Rossana Dragani

Using and evaluating PROMOTE

services at ECMWF

PROMOTE User Meeting

Nice, 16 March 2009

Overview of ECMWF

ECMWF is an independent international organization that provides medium and extended-range weather forecasts as well as state-of-the-art super-computing facilities for scientific research.

ECMWF is currently supported by 31 member states, mainly across Europe.

The ECMWF system is a global spectral model with a horizontal truncation resolution of T799 (~ 25 km), and 91 vertical levels from the surface up to 0.01 hPa. The assimilation is performed with a Four-Dimensional Variational (4D-Var) data assimilation scheme.

The ECMWF analyses and forecasts are widely used for a number of activities and studies. They are

used in house to study the dynamical and chemical evolution of the Earth-system,

routinely distributed to the ECMWF Member States.

In addition, the ECMWF model forecasts and analyses are routinely used to monitor observations from a number of satellites. In some cases, the ECMWF forecasts are also used as a priori information to constrain retrieval procedures of satellite instruments (e.g. ESA’s ERS2, ENVISAT).

ECMWF involvement in GMES projects

ECMWF is involved in various GMES projects. PROMOTE:

ECMWF has been receiving the PROMOTE NRT total column ozone retrieved from the SCIAMACHY instrument (on board ENVISAT) since February 2004.

These data have been assimilated in the ECMWF operational NWP since September 2004.

The Global and regional Earth-system Monitoring using Satellite and in-situ data (GEMS):

GEMS is developing comprehensive monitoring and forecasting systems for trace atmospheric constituents important for climate and air quality.

GEMS started in 2005 and will run until mid 2009.

Evaluation of PROMOTE services

Evaluation of the PROMOTE data quality: Impact on the ECMWF ozone analyses performed before the

operational use of the PROMOTE data Continuous monitoring of the PROMOTE products

www.ecmwf.int/products/forecasts/d/charts/monitoring/satellite/o3/o3knmi/

Evaluation of the PROMOTE service: Timeliness: Customers want forecasts early, therefore NWP requires

data early.

Evaluation of PROMOTE services

Evaluation of the PROMOTE data quality: Impact on the ECMWF ozone analyses performed before the

operational use of the PROMOTE data Continuous monitoring of the PROMOTE products

www.ecmwf.int/products/forecasts/d/charts/monitoring/satellite/o3/o3knmi/

Evaluation of the PROMOTE service: Timeliness: Customers want forecasts early, therefore NWP requires

data early.

Motivations for using PROMOTE data at ECMWF

The assimilation of PROMOTE TCO was seen to improve the ECMWF ozone analyses and forecasts in particular the representation of the Antarctic ozone hole.

ECMWF started the active assimilation of the PROMOTE TCO in the operational suite in September 2004.

Two pairs of assimilation experiments were run to test the impact of the PROMOTE data on the ECMWF ozone analyses:

Period 1: 24 April - 23 May 2004 Period 2: 1 August - 28 September 2004 (e-suite) CTRL: operational setup (NOAA-16 SBUV/2 ozone layers) PERT: CTRL + PROMOTE TCO

Fit to NOAA-16 SBUV PCO (Apr-May 2004):

CTRL PERT

Obs-ana=3.2 DU

Stdv=14.7 DU

Obs-ana=-10.5 DU

Stdv=14.7 DU

Ozone layer: 16 hPa - surface

Impact of the PROMOTE SCIA TCO on the ECMWF ozone analyses (Apr-May 2004)

CTRL

PERT

TOMS

Fit to ozone sondes (Apr-May 2004):

Sonde CTRL PERT

O-suite(25R2)

E-suite(25R3)

TOMS

Impact of the PROMOTE SCIA TCO on the ECMWF ozone analyses (Aug-Sep 2004)

Neumayer (lat=-71, lon=-8)

Sonde E-suite O-suite

Evaluation of PROMOTE services

Evaluation of the PROMOTE data quality: Impact on the ECMWF ozone analyses performed before the

operational use of the PROMOTE data Continuous monitoring of the PROMOTE products

www.ecmwf.int/products/forecasts/d/charts/monitoring/satellite/o3/o3knmi/

Evaluation of the PROMOTE service: Timeliness: Customers want forecasts early, therefore NWP requires

data early.

PROMOTE TCO monitoring statistics:time series (2007-2008)

The quality of PROMOTE SCIA TCO has been stable during the years. FG- and An- departures are about 2DU on global average.

www.ecmwf.int/products/forecasts/d/charts/monitoring/satellite/o3/o3knmi/

2007 2008

STD

DE

VO

BS

DEP

OBS ANFG

Comparison between PROMOTE SCIA and OMI TCO:

SCIAMACHY

OMI

2008

Evaluation of PROMOTE services

Evaluation of the PROMOTE data quality: Impact on the ECMWF ozone analyses performed before the

operational use of the PROMOTE data Continuous monitoring of the PROMOTE products

www.ecmwf.int/products/forecasts/d/charts/monitoring/satellite/o3/o3knmi/

Evaluation of the PROMOTE service: Timeliness: Customers want forecasts early, therefore NWP requires

data early.

Operability of data products to ECMWF:

Delayed cut-off

Two 12-hour (from -3h to +9h) analysis and forecast cycles at 00 and 12 UTC

Two 6-hour (from -3h to +3h) analysis and forecast cycles at 00 and 12 UTC

Early delivery

Operability of PROMOTE data to ECMWF (DCDA)

Annual Mean

2006 89.0%

2007 83.1%

2008 80.7%

2006

2007

2008

Conclusions and remarks:

Assimilation of PROMOTE SCIA TCO improved fit of ECMWF ozone column and profiles to independent data, and started operationally in Sept 2004.

The quality of TOSOMI TCO has been stable during the years. FG- and An- departures are about 2DU on global average. PROMOTE SCIA TCO is in very good agreement with OMI TCO

(independent observations) at mid and high latitudes. Smaller TCO values can be found in the TOSOMI product compared with

OMI in the Tropics. Slightly higher in the Antarctic polar vortex during spring.

The timeliness over the last three years (2006-2008) has been good, and the operability of the PROMOTE data to ECMWF higher than 80%.

However, a drop of about 8% (annual mean) was found in the operability of these data over the last three years.