarquhar G.M., Marchand R., Alexander S., Gettelman A., Protat A., Humphries R.S., Kreidenweis S.M. (2018) Spatial and temporal distributions of ice nucleating particles over the Southern Oceans, Advances Earth and Space Science, Fall Meeting Washington DC, Dec 2018. .; [Ref: 16119]

McFarquhar G.M., Bretherton C., Marchand R.T., DeMott P.J., Alexander S.P., Protat A., Roberts G., Twohy C.H., Toohey D.W., Siems S., Huang Y., Wood R., Rauber R.M., Lasher-Trapp S., Jensen J.B., Stith J.L., Mace J., Um J., Jaervinen M., Schnaiter M., Gettelman A., Sanchez K.J., McCluskey C.S., McCoy I.L., Moore K.A., Hill T.C.J., Rainwater B. (2018) New Unique Observations of Clouds, Aerosols and Precipitation over the Southern Ocean: An Overview of SOCRATES and MARCUS, American Meteorological Society, Vancouver, Canada, July 2018. .; [Ref: 16120]

Bretherton C.S., McFarquhar G.M., Marchand R., Protat A., Alexander S., Gettelman A., Ming Y. (2018) The Southern Ocean Climate Studies: Observations and modeling of Southern Ocean clouds and aerosols, Advances Earth and Space Science, Fall Meeting Washington DC, Dec 2018. .; [Ref: 16121]

Alexander S.P., Protat A., Marchand R.T., McFarquhar G.M., Nguyen H., McDonald A.J., Klekociuk A. (2018) Cloud Properties over the Southern Ocean Observed from the Surface, American Meteorological Society, Vancouver, Canada, July 2018. .; [Ref: 16122]

Category 3: Verbal presentation

Klekociuk A.R., Alexander S.P., Protat A. (2017) The Antarctic Clouds and Radiation Experiment and Cloud Properties at Extratropical Southern Latitudes, Australian Meteorological and Oceanographic Society Public Lecture, Adelaide Australia , 1 May 2017 .; [Ref: 16053]