A new approach to sensitivity climatologies: the DTS-MEDEX-2009 campaign

Abstract

Abstract.Adaptive observation is an approach to improving the quality of numerical weather forecasts through the optimization of observing networks. It is sometimes referred to as Data Targeting (DT). This approach has been applied to high impact weather during specific field campaigns in the past decade. Adaptive observations may involve various types of observations, including either specific research observing platforms or routine observing platforms employed in an adaptive way. The North-Atlantic TReC 2003 and the EURORISK-PREVIEW 2008 exercises focused on the North-Atlantic and Western Europe areas using mainly routine observing systems. These campaigns also included Mediterranean cases.The most recent campaign, DTS-MEDEX-2009, is the first campaign in which the DT method has been used to address exclusively Mediterranean high impact weather events. In this campaign, which is an important stage in the MEDEX development, only operational radiosonde stations and commercial aircraft data (AMDAR) have provided additional observations. Although specific diagnostic studies are needed to assess the impact of the extra-observations on forecast skill and demonstrate the effectiveness of DTS-MEDEX-2009, some preliminary findings can be deduced from a survey of this targeting exercise.After a description of the data targeting system and some illustrations of particular cases, this paper attempts some comparisons of additional observation needs (through effectively deployed radio-soundings) with sensitivity climatologies in the Mediterranean. The first step towards a sensitivity climatology for Mediterranean cases of high imCorrespondence to: A. Jansa (ajansac@aemet.es) pact weather is indirectly given by the frequency of extrasoundings launched from the network of radiosonde stations involved in the DTS-MEDEX-2009 campaign.

MEDEX: a general overview

“…4), MEDEX has produced a variety of tangible products. Regarding the MEDEX First Phase, the main output was the MEDEX database, as well as a comprehensive scientific summary (Buzzi et al, 2005) and a report for EUCOS about sensitivity computations (Jansa et al, 2004), besides a number of reports for the SSC/WWRP and for the MEDEX community. During the Second Phase, the main product was the performance of the MEDEX-2009-DTS campaign, as well as a second report for EUCOS (Jansa and Homar, 2006) about the results of sensitivity computations.…”

“…The main action of MEDEX in this line was the specific DTS-MEDEX-2009 campaign (see Jansa et al, 2011). This campaign was sponsored by EUCOS, which also provided organisation and facilities.…”

“…The first one (Jansa et al, 2004) includes initial studies, made in France and Spain, regarding the sensitivity to the initial conditions (IC) of the prediction of some cases as derived from adjoint models or indirectly through potential vorticity inversion. Other MEDEX studies are also mentioned in this report.…”

Influence of targeted observations on short-term forecasts of high-impact weather events in the Mediterranean

“…For autumn months (from 15 September to 19 December) data targeting was focused also on the Mediterranean basin. On autumn 2009 (from 11 September to 20 December), EUCOS supported the research field campaign of the Mediterranean experiment on cyclones that produces high-impact weather in the Mediterranean, in the so-called MEDEX-DTS (Jansà et al, 2011).…”

“…This objective was planned to be embodied in a field campaign. A first trial was framed into the PREVIEW Data Targeting System (DTS, Prates et al, 2009), and fully carried out for MEDEX-DTS (Jansà et al, 2011). This paper presents new results concerning different aspects of data targeting experimentation: the impact of targeted observations on short-range (1-2 days) forecasts of high-impact weather events in the Mediterranean, the usage of adaptive observations screening strategies within the DA system to ameliorate the satellite data sampling, and the assessment of the forecast skill of surface meteorological parameters of high social impact (rainfall, wind) in addition to that of upper-air variables.…”