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  • Author or Editor: Iossif Lozovatsky x
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Vadim T. Paka
,
Valeri N. Nabatov
,
Iossif D. Lozovatsky
, and
Tomas M. Dillon

Abstract

The authors describe instruments and their calibration techniques developed at the Atlantic Branch of the P. P. Shizshov Institute of Oceanology, Russian Academy of Sciences and used for microstructure measurements by Russian oceanographers during the last decade. The vertical profiler BAKLAN and the towing body GRIF carried among other sensors a new microconductivity capillary probe with spectral resolution O(100 cpm). This sensor was used to calculate the scalar dissipation rate χ with noise level of 3 × 10−10 K2 s−1. The kinetic energy dissipation rate ɛ was measured by an airfoil-type sensor with a noise level less than 8 × 10−10 W kg−1. Results of the measurements are illustrated by the data obtained near the California coast and in the western equatorial Pacific. A parameterization of equatorial turbulence in terms of turbulent diffusivities and the gradient Richardson numbers is considered. A relationship between horizontal patchiness of conductivity microstructure in the coastal zone and local thermohaline fronts was detected.

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Hemantha W. Wijesekera
,
Emily Shroyer
,
Amit Tandon
,
M. Ravichandran
,
Debasis Sengupta
,
S. U. P. Jinadasa
,
Harindra J. S. Fernando
,
Neeraj Agrawal
,
K. Arulananthan
,
G. S. Bhat
,
Mark Baumgartner
,
Jared Buckley
,
Luca Centurioni
,
Patrick Conry
,
J. Thomas Farrar
,
Arnold L. Gordon
,
Verena Hormann
,
Ewa Jarosz
,
Tommy G. Jensen
,
Shaun Johnston
,
Matthias Lankhorst
,
Craig M. Lee
,
Laura S. Leo
,
Iossif Lozovatsky
,
Andrew J. Lucas
,
Jennifer Mackinnon
,
Amala Mahadevan
,
Jonathan Nash
,
Melissa M. Omand
,
Hieu Pham
,
Robert Pinkel
,
Luc Rainville
,
Sanjiv Ramachandran
,
Daniel L. Rudnick
,
Sutanu Sarkar
,
Uwe Send
,
Rashmi Sharma
,
Harper Simmons
,
Kathleen M. Stafford
,
Louis St. Laurent
,
Karan Venayagamoorthy
,
Ramasamy Venkatesan
,
William J. Teague
,
David W. Wang
,
Amy F. Waterhouse
,
Robert Weller
, and
Caitlin B. Whalen

Abstract

Air–Sea Interactions in the Northern Indian Ocean (ASIRI) is an international research effort (2013–17) aimed at understanding and quantifying coupled atmosphere–ocean dynamics of the Bay of Bengal (BoB) with relevance to Indian Ocean monsoons. Working collaboratively, more than 20 research institutions are acquiring field observations coupled with operational and high-resolution models to address scientific issues that have stymied the monsoon predictability. ASIRI combines new and mature observational technologies to resolve submesoscale to regional-scale currents and hydrophysical fields. These data reveal BoB’s sharp frontal features, submesoscale variability, low-salinity lenses and filaments, and shallow mixed layers, with relatively weak turbulent mixing. Observed physical features include energetic high-frequency internal waves in the southern BoB, energetic mesoscale and submesoscale features including an intrathermocline eddy in the central BoB, and a high-resolution view of the exchange along the periphery of Sri Lanka, which includes the 100-km-wide East India Coastal Current (EICC) carrying low-salinity water out of the BoB and an adjacent, broad northward flow (∼300 km wide) that carries high-salinity water into BoB during the northeast monsoon. Atmospheric boundary layer (ABL) observations during the decaying phase of the Madden–Julian oscillation (MJO) permit the study of multiscale atmospheric processes associated with non-MJO phenomena and their impacts on the marine boundary layer. Underway analyses that integrate observations and numerical simulations shed light on how air–sea interactions control the ABL and upper-ocean processes.

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Qing Wang
,
Denny P. Alappattu
,
Stephanie Billingsley
,
Byron Blomquist
,
Robert J. Burkholder
,
Adam J. Christman
,
Edward D. Creegan
,
Tony de Paolo
,
Daniel P. Eleuterio
,
Harindra Joseph S. Fernando
,
Kyle B. Franklin
,
Andrey A. Grachev
,
Tracy Haack
,
Thomas R. Hanley
,
Christopher M. Hocut
,
Teddy R. Holt
,
Kate Horgan
,
Haflidi H. Jonsson
,
Robert A. Hale
,
John A. Kalogiros
,
Djamal Khelif
,
Laura S. Leo
,
Richard J. Lind
,
Iossif Lozovatsky
,
Jesus Planella-Morato
,
Swagato Mukherjee
,
Wendell A. Nuss
,
Jonathan Pozderac
,
L. Ted Rogers
,
Ivan Savelyev
,
Dana K. Savidge
,
R. Kipp Shearman
,
Lian Shen
,
Eric Terrill
,
A. Marcela Ulate
,
Qi Wang
,
R. Travis Wendt
,
Russell Wiss
,
Roy K. Woods
,
Luyao Xu
,
Ryan T. Yamaguchi
, and
Caglar Yardim

Abstract

The Coupled Air–Sea Processes and Electromagnetic Ducting Research (CASPER) project aims to better quantify atmospheric effects on the propagation of radar and communication signals in the marine environment. Such effects are associated with vertical gradients of temperature and water vapor in the marine atmospheric surface layer (MASL) and in the capping inversion of the marine atmospheric boundary layer (MABL), as well as the horizontal variations of these vertical gradients. CASPER field measurements emphasized simultaneous characterization of electromagnetic (EM) wave propagation, the propagation environment, and the physical processes that gave rise to the measured refractivity conditions. CASPER modeling efforts utilized state-of-the-art large-eddy simulations (LESs) with a dynamically coupled MASL and phase-resolved ocean surface waves. CASPER-East was the first of two planned field campaigns, conducted in October and November 2015 offshore of Duck, North Carolina. This article highlights the scientific motivations and objectives of CASPER and provides an overview of the CASPER-East field campaign. The CASPER-East sampling strategy enabled us to obtain EM wave propagation loss as well as concurrent environmental refractive conditions along the propagation path. This article highlights the initial results from this sampling strategy showing the range-dependent propagation loss, the atmospheric and upper-oceanic variability along the propagation range, and the MASL thermodynamic profiles measured during CASPER-East.

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