Near-Real-Time Availability of Ocean Heat Content Over the North Indian Ocean

Abstract

Ocean heat content (OHC) is an important parameter in determining the heat flux in the ocean–atmosphere system, which can influence weather systems such as cyclones and monsoons. Hence, regular monitoring of OHC is required, which needs continuous subsurface temperature profiles. Due to the scarcity of <bold xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><i>in situ</i> </b> temperature profiles in space and time, remotely sensed sea surface temperature (SST) and sea surface height anomalies (SSHAs) are employed in the computation of OHC in the Indian Ocean. OHC derived from <bold xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><i>in situ </i></b> temperature profiles from ARGO floats along with collocated SST, SSHA and OHC climatology during the period 2002–2012 are used to estimate <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\text{OHC}_{700} $</tex-math></inline-formula> (heat content up to 700-m depth), using an artificial neural network model. The estimated <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\text{OHC}_{700} $</tex-math></inline-formula> is validated and is found to be significantly correlated with the observed <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\text{OHC}_{700}$</tex-math></inline-formula> . Using this approach, <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\text{OHC}_{700} $</tex-math></inline-formula> is being estimated daily on a near-real-time basis, and the products are available at <uri xlink:type="simple" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">http://bhuvan.nrsc.gov.in/data/download/index.php</uri> .