[Todos] Seminario CSC-Giol: Data Assimilation for Detection and Attribution of Climate Change

[Esteban Mocskos]

Lugar: Godoy Cruz 2390 1er piso
Fecha: martes 18 de marzo 11hs

Title: Data Assimilation for Detection and Attribution of Climate Change
(DADA)

Abstract: How can climate observations be used to best evidence the
influence on climate of human activities, among other forcings?
Statistical methods of Detection and Attribution (D&A) were designed
to answer this question. Conventional D&A methods are based on linear
regression of spatial or temporal patterns extracted from one or
several climate models. On the other hand, how can observations be
used to best constrain a numerical model's state variables and
parameters? Methods of Data Assimilation (DA) meet this general
purpose. Could D&A methods take advantage of recent progresses in DA?
We discuss this general idea and illustrate it qualitatively by
applying a simple data assimilation algorithm (AEKF) to a 1D radiative
column model. The model simulates the vertical temperature structure
of the atmosphere resulting from prescribed vertical profiles of key
optical properties, as well as its dynamics when these optical
properties are affected by changes in atmospheric constituents. In
particular, it allows to represent the characteristic pattern of
cooling of the stratosphere and warming of the troposphere under
greenhouse gas forcing - an important historical fingerprint in D&A.
We show that it is possible to reconstruct these forcings from the
observation of the evolution of the vertical temperature profile based
on data assimilation and thereby to evidence the influence of
anthropogenic forcing on the evolution of climate.


Dr. Hannart is a climate scientist from CNRS working at the Instituto
Franco-Argentino sobre Estudios de Clima y sus Impactos (UMI-IFAECI).