# Presentation: 556438

## T-NAWDEX

- THORPEX-
- North Atlantic Waveguide and Downstream Impact Experiment

**Andreas Dörnbrack and George Craig**
- Institut für Physik der Atmosphäre
- DLR Oberpfaffenhofen

**Sarah Jones**
- Institut für Meteorologie und Klimaforschung
- Universität Karlsruhe

**Heini Wernli**
- Institut für Physik der Atmosphäre
- Universität Mainz

## T-NAWDEX

**T-NAWDEX**
- THORPEX-
- North Atlantic Waveguide and Downstream Impact Experiment

- proposed by the working group ***Predictability and Dynamical Processes***
- for the European THORPEX Science Plan

**suggested to be performed in 2011/2012 **
**in conjunction with HYMEX**

-  address the triggering of waveguide disturbances by different processes and the disturbances’  subsequent downstream evolution
-  study of the downstream impacts of the waveguide disturbances over Europe, the Mediterranean, and northern Africa

## T-NAWDEX: Forecast Errors

*PV distribution “Fcst-Analysis” field. for **a 72hrs forecast to 10 Oct. 2001*
*(- based on ECMWF IFS T511 model).*

*2pvu isoline: analysis, forecast*

**	****Pertinent questions:**
**Is the difference pattern typical, and does it persist **
**	****in today’s upgraded prediction suites ? **
**Is the analysis field itself likely to be inadequate?**
**Is the difference dynamically significant **
**	****and/or operationally important?****	**
**(iv)****	****Link to ensemble predictions? **
**What is the cause of the difference ?**
**(vi)****	****How can it be rectified ? ****	****	****	****           **

- (courtesy of Huw Davies)

## “Forecast -Analysis”  fields 	for forecasts of different time-spans

-   For a specific forecast time the
-    fields have a similar spatial structure
-  Systematic difference in
-    representing  synoptic development

- FC96

- FC48

- FC72

**Marco Didone, ETH  Zürich**
**courtesy of H. Davies**

- “Forecast -Analysis”  fields 	for forecasts of different time-spans

## Heavy precipitation events 

**on the Alpine south-side**

***Distinctive mesoscale topography***

***Events of Alpine heavy precipitation***

***Downstream wave-breaking ***
***resulting in a PV-streamer***

**- 6d**

**- 12d**

**180 W**

**180 E**

***Event***

***Composite of preceeding Hovmöller trace***

**Alexia Massacand**
**Olivia Martius**
**ETH Zürich**

##    Greenland Tip Jet - Wind Lidar observation

- MODIS (Aqua) 14:55 UTC
- 24 November 2003

**   ****Greenland Tip Jet - Wind Lidar observation**

- FL200 z~6.0 km

## Horizontal Wind Speed - Wind Lidar 

**Horizontal Wind Speed - Wind Lidar **
**(One Scanner Revolution)**

**North**

**South**

## Horizontal Wind Speed -  LIDAR-ECMWF

**North**

**South**

**Horizontal Wind Speed - ******** LIDAR-ECMWF**

## 			Question (ii):	Is the analysis field itself likely 				to be inadequate ?

**PV distribution **
**on 310 K surface**

**Error > 15 m/s**

**Wind speed**

**Wind direction**

**Flight altitude & height of 310K surface**

**Aircraft **
**measurements**

**ECMWF**

**NCEP**

**Sandro Buss,ETH  Zürich**
**courtesy of H. Davies**

## Motivation for T-NAWDEX

**Errors in medium range forecasts for Europe mainly due to a small    number of 'busts',  e. g. from ET, DRW (Cardinali/Buizza)**
**There are systematic patterns of forecast errors in extratropical cyclones, e. g. the downstream side of the trough in developing cyclones should be sharper (Davies)**
**Are these deviations potentially associated with latent heat release, the most poorly understood/modelled part of the dynamics?**
**       ****Kilometer-resolution models appear to dramatically better, at least at short **
**       ****range (MAP D-PHASE), but need to be evaluated for THORPEX timescales**
**Comparison with research aircraft shows even analysis faulty**
**       ****(resolution and/or diabatic effects?), so research measurements   required**
** ****Advanced observing technologies, (air-, spaceborne platforms, active/passive remote sensing, in-situ sensors, ...) are now well-established and can be deployed**

## Scientific Objects of T-NAWDEX

**Triggering of waveguide disturbances**
**by different processes**
**Subsequent downstream evolution of **
**the disturbances,  esp. diabatic effects**
**Downstream impacts of the waveguide **
**disturbances over Europe, the **
**Mediterranean and northern Africa. e.g. **
**cooperation with HYMEX**

## THORPEX interest for HYMEX
T-NAWDEX - upstream conditions, global models, TIGGE, observing strategies
international meteorological links: Europe, North America, Africa

HYMEX interest for THORPEX
HYMEX - mesoscale and local measurements, high resolution modeling and data assimilation
SERA - end to end trial, hydrology, end users

- T-NAWDEX - upstream conditions, global models, TIGGE, observing strategies
- international meteorological links: Europe, North America, Africa
- HYMEX interest for THORPEX
- HYMEX - mesoscale and local measurements, high resolution modeling and data assimilation
- SERA - end to end trial, hydrology, end users

- THORPEX-HYMEX Links

## T-NAWDEX Planning

** ****Use HALO-Demonstration Mission HALO-THORPEX**
**      ****as nucleus for field phase**

## T-NAWDEX Planning

**(2) Planning Workshop Spring 2009**

**(a) Formulation of the Science Plan**
-        - scientific aims and questions
-        - methods to address the questions
-                (theoretical, numerical, experimental)
-        - responsible persons
**(b) Implementation Plan **
**(c) National/International Cooperation and**
**     ****fund raising**