10:50 AM - 11:05 AM
[ACG44-01] Studies on variabilities of the Kuroshio and water masses based on shipboard observations, Argo floats, and numerical models.
★Invited Papers
Keywords:hydrographic observations, Argo floats, ocean models, Kuroshio, water masses
In the North Pacific subtropical gyre, the Kuroshio flows in the western boundary region and water masses such as North Pacific subtropical mode water (Masuzawa, 1969), North Pacific central mode water (Nakamura, 1996; Suga et al., 1997), and North Pacific tropical water (Cannon, 1966) are widely distributed. Since the Kuroshio transports large amounts of seawater and heat, and water masses occupy huge volume in the subsurface, these are considered to be keys to understand 3-dimensional temperature/salinity (T/S) distributions in the subtropical gyre.
We have been examined upper ocean variability in the North Pacific subtropical gyre, based on hydrographic observations by the Japan Meteorological Agency (JMA) (repeat hydrographic sections along 137ºE and 165ºE) and Argo float profiles. For example, temporal variations of net Kuroshio transport on various timescales and significant freshening in the main thermocline/halocline were reported from the hydrographic sections by the JMA (Kawakami et al., 2020; Kawakami et al., 2022). On the other hand, T/S profiles obtained by Argo floats were analyzed to three-dimensionally investigate temporal variations of water mass formation and distribution (Kawakami et al., 2016).
Further, we also used an ocean model to understand a relationship between the upper ocean variability and atmospheric forcing. We showed that variabilities of the Kuroshio and water masses are mostly attributable to the atmospheric forcing in the cold season by performing sensitivity experiments (Kawakami et al., 2023).
In this presentation, we will introduce the above researches, and discuss the strength and complementarity of data obtained from various platforms and possibility of combination studies of observations and model experiments.
We have been examined upper ocean variability in the North Pacific subtropical gyre, based on hydrographic observations by the Japan Meteorological Agency (JMA) (repeat hydrographic sections along 137ºE and 165ºE) and Argo float profiles. For example, temporal variations of net Kuroshio transport on various timescales and significant freshening in the main thermocline/halocline were reported from the hydrographic sections by the JMA (Kawakami et al., 2020; Kawakami et al., 2022). On the other hand, T/S profiles obtained by Argo floats were analyzed to three-dimensionally investigate temporal variations of water mass formation and distribution (Kawakami et al., 2016).
Further, we also used an ocean model to understand a relationship between the upper ocean variability and atmospheric forcing. We showed that variabilities of the Kuroshio and water masses are mostly attributable to the atmospheric forcing in the cold season by performing sensitivity experiments (Kawakami et al., 2023).
In this presentation, we will introduce the above researches, and discuss the strength and complementarity of data obtained from various platforms and possibility of combination studies of observations and model experiments.