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A. J. Illingworth
,
A. Battaglia
,
J. Bradford
,
M. Forsythe
,
P. Joe
,
P. Kollias
,
K. Lean
,
M. Lori
,
J.-F. Mahfouf
,
S. Melo
,
R Midthassel
,
Y. Munro
,
J. Nicol
,
R. Potthast
,
M. Rennie
,
T. H. M. Stein
,
S. Tanelli
,
F. Tridon
,
C. J. Walden
, and
M. Wolde

Abstract

This paper presents a conically scanning spaceborne Dopplerized 94-GHz radar Earth science mission concept: Wind Velocity Radar Nephoscope (WIVERN). WIVERN aims to provide global measurements of in-cloud winds using the Doppler-shifted radar returns from hydrometeors. The conically scanning radar could provide wind data with daily revisits poleward of 50°, 50-km horizontal resolution, and approximately 1-km vertical resolution. The measured winds, when assimilated into weather forecasts and provided they are representative of the larger-scale mean flow, should lead to further improvements in the accuracy and effectiveness of forecasts of severe weather and better focusing of activities to limit damage and loss of life. It should also be possible to characterize the more variable winds associated with local convection. Polarization diversity would be used to enable high wind speeds to be unambiguously observed; analysis indicates that artifacts associated with polarization diversity are rare and can be identified. Winds should be measurable down to 1 km above the ocean surface and 2 km over land. The potential impact of the WIVERN winds on reducing forecast errors is estimated by comparison with the known positive impact of cloud motion and aircraft winds. The main thrust of WIVERN is observing in-cloud winds, but WIVERN should also provide global estimates of ice water content, cloud cover, and vertical distribution, continuing the data series started by CloudSat with the conical scan giving increased coverage. As with CloudSat, estimates of rainfall and snowfall rates should be possible. These nonwind products may also have a positive impact when assimilated into weather forecasts.

Open access
James D. Doyle
,
Jonathan R. Moskaitis
,
Joel W. Feldmeier
,
Ronald J. Ferek
,
Mark Beaubien
,
Michael M. Bell
,
Daniel L. Cecil
,
Robert L. Creasey
,
Patrick Duran
,
Russell L. Elsberry
,
William A. Komaromi
,
John Molinari
,
David R. Ryglicki
,
Daniel P. Stern
,
Christopher S. Velden
,
Xuguang Wang
,
Todd Allen
,
Bradford S. Barrett
,
Peter G. Black
,
Jason P. Dunion
,
Kerry A. Emanuel
,
Patrick A. Harr
,
Lee Harrison
,
Eric A. Hendricks
,
Derrick Herndon
,
William Q. Jeffries
,
Sharanya J. Majumdar
,
James A. Moore
,
Zhaoxia Pu
,
Robert F. Rogers
,
Elizabeth R. Sanabia
,
Gregory J. Tripoli
, and
Da-Lin Zhang

Abstract

Tropical cyclone (TC) outflow and its relationship to TC intensity change and structure were investigated in the Office of Naval Research Tropical Cyclone Intensity (TCI) field program during 2015 using dropsondes deployed from the innovative new High-Definition Sounding System (HDSS) and remotely sensed observations from the Hurricane Imaging Radiometer (HIRAD), both on board the NASA WB-57 that flew in the lower stratosphere. Three noteworthy hurricanes were intensively observed with unprecedented horizontal resolution: Joaquin in the Atlantic and Marty and Patricia in the eastern North Pacific. Nearly 800 dropsondes were deployed from the WB-57 flight level of ∼60,000 ft (∼18 km), recording atmospheric conditions from the lower stratosphere to the surface, while HIRAD measured the surface winds in a 50-km-wide swath with a horizontal resolution of 2 km. Dropsonde transects with 4–10-km spacing through the inner cores of Hurricanes Patricia, Joaquin, and Marty depict the large horizontal and vertical gradients in winds and thermodynamic properties. An innovative technique utilizing GPS positions of the HDSS reveals the vortex tilt in detail not possible before. In four TCI flights over Joaquin, systematic measurements of a major hurricane’s outflow layer were made at high spatial resolution for the first time. Dropsondes deployed at 4-km intervals as the WB-57 flew over the center of Hurricane Patricia reveal in unprecedented detail the inner-core structure and upper-tropospheric outflow associated with this historic hurricane. Analyses and numerical modeling studies are in progress to understand and predict the complex factors that influenced Joaquin’s and Patricia’s unusual intensity changes.

Open access