The Wake of Hurricane Allen in the Western Gulf of Mexico

Observed strong currents under global tropical cyclones

“…The first one is by deploying airborne drifting or profiling instruments, such as expendable current profilers (AXCPs), electromagnetic-autonomous profiling explorer (EM-APEX) floats, surface drifters or Lagrangian floats (Price et al, 1994;D'Asaro et al, 2007;Sanford et al, 2011) ahead of a target hurricane. The second method of observing ocean current response to TCs is by using data collected from current meter mooring or shore-based high frequency radar during the passage of hurricanes (Brooks, 1983;Teague et al, 2007;Jaimes and Shay, 2009;Black and Dickey, 2008). Both methods provide direct measurements of ocean currents and thermal structure in response to a moving TC, and the various factors of the ocean thermal structure which affect this response can be discussed separately.…”

Features of near-inertial motions observed on the northern South China Sea shelf during the passage of two typhoons

“…D 'Asaro, 1985), with a speed peak usually over 30 cm/s and with a decay time scale of more than 5 days (e.g. Brooks, 1983;Chen et al, 1996).…”

Observed near-surface currents under four super typhoons

“…Traditionally, the ocean OML currents during typhoon passage are mainly determined by the wind stress with a maximum current speed located to the right of the storm track at~1-2R max (Brooks, 1983;Chang et al, 2013). Within this range the linear regression was conducted between U obs (unit: m s −1 ) on the right side of the storm center (45°≦ Direction ≦ 135°, see Table 3) and U h at D~1-2 R max (D = 38-95 km, see Table 3), m s −1 , the corresponding current velocities at~1-2 R max are approximately 2.5 ± 0.6, 2.2 ± 0.6, 2.0 ± 0.5, 1.7 ± 0.5, 1.5 ± 0.6, and 1.2 ± 0.6 m s −1 .…”

“…Direct current measurements under TCs during their passages include moored current meters, airborne expendable current profilers (AXCPs), drifting buoys, electromagneticautonomous profiling explorer (EM-APEX) floats, Surface Velocity Program (SVP) (Niiler, 2001) drifters, and acoustic Doppler current profilers (ADCPs). Maximum current velocities of 0.3-1.0 m s −1 were observed from earlier current meter moorings in the ocean mixed layer (OML) and thermocline as hurricanes passing by within about 60-100 km of these moorings (Brink, 1989;Brooks, 1983;Dickey et al, 1998;Shay and Elsberry, 1987). Strong rightward-biased currents in the upper OML were identified from 0.8 to 1.7 m s −1 from AXCPs under tropical storm (TS), category-1, category-3, and category-4 hurricanes (Price et al, 1994;Sanford et al, 1987;Shay and Uhlhorn, 2008), and from 1.0 to 1.5 m s −1 from 3 profiling EM-APEX floats under category-4 hurricane Frances 2004 Sanford et al, 2011).…”

“…The typhoon wind-forcing on the ocean mixed layer (OML) currents is near-resonant on the right side but not on the left side of the track (Price, 1981(Price, , 1983Price et al, 1994). Thus, the OML currents are mainly determined by the wind stress with maximum current speed to the right of the storm track at the distance of 1-2R max (mean R max = 47 km) (Brooks, 1983;Chang et al, 2013;Hsu and Yana, 1998). Questions arise: What are the characteristics of OML currents to the right of the storm track at~1-2R max under category-5 super typhoons from direct velocity measurements?…”