10:45 AM - 12:15 PM
[ACG44-P10] Recent variability of ocean heat storage using a gridded dataset MOAA GPV based on Argo float data
Keywords:Ocean Heat Content, OneArgo, seasonal and inter-annual variability
The accumulated heat in the Earth's surface layer due to the global warming is mainly sinking into the sea surface, and it has been reported that the oceanic heat energy is already penetrated largely from the surface to the deeper layer (IPCC, 2021). Associated with the oceanic heat content (OHC), linear trends in OHC are also investigated, with error bars, based on a recent increase in observational data such as Argo (Schuckmann et al., 2023). However, the mechanisms of OHC is not yet clear. For example, the hiatus that slowdown temperature increase in the world from 2000 to the early 2010s might be related to a decrease of sea surface temperature, but there are still many theories even though many studies using climate models have been conducted. In this study, we attempt to statistically show the characteristics of variability in OHC during and after recent hiatus based on observations with the dataset of 10-day gridded MOAA GPV (ver. 2), which has used the accumulated Argo float data for more than 20 years.
The slowdown of temperature increase noted in previous studies in the surface to sub-surface is shown mainly in the tropics and the Northern Hemisphere. In the Southern Hemisphere, on the other hand, the timing of the increase of OHC trend appears to be slightly earlier, with OHC beginning in the late 2000s. While the tendency is clearly evident above 700 m, it is hardly detected below 700m except in the Atlantic Ocean. The seasonal and intra-seasonal variations in OHC are also of the same order of magnitude or greater than the OHC trend in each region, suggesting that the shorter timescale variability is potentially important to the inter-annual changes in OHC. The detailed characteristics of OHC variability including the seasonal and intra-seasonal variability will be presented.
The slowdown of temperature increase noted in previous studies in the surface to sub-surface is shown mainly in the tropics and the Northern Hemisphere. In the Southern Hemisphere, on the other hand, the timing of the increase of OHC trend appears to be slightly earlier, with OHC beginning in the late 2000s. While the tendency is clearly evident above 700 m, it is hardly detected below 700m except in the Atlantic Ocean. The seasonal and intra-seasonal variations in OHC are also of the same order of magnitude or greater than the OHC trend in each region, suggesting that the shorter timescale variability is potentially important to the inter-annual changes in OHC. The detailed characteristics of OHC variability including the seasonal and intra-seasonal variability will be presented.