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James F. Black and Barry L. Tarmy

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James F. Black and Barry L. Tarmy

Abstract

Calculations are presented which suggest that useful amounts of rainfall might be produced economically in and regions near seas or lakes. The proposed technique involves the coating of a large area with asphalt to produce thermal updrafts which increase the sea breeze circulation and promote condensation. Calculations based upon previously developed models of the air flow over heated islands suggest that 2 to 3 acres of arable land could be produced per acre of asphalt and that the cost of the rainfall produced would he of the order of 3¢ per 1000 gal or $9.00 per acre ft. The sensitivity of these conclusions to changes in the various assumptions involved in the calculations is discussed.

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Thomas B. Sanford, Peter G. Black, James R. Haustein, James W. Feeney, George Z. Forristall, and James F. Price

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The response of the ocean to hurricanes was investigated using aircraft-deployable expendable current profilers (AXCP). The goals were to observe and separate the surface wave and surface mixed layer (SML) velocities under the storms and to map the across-track and along-track velocity and temperature response in the mixed layer and thermocline. Custom instrumentation was prepared, including slower failing AXCPs, and the AXCP equipment was installed on NOAA WP-3D aircraft. Research flights were made into two 1984 hurricanes: Norbert, in the eastern Pacific off Baja California (19°N, 109°W), and Josephine, off the east coast of the United States (29°N, 72°W). Thirty-one probes were deployed in each hurricane, and about half the AXCPs provided temperature and velocity profiles. Most velocity profiles exhibited strong surface wave contributions, slablike velocities in the SML, strong shears beneath the SML, and only weak flows in the upper thermocline. Separation of the surface gravity wave velocities from the steady and inertial motions was obtained by fitting the profiles to steady flows and shears in three layers and to a single surface wave at all levels. The velocity profiles displayed large divergences to the horizontal SML velocities in the wake of the hurricanes. The observations show a strong enhancement of SML velocities to the right of the storm as expected from numerical simulations. The largest SML velocities were 1.1 m s−1 in Norbert and 0.73 m s−1in Josephine. Numerical simulations will be compared with the observations in Part II.

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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.

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