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Dan Lubin
,
Damao Zhang
,
Israel Silber
,
Ryan C. Scott
,
Petros Kalogeras
,
Alessandro Battaglia
,
David H. Bromwich
,
Maria Cadeddu
,
Edwin Eloranta
,
Ann Fridlind
,
Amanda Frossard
,
Keith M. Hines
,
Stefan Kneifel
,
W. Richard Leaitch
,
Wuyin Lin
,
Julien Nicolas
,
Heath Powers
,
Patricia K. Quinn
,
Penny Rowe
,
Lynn M. Russell
,
Sangeeta Sharma
,
Johannes Verlinde
, and
Andrew M. Vogelmann

Abstract

The U.S. Department of Energy Atmospheric Radiation Measurement (ARM) West Antarctic Radiation Experiment (AWARE) performed comprehensive meteorological and aerosol measurements and ground-based atmospheric remote sensing at two Antarctic stations using the most advanced instrumentation available. A suite of cloud research radars, lidars, spectral and broadband radiometers, aerosol chemical and microphysical sampling equipment, and meteorological instrumentation was deployed at McMurdo Station on Ross Island from December 2015 through December 2016. A smaller suite of radiometers and meteorological equipment, including radiosondes optimized for surface energy budget measurement, was deployed on the West Antarctic Ice Sheet between 4 December 2015 and 17 January 2016. AWARE provided Antarctic atmospheric data comparable to several well-instrumented high Arctic sites that have operated for many years and that reveal numerous contrasts with the Arctic in aerosol and cloud microphysical properties. These include persistent differences in liquid cloud occurrence, cloud height, and cloud thickness. Antarctic aerosol properties are also quite different from the Arctic in both seasonal cycle and composition, due to the continent’s isolation from lower latitudes by Southern Ocean storm tracks. Antarctic aerosol number and mass concentrations are not only non-negligible but perhaps play a more important role than previously recognized because of the higher sensitivities of clouds at the very low concentrations caused by the large-scale dynamical isolation. Antarctic aerosol chemical composition, particularly organic components, has implications for local cloud microphysics. The AWARE dataset, fully available online in the ARM Program data archive, offers numerous case studies for unique and rigorous evaluation of mixed-phase cloud parameterization in climate models.

Free access
Dan Lubin
,
Damao Zhang
,
Israel Silber
,
Ryan C. Scott
,
Petros Kalogeras
,
Alessandro Battaglia
,
David H. Bromwich
,
Maria Cadeddu
,
Edwin Eloranta
,
Ann Fridlind
,
Amanda Frossard
,
Keith M. Hines
,
Stefan Kneifel
,
W. Richard Leaitch
,
Wuyin Lin
,
Julien Nicolas
,
Heath Powers
,
Patricia K. Quinn
,
Penny Rowe
,
Lynn M. Russell
,
Sangeeta Sharma
,
Johannes Verlinde
, and
Andrew M. Vogelmann
Full access
Thomas Jung
,
Neil D. Gordon
,
Peter Bauer
,
David H. Bromwich
,
Matthieu Chevallier
,
Jonathan J. Day
,
Jackie Dawson
,
Francisco Doblas-Reyes
,
Christopher Fairall
,
Helge F. Goessling
,
Marika Holland
,
Jun Inoue
,
Trond Iversen
,
Stefanie Klebe
,
Peter Lemke
,
Martin Losch
,
Alexander Makshtas
,
Brian Mills
,
Pertti Nurmi
,
Donald Perovich
,
Philip Reid
,
Ian A. Renfrew
,
Gregory Smith
,
Gunilla Svensson
,
Mikhail Tolstykh
, and
Qinghua Yang

Abstract

The polar regions have been attracting more and more attention in recent years, fueled by the perceptible impacts of anthropogenic climate change. Polar climate change provides new opportunities, such as shorter shipping routes between Europe and East Asia, but also new risks such as the potential for industrial accidents or emergencies in ice-covered seas. Here, it is argued that environmental prediction systems for the polar regions are less developed than elsewhere. There are many reasons for this situation, including the polar regions being (historically) lower priority, with fewer in situ observations, and with numerous local physical processes that are less well represented by models. By contrasting the relative importance of different physical processes in polar and lower latitudes, the need for a dedicated polar prediction effort is illustrated. Research priorities are identified that will help to advance environmental polar prediction capabilities. Examples include an improvement of the polar observing system; the use of coupled atmosphere–sea ice–ocean models, even for short-term prediction; and insight into polar–lower-latitude linkages and their role for forecasting. Given the enormity of some of the challenges ahead, in a harsh and remote environment such as the polar regions, it is argued that rapid progress will only be possible with a coordinated international effort. More specifically, it is proposed to hold a Year of Polar Prediction (YOPP) from mid-2017 to mid-2019 in which the international research and operational forecasting communites will work together with stakeholders in a period of intensive observing, modeling, prediction, verification, user engagement, and educational activities.

Full access
William L. Smith Jr.
,
Christy Hansen
,
Anthony Bucholtz
,
Bruce E. Anderson
,
Matthew Beckley
,
Joseph G. Corbett
,
Richard I. Cullather
,
Keith M. Hines
,
Michelle Hofton
,
Seiji Kato
,
Dan Lubin
,
Richard H. Moore
,
Michal Segal Rosenhaimer
,
Jens Redemann
,
Sebastian Schmidt
,
Ryan Scott
,
Shi Song
,
John D. Barrick
,
J. Bryan Blair
,
David H. Bromwich
,
Colleen Brooks
,
Gao Chen
,
Helen Cornejo
,
Chelsea A. Corr
,
Seung-Hee Ham
,
A. Scott Kittelman
,
Scott Knappmiller
,
Samuel LeBlanc
,
Norman G. Loeb
,
Colin Miller
,
Louis Nguyen
,
Rabindra Palikonda
,
David Rabine
,
Elizabeth A. Reid
,
Jacqueline A. Richter-Menge
,
Peter Pilewskie
,
Yohei Shinozuka
,
Douglas Spangenberg
,
Paul Stackhouse
,
Patrick Taylor
,
K. Lee Thornhill
,
David van Gilst
, and
Edward Winstead

Abstract

The National Aeronautics and Space Administration (NASA)’s Arctic Radiation-IceBridge Sea and Ice Experiment (ARISE) acquired unique aircraft data on atmospheric radiation and sea ice properties during the critical late summer to autumn sea ice minimum and commencement of refreezing. The C-130 aircraft flew 15 missions over the Beaufort Sea between 4 and 24 September 2014. ARISE deployed a shortwave and longwave broadband radiometer (BBR) system from the Naval Research Laboratory; a Solar Spectral Flux Radiometer (SSFR) from the University of Colorado Boulder; the Spectrometer for Sky-Scanning, Sun-Tracking Atmospheric Research (4STAR) from the NASA Ames Research Center; cloud microprobes from the NASA Langley Research Center; and the Land, Vegetation and Ice Sensor (LVIS) laser altimeter system from the NASA Goddard Space Flight Center. These instruments sampled the radiant energy exchange between clouds and a variety of sea ice scenarios, including prior to and after refreezing began. The most critical and unique aspect of ARISE mission planning was to coordinate the flight tracks with NASA Cloud and the Earth’s Radiant Energy System (CERES) satellite sensor observations in such a way that satellite sensor angular dependence models and derived top-of-atmosphere fluxes could be validated against the aircraft data over large gridbox domains of order 100–200 km. This was accomplished over open ocean, over the marginal ice zone (MIZ), and over a region of heavy sea ice concentration, in cloudy and clear skies. ARISE data will be valuable to the community for providing better interpretation of satellite energy budget measurements in the Arctic and for process studies involving ice–cloud–atmosphere energy exchange during the sea ice transition period.

Full access
David H. Bromwich
,
Kirstin Werner
,
Barbara Casati
,
Jordan G. Powers
,
Irina V. Gorodetskaya
,
Francois Massonnet
,
Vito Vitale
,
Victoria J. Heinrich
,
Daniela Liggett
,
Stefanie Arndt
,
Boris Barja
,
Eric Bazile
,
Scott Carpentier
,
Jorge F. Carrasco
,
Taejin Choi
,
Yonghan Choi
,
Steven R. Colwell
,
Raul R. Cordero
,
Massimo Gervasi
,
Thomas Haiden
,
Naohiko Hirasawa
,
Jun Inoue
,
Thomas Jung
,
Heike Kalesse
,
Seong-Joong Kim
,
Matthew A. Lazzara
,
Kevin W. Manning
,
Kimberley Norris
,
Sang-Jong Park
,
Phillip Reid
,
Ignatius Rigor
,
Penny M. Rowe
,
Holger Schmithüsen
,
Patric Seifert
,
Qizhen Sun
,
Taneil Uttal
,
Mario Zannoni
, and
Xun Zou
Full access
David H. Bromwich
,
Kirstin Werner
,
Barbara Casati
,
Jordan G. Powers
,
Irina V. Gorodetskaya
,
François Massonnet
,
Vito Vitale
,
Victoria J. Heinrich
,
Daniela Liggett
,
Stefanie Arndt
,
Boris Barja
,
Eric Bazile
,
Scott Carpentier
,
Jorge F. Carrasco
,
Taejin Choi
,
Yonghan Choi
,
Steven R. Colwell
,
Raul R. Cordero
,
Massimo Gervasi
,
Thomas Haiden
,
Naohiko Hirasawa
,
Jun Inoue
,
Thomas Jung
,
Heike Kalesse
,
Seong-Joong Kim
,
Matthew A. Lazzara
,
Kevin W. Manning
,
Kimberley Norris
,
Sang-Jong Park
,
Phillip Reid
,
Ignatius Rigor
,
Penny M. Rowe
,
Holger Schmithüsen
,
Patric Seifert
,
Qizhen Sun
,
Taneil Uttal
,
Mario Zannoni
, and
Xun Zou

Abstract

The Year of Polar Prediction in the Southern Hemisphere (YOPP-SH) had a special observing period (SOP) that ran from 16 November 2018 to 15 February 2019, a period chosen to span the austral warm season months of greatest operational activity in the Antarctic. Some 2,200 additional radiosondes were launched during the 3-month SOP, roughly doubling the routine program, and the network of drifting buoys in the Southern Ocean was enhanced. An evaluation of global model forecasts during the SOP and using its data has confirmed that extratropical Southern Hemisphere forecast skill lags behind that in the Northern Hemisphere with the contrast being greatest between the southern and northern polar regions. Reflecting the application of the SOP data, early results from observing system experiments show that the additional radiosondes yield the greatest forecast improvement for deep cyclones near the Antarctic coast. The SOP data have been applied to provide insights on an atmospheric river event during the YOPP-SH SOP that presented a challenging forecast and that impacted southern South America and the Antarctic Peninsula. YOPP-SH data have also been applied in determinations that seasonal predictions by coupled atmosphere–ocean–sea ice models struggle to capture the spatial and temporal characteristics of the Antarctic sea ice minimum. Education, outreach, and communication activities have supported the YOPP-SH SOP efforts. Based on the success of this Antarctic summer YOPP-SH SOP, a winter YOPP-SH SOP is being organized to support explorations of Antarctic atmospheric predictability in the austral cold season when the southern sea ice cover is rapidly expanding.

Free access