A moist "available enthalpy" norm: definition and comparison with existing "energy" norms

TL;DR

This paper introduces a new moist-air norm based on the 'Available Enthalpy' approach, derived from thermodynamics, and compares it with existing energy norms used in atmospheric science for forecast analysis.

Contribution

It defines a novel moist-air norm rooted in thermodynamics and Exergy, offering a potentially improved tool for atmospheric error and sensitivity analysis.

Findings

New moist-air norm based on 'Available Enthalpy'

Comparison with existing energy norms shows promising impacts

Potential improvements in forecast error and sensitivity analysis

Abstract

Moist-air norms and inner-products are currently used in atmospheric science for computing dry or moist singular vectors and for determining forecast errors or sensitivity to observations based on tangent linear and adjoint models. A new moist-air norm is defined starting from old results published in Marquet (QJRMS 1993) and based on the "Available Enthalpy" approach, namely one of the Exergy function defined in general thermodynamics. Some interesting and promising impacts of this new "Available Enthalpy" norm are described in this brief version of a paper to be submitted to the QJRMS.