The sensitivity of upper ocean structure to time varying wind direction

Abstract

Observations and models show that sudden changes in the magnitude of the wind stress which occur within a time interval of one‐half inertial period are most effective in increasing surface current speeds and mixing the upper layers of the ocean. The purpose of the present study is to quantify the effects of concurrent time dependent wind direction. The Mellor‐Yamada level 2 1/2 turbulence closure model is used. A series of model runs was executed in order to determine the relative sensitivity of mixed layer depth and sea surface temperature to wind speed as compared with the rate of change of wind direction. The results indicate that the accuracy and time resolution of wind direction should be given special consideration in the design and interpretation of field experiments which will be used for testing prognostic mixed layer models.

Investigation of the biophysical processes over the oligotrophic waters of South Indian Ocean subtropical gyre, triggered by cyclone Edzani

“…5). This observation is well supported by previous works (Dickey and Simpson, 1983;Stramma et al, 1986;Sanford et al, 1987) indicate sea surface cooling is intense on the left side (right side in the Northern Hemisphere) of the storm track. The mixed layer deepening was maximum on 12th January 2010 as observed from Argo ID-33146, located close to the cyclone track.…”

Relationship between Interannual Variability of Phytoplankton and Tropical Cyclones in the Western North Pacific

“…The role of TCs on the ocean is well documented in previous studies (Hazelworth 1968;Dickey and Simpson 1983;Stramma et al 1986). The cyclonic system of TCs produces Ekman pumping, shear-induced entrainment mixing, and the deepening of mixed layers.…”

Quantitative effects of pycnocline and dissolved oxygen on vertical distribution of moon jellyfish Aurelia aurita s.l.: a case study of Mikawa Bay, Japan

“…4d, 7c). It is well known that extremely strong wind events, such as typhoons and hurricanes, induce vertical mixing (Dickey & Simpson, 1983), and this mixing would temporarily weaken or eliminate hypoxic waters (Hagy et al, 2006;Rasul et al, 2013). Thus, it is suggested that the higher incidence of typhoons in 2011 resulted in a lower degree of bottom DO depletion and an LLD closer to the bottom compared to the other years.…”