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  • Author or Editor: Richard G. Williams x
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Nilton O. Rennó
,
Earle Williams
,
Daniel Rosenfeld
,
David G. Fischer
,
Jürgen Fischer
,
Tibor Kremic
,
Arun Agrawal
,
Meinrat O. Andreae
,
Rosina Bierbaum
,
Richard Blakeslee
,
Anko Boerner
,
Neil Bowles
,
Hugh Christian
,
Ann Cox
,
Jason Dunion
,
Akos Horvath
,
Xianglei Huang
,
Alexander Khain
,
Stefan Kinne
,
Maria C. Lemos
,
Joyce E. Penner
,
Ulrich Pöschl
,
Johannes Quaas
,
Elena Seran
,
Bjorn Stevens
,
Thomas Walati
, and
Thomas Wagner

The formation of cloud droplets on aerosol particles, technically known as the activation of cloud condensation nuclei (CCN), is the fundamental process driving the interactions of aerosols with clouds and precipitation. The Intergovernmental Panel on Climate Change (IPCC) and the Decadal Survey indicate that the uncertainty in how clouds adjust to aerosol perturbations dominates the uncertainty in the overall quantification of the radiative forcing attributable to human activities.

Measurements by current satellites allow the determination of crude profiles of cloud particle size, but not of the activated CCN that seed them. The Clouds, Hazards, and Aerosols Survey for Earth Researchers (CHASER) mission concept responds to the IPCC and Decadal Survey concerns, utilizing a new technique and high-heritage instruments to measure all the quantities necessary to produce the first global survey maps of activated CCN and the properties of the clouds associated with them. CHASER also determines the activated CCN concentration and cloud thermodynamic forcing simultaneously, allowing the effects of each to be distinguished.

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M. Susan Lozier
,
Sheldon Bacon
,
Amy S. Bower
,
Stuart A. Cunningham
,
M. Femke de Jong
,
Laura de Steur
,
Brad deYoung
,
Jürgen Fischer
,
Stefan F. Gary
,
Blair J. W. Greenan
,
Patrick Heimbach
,
Naomi P. Holliday
,
Loïc Houpert
,
Mark E. Inall
,
William E. Johns
,
Helen L. Johnson
,
Johannes Karstensen
,
Feili Li
,
Xiaopei Lin
,
Neill Mackay
,
David P. Marshall
,
Herlé Mercier
,
Paul G. Myers
,
Robert S. Pickart
,
Helen R. Pillar
,
Fiammetta Straneo
,
Virginie Thierry
,
Robert A. Weller
,
Richard G. Williams
,
Chris Wilson
,
Jiayan Yang
,
Jian Zhao
, and
Jan D. Zika

Abstract

For decades oceanographers have understood the Atlantic meridional overturning circulation (AMOC) to be primarily driven by changes in the production of deep-water formation in the subpolar and subarctic North Atlantic. Indeed, current Intergovernmental Panel on Climate Change (IPCC) projections of an AMOC slowdown in the twenty-first century based on climate models are attributed to the inhibition of deep convection in the North Atlantic. However, observational evidence for this linkage has been elusive: there has been no clear demonstration of AMOC variability in response to changes in deep-water formation. The motivation for understanding this linkage is compelling, since the overturning circulation has been shown to sequester heat and anthropogenic carbon in the deep ocean. Furthermore, AMOC variability is expected to impact this sequestration as well as have consequences for regional and global climates through its effect on the poleward transport of warm water. Motivated by the need for a mechanistic understanding of the AMOC, an international community has assembled an observing system, Overturning in the Subpolar North Atlantic Program (OSNAP), to provide a continuous record of the transbasin fluxes of heat, mass, and freshwater, and to link that record to convective activity and water mass transformation at high latitudes. OSNAP, in conjunction with the Rapid Climate Change–Meridional Overturning Circulation and Heatflux Array (RAPID–MOCHA) at 26°N and other observational elements, will provide a comprehensive measure of the three-dimensional AMOC and an understanding of what drives its variability. The OSNAP observing system was fully deployed in the summer of 2014, and the first OSNAP data products are expected in the fall of 2017.

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David C. Fritts
,
Ronald B. Smith
,
Michael J. Taylor
,
James D. Doyle
,
Stephen D. Eckermann
,
Andreas Dörnbrack
,
Markus Rapp
,
Bifford P. Williams
,
P.-Dominique Pautet
,
Katrina Bossert
,
Neal R. Criddle
,
Carolyn A. Reynolds
,
P. Alex Reinecke
,
Michael Uddstrom
,
Michael J. Revell
,
Richard Turner
,
Bernd Kaifler
,
Johannes S. Wagner
,
Tyler Mixa
,
Christopher G. Kruse
,
Alison D. Nugent
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Campbell D. Watson
,
Sonja Gisinger
,
Steven M. Smith
,
Ruth S. Lieberman
,
Brian Laughman
,
James J. Moore
,
William O. Brown
,
Julie A. Haggerty
,
Alison Rockwell
,
Gregory J. Stossmeister
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Steven F. Williams
,
Gonzalo Hernandez
,
Damian J. Murphy
,
Andrew R. Klekociuk
,
Iain M. Reid
, and
Jun Ma

Abstract

The Deep Propagating Gravity Wave Experiment (DEEPWAVE) was designed to quantify gravity wave (GW) dynamics and effects from orographic and other sources to regions of dissipation at high altitudes. The core DEEPWAVE field phase took place from May through July 2014 using a comprehensive suite of airborne and ground-based instruments providing measurements from Earth’s surface to ∼100 km. Austral winter was chosen to observe deep GW propagation to high altitudes. DEEPWAVE was based on South Island, New Zealand, to provide access to the New Zealand and Tasmanian “hotspots” of GW activity and additional GW sources over the Southern Ocean and Tasman Sea. To observe GWs up to ∼100 km, DEEPWAVE utilized three new instruments built specifically for the National Science Foundation (NSF)/National Center for Atmospheric Research (NCAR) Gulfstream V (GV): a Rayleigh lidar, a sodium resonance lidar, and an advanced mesosphere temperature mapper. These measurements were supplemented by in situ probes, dropsondes, and a microwave temperature profiler on the GV and by in situ probes and a Doppler lidar aboard the German DLR Falcon. Extensive ground-based instrumentation and radiosondes were deployed on South Island, Tasmania, and Southern Ocean islands. Deep orographic GWs were a primary target but multiple flights also observed deep GWs arising from deep convection, jet streams, and frontal systems. Highlights include the following: 1) strong orographic GW forcing accompanying strong cross-mountain flows, 2) strong high-altitude responses even when orographic forcing was weak, 3) large-scale GWs at high altitudes arising from jet stream sources, and 4) significant flight-level energy fluxes and often very large momentum fluxes at high altitudes.

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Gregory C. Johnson
,
Rick Lumpkin
,
Tim Boyer
,
Francis Bringas
,
Ivona Cetinić
,
Don P. Chambers
,
Lijing Cheng
,
Shenfu Dong
,
Richard A. Feely
,
Baylor Fox-Kemper
,
Eleanor Frajka-Williams
,
Bryan A. Franz
,
Yao Fu
,
Meng Gao
,
Jay Garg
,
John Gilson
,
Gustavo Goni
,
Benjamin D. Hamlington
,
Helene T. Hewitt
,
William R. Hobbs
,
Zeng-Zhen Hu
,
Boyin Huang
,
Svetlana Jevrejeva
,
William E. Johns
,
Sato Katsunari
,
John J. Kennedy
,
Marion Kersalé
,
Rachel E. Killick
,
Eric Leuliette
,
Ricardo Locarnini
,
M. Susan Lozier
,
John M. Lyman
,
Mark A. Merrifield
,
Alexey Mishonov
,
Gary T. Mitchum
,
Ben I. Moat
,
R. Steven Nerem
,
Dirk Notz
,
Renellys C. Perez
,
Sarah G. Purkey
,
Darren Rayner
,
James Reagan
,
Claudia Schmid
,
David A. Siegel
,
David A. Smeed
,
Paul W. Stackhouse
,
William Sweet
,
Philip R. Thompson
,
Denis L. Volkov
,
Rik Wanninkhof
,
Robert A. Weller
,
Caihong Wen
,
Toby K. Westberry
,
Matthew J. Widlansky
,
Josh K. Willis
,
Lisan Yu
, and
Huai-Min Zhang
Free access
Gregory C. Johnson
,
Rick Lumpkin
,
Simone R. Alin
,
Dillon J. Amaya
,
Molly O. Baringer
,
Tim Boyer
,
Peter Brandt
,
Brendan R. Carter
,
Ivona Cetinić
,
Don P. Chambers
,
Lijing Cheng
,
Andrew U. Collins
,
Cathy Cosca
,
Ricardo Domingues
,
Shenfu Dong
,
Richard A. Feely
,
Eleanor Frajka-Williams
,
Bryan A. Franz
,
John Gilson
,
Gustavo Goni
,
Benjamin D. Hamlington
,
Josefine Herrford
,
Zeng-Zhen Hu
,
Boyin Huang
,
Masayoshi Ishii
,
Svetlana Jevrejeva
,
John J. Kennedy
,
Marion Kersalé
,
Rachel E. Killick
,
Peter Landschützer
,
Matthias Lankhorst
,
Eric Leuliette
,
Ricardo Locarnini
,
John M. Lyman
,
John J. Marra
,
Christopher S. Meinen
,
Mark A. Merrifield
,
Gary T. Mitchum
,
Ben I. Moat
,
R. Steven Nerem
,
Renellys C. Perez
,
Sarah G. Purkey
,
James Reagan
,
Alejandra Sanchez-Franks
,
Hillary A. Scannell
,
Claudia Schmid
,
Joel P. Scott
,
David A. Siegel
,
David A. Smeed
,
Paul W. Stackhouse
,
William Sweet
,
Philip R. Thompson
,
Joaquin A. Triñanes
,
Denis L. Volkov
,
Rik Wanninkhof
,
Robert A. Weller
,
Caihong Wen
,
Toby K. Westberry
,
Matthew J. Widlansky
,
Anne C. Wilber
,
Lisan Yu
, and
Huai-Min Zhang
Free access
Molly Baringer
,
Mariana B. Bif
,
Tim Boyer
,
Seth M. Bushinsky
,
Brendan R. Carter
,
Ivona Cetinić
,
Don P. Chambers
,
Lijing Cheng
,
Sanai Chiba
,
Minhan Dai
,
Catia M. Domingues
,
Shenfu Dong
,
Andrea J. Fassbender
,
Richard A. Feely
,
Eleanor Frajka-Williams
,
Bryan A. Franz
,
John Gilson
,
Gustavo Goni
,
Benjamin D. Hamlington
,
Zeng-Zhen Hu
,
Boyin Huang
,
Masayoshi Ishii
,
Svetlana Jevrejeva
,
William E. Johns
,
Gregory C. Johnson
,
Kenneth S. Johnson
,
John Kennedy
,
Marion Kersalé
,
Rachel E. Killick
,
Peter Landschützer
,
Matthias Lankhorst
,
Tong Lee
,
Eric Leuliette
,
Feili Li
,
Eric Lindstrom
,
Ricardo Locarnini
,
Susan Lozier
,
John M. Lyman
,
John J. Marra
,
Christopher S. Meinen
,
Mark A. Merrifield
,
Gary T. Mitchum
,
Ben Moat
,
Didier Monselesan
,
R. Steven Nerem
,
Renellys C. Perez
,
Sarah G. Purkey
,
Darren Rayner
,
James Reagan
,
Nicholas Rome
,
Alejandra Sanchez-Franks
,
Claudia Schmid
,
Joel P. Scott
,
Uwe Send
,
David A. Siegel
,
David A. Smeed
,
Sabrina Speich
,
Paul W. Stackhouse Jr.
,
William Sweet
,
Yuichiro Takeshita
,
Philip R. Thompson
,
Joaquin A. Triñanes
,
Martin Visbeck
,
Denis L. Volkov
,
Rik Wanninkhof
,
Robert A. Weller
,
Toby K. Westberry
,
Matthew J. Widlansky
,
Susan E. Wijffels
,
Anne C. Wilber
,
Lisan Yu
,
Weidong Yu
, and
Huai-Min Zhang
Free access
Robert J. H. Dunn
,
Freya Aldred
,
Nadine Gobron
,
John B. Miller
,
Kate M. Willett
,
Melanie Ades
,
Robert Adler
,
R. P. Allan
,
John Anderson
,
Orlane Anneville
,
Yasuyuki Aono
,
Anthony Argüez
,
Carlo Arosio
,
John A. Augustine
,
Cesar Azorin-Molina
,
Jonathan Barichivich
,
Aman Basu
,
Hylke E. Beck
,
Nicolas Bellouin
,
Angela Benedetti
,
Kevin Blagrave
,
Stephen Blenkinsop
,
Olivier Bock
,
Xavier Bodin
,
Michael G. Bosilovich
,
Olivier Boucher
,
Gerald Bove
,
Dennis Buechler
,
Stefan A. Buehler
,
Laura Carrea
,
Kai-Lan Chang
,
Hanne H. Christiansen
,
John R. Christy
,
Eui-Seok Chung
,
Laura M. Ciasto
,
Melanie Coldewey-Egbers
,
Owen R. Cooper
,
Richard C. Cornes
,
Curt Covey
,
Thomas Cropper
,
Molly Crotwell
,
Diego Cusicanqui
,
Sean M. Davis
,
Richard A. M. de Jeu
,
Doug Degenstein
,
Reynald Delaloye
,
Markus G. Donat
,
Wouter A. Dorigo
,
Imke Durre
,
Geoff S. Dutton
,
Gregory Duveiller
,
James W. Elkins
,
Thomas W. Estilow
,
Nava Fedaeff
,
David Fereday
,
Vitali E. Fioletov
,
Johannes Flemming
,
Michael J. Foster
,
Stacey M. Frith
,
Lucien Froidevaux
,
Martin Füllekrug
,
Judith Garforth
,
Jay Garg
,
Matthew Gentry
,
Steven Goodman
,
Qiqi Gou
,
Nikolay Granin
,
Mauro Guglielmin
,
Sebastian Hahn
,
Leopold Haimberger
,
Brad D. Hall
,
Ian Harris
,
Debbie L. Hemming
,
Martin Hirschi
,
Shu-pen (Ben) Ho
,
Robert Holzworth
,
Filip Hrbáček
,
Daan Hubert
,
Petra Hulsman
,
Dale F. Hurst
,
Antje Inness
,
Ketil Isaksen
,
Viju O. John
,
Philip D. Jones
,
Robert Junod
,
Andreas Kääb
,
Johannes W. Kaiser
,
Viktor Kaufmann
,
Andreas Kellerer-Pirklbauer
,
Elizabeth C. Kent
,
Richard Kidd
,
Hyungiun Kim
,
Zak Kipling
,
Akash Koppa
,
Jan Henning L’Abée-Lund
,
Xin Lan
,
Kathleen O. Lantz
,
David Lavers
,
Norman G. Loeb
,
Diego Loyola
,
Remi Madelon
,
Hilmar J. Malmquist
,
Wlodzimierz Marszelewski
,
Michael Mayer
,
Matthew F. McCabe
,
Tim R. McVicar
,
Carl A. Mears
,
Annette Menzel
,
Christopher J. Merchant
,
Diego G. Miralles
,
Stephen A. Montzka
,
Colin Morice
,
Leander Mösinger
,
Jens Mühle
,
Julien P. Nicolas
,
Jeannette Noetzli
,
Tiina Nõges
,
Ben Noll
,
John O’Keefe
,
Tim J. Osborn
,
Taejin Park
,
Cecile Pellet
,
Maury S. Pelto
,
Sarah E. Perkins-Kirkpatrick
,
Coda Phillips
,
Stephen Po-Chedley
,
Lorenzo Polvani
,
Wolfgang Preimesberger
,
Colin Price
,
Merja Pulkkanen
,
Dominik G. Rains
,
William J. Randel
,
Samuel Rémy
,
Lucrezia Ricciardulli
,
Andrew D. Richardson
,
David A. Robinson
,
Matthew Rodell
,
Nemesio J. Rodríguez-Fernández
,
Karen H. Rosenlof
,
Chris Roth
,
Alexei Rozanov
,
This Rutishäuser
,
Ahira Sánchez-Lugo
,
Parnchai Sawaengphokhai
,
Verena Schenzinger
,
Robert W. Schlegel
,
Udo Schneider
,
Sapna Sharma
,
Lei Shi
,
Adrian J. Simmons
,
Carolina Siso
,
Sharon L. Smith
,
Brian J. Soden
,
Viktoria Sofieva
,
Tim H. Sparks
,
Paul W. Stackhouse Jr.
,
Ryan Stauffer
,
Wolfgang Steinbrecht
,
Andrea K. Steiner
,
Kenton Stewart
,
Pietro Stradiotti
,
Dimitri A. Streletskiy
,
Hagen Telg
,
Stephen J. Thackeray
,
Emmanuel Thibert
,
Michael Todt
,
Daisuke Tokuda
,
Kleareti Tourpali
,
Mari R. Tye
,
Ronald van der A
,
Robin van der Schalie
,
Gerard van der Schrier
,
Mendy van der Vliet
,
Guido R. van der Werf
,
Arnold. van Vliet
,
Jean-Paul Vernier
,
Isaac J. Vimont
,
Katrina Virts
,
Sebastiàn Vivero
,
Holger Vömel
,
Russell S. Vose
,
Ray H. J. Wang
,
Markus Weber
,
David Wiese
,
Jeanette D. Wild
,
Earle Williams
,
Takmeng Wong
,
R. I. Woolway
,
Xungang Yin
,
Ye Yuan
,
Lin Zhao
,
Xinjia Zhou
,
Jerry R. Ziemke
,
Markus Ziese
, and
Ruxandra M. Zotta
Free access