data exchange meeting, dorval 26-28 may 04 met office report relocation model developments use of...

Data Exchange Meeting, Dorval 26-28 May 04

Met Office Report

Relocation Model developments Use of ATOVS AIRS data MODIS atmospheric motion winds SSM/I water vapour Sea surface temperature GPS

Roger Saunders

Presentation to N.America-Europe Data Exchange Meeting,Dorval 26-28 May 2004


Relocation

Met Office HQ relocated ~200km from Bracknell to Exeter - biggest IT move in Europe!

Operational forecasts started in Exeter Sep 03

New building completed in Dec 03

More than 70% of the staff moved to Exeter

All open plan offices (including Director!)

New director will be Dave Rogers

BracknellExeter


New Met Office Hq - Exeter


Met Office Report


Roger Saunders



Met Office NWP ModelsData Assimilation: 3DVar, FGAT, 6 hr cycle1hr 50min cut-off with 7hr update runs for next cycle

Model formulation: Exact equations of motion in 3D, non-hydrostatic effects included, semi-Langrangian scheme, hybrid-eta in height.


Global Model No major upgrades over the last year due to relocation

‘freeze’ Successfully migrated to NEC SX-6 from Cray T3E’s on

27 April 04. Satellite upgrade goes operational this week more later 4DVar planned for late summer 04 implementation,

conservative implementation but good impacts. 70L model with top above 0.1hPa planned for 2005

along with increased horizontal resolution. 16 member ensembles out to T+72 at half operational

resolution planned for 2005.


European model Domain

Current UK mesoscale

New Euro Model 20km resolution

548

320


European Model (EUROLAM)

20km grid model became operational on 23 Mar 04

Run 4 times per day out to T+48hr Data assimilation 3DVar Observation usage similar to global model Products planned to be available in late

2004 Move to 12km grid in 2005


EUROLAM Forecast


Ob type Notes Global/

Euro UK

Mesoscale Synops Surface Pressure

U,V (land)

U,V (sea)

Temperature

Relative Humidity

Visibility

Drifting buoys Aircraft AIREPS, AMDARS Sondes TEMP, PILOT, Dropsondes Satellite atmospheric motion winds

Meteosat-5/7 (IR,WV, VIS)

Meteosat-7 (IR,WV, VIS)

GOES-10/12 (IR)

GOES-9 (IR)

MODIS (Terra/Aqua)

Scatwinds Locally processed ERS scatterometer

SeaWinds (Quikscat)

ATOVS Radiances Wind profilers European and US wind profilers . AIRS Subset of radiances

SSM/I 10m windspeed

Total column water vapour

MOPS Satellite derived cloud product

Observing systems used or being assessed for use in the data assimilation system. A tick in the 3rd or 4th column indicates operational use.

Observations

used in

Global, Euro

and UK

Mesoscale

models

(May 04)


Met Office Report


Roger Saunders



Met Office NOAA Data Acquisition

Local

HRPT EARS

1a data

Global

1b data

WashingtonWest Freugh

or ExeterEUMETCAST

AAPP AAPP AAPP

METO NWP

1d data on HIRS grid

• 1a counts + housekeeping

• 1b counts + navigation + cal info

• 1c brightness temps

• 1d brightness temps on HIRS Grid

1c data to

European Met

Centres


Use of ATOVS data Global level 1b data from NESDIS Converted to level 1d (all IFOVS mapped

to HIRS) using AAPP software Level 1d radiances pre-processed with

1D-Var Level 1d radiances assimilated in 3D-Var HIRS/AMSU in Global and AMSU only in

Euro and mesoscale models Main global model run (cut-off 1:50) Update model run (cut-off ~7:00)


Use of EARS ATOVS data Receiving ATOVS 1A data from up to 8 stations Routinely compare level 1B global (from NESDIS)

with EARS level 1B (using AAPP to convert from 1A to 1B)

Comparisons of:

– Earth location

– Brightness temperatures HIRS, AMSU AMSU data show good agreement but HIRS shows

large differences due to calibration To reduce the delay in the ATOVS ‘blind’ orbits the

EUMETSAT EARS AMSU data are now being assimilated in our global forecast model


EARS data coverage

STATIONS

Black: Current

Red: Proposed future upgrade


EARS monitoring for Edmonton


EARS monitoring for Gander


EARS monitoring: NESDIS-EARS


Improved coverage for global NWP


Arrival Times of Data

• North Atlantic Region

• six-hour window

09/09/2003 09:00-15:00

window

0

10

20

30

40

50

60

70

80

90

100

09 00 10 00 11 00 12 00 13 00 14 00 15 00 16 00 17 00 18 00

Pe

rce

nta

ge

of

Ob

se

rva

tio

ns

Global 109229 obs EARS 93979 Obs

Main RunNESDIS 25%EARS 75%

Update Run both 100%

First Overpass


Experiment to assess impact of early cut-off on

forecasts Period 12 May – 4 June 2003 NOAA level 1b radiances used:

– NOAA-15 AMSU-A/AMSU-B

– NOAA-16 HIRS/AMSU-A/AMSU-B

– NOAA-17 HIRS/AMSU-A/AMSU-B

Control: All data received before 1:50 (Ops) for main run and all late ATOVS used in update run

Experiment: All data received before 1:50 + all late ATOVS received (up to 50% more data) used in main model run


All ATOVS forecast impacts

Effect of including ALL ATOVS

-7

-6

-5

-4

-3

-2

-1

0

1

2

T+24 T+48 T+72 T+96 T+120 T+24 T+48 T+72 T+24 T+24 T+48 T+72 T+24 T+24 T+48 T+72 T+96 T+120 T+24 T+48 T+72 T+24

PMSL PMSL PMSL PMSL PMSL H500 H500 H500 W250 W850 W850 W850 W250 PMSL PMSL PMSL PMSL PMSL H500 H500 H500 W250

NH NH NH NH NH NH NH NH NH TROP TROP TROP TROP SH SH SH SH SH SH SH SH SH

Parameter

RM

S F

C e

rro

r %

dif

f

Verified by Obs Verified by Analysis


Forecast impacts

N. Hem500hPa

1:50 cut-off

Improved bust?


Forecast impacts

S. Hem500hPa

1:50 cut-off

Consistent improvement


Example985 hPa low in control

975 hPa low including late ATOVS

976 hPa low in analysis


EARS forecast impactsUpper Level Windspeed (250 hPa)

5

7

9

11

13

15

17

19

21

24 48 72 96 120 144

Forecast Range (hours)

RM

S E

rro

r (m

s-1)

EARS+Global

Global


AMSU ‘precip’ imagery

increasing cloud liquid water incr. scattering

Imagery Application

Other applications outside of NWP can also exploit the timeliness of EARS data. This plot shows an example of a now-casting product that is disseminated in near real time to forecasters. The areas coloured green, red, yellow denote increasing cloud liquid water, identified using AMSUA radiances. Blue denotes the scattering signal in the AMSUB radiances, produced either by ice particles in the cloud, which can infer precipitation, or sea-ice. The product is overlaid on a coincident Meteosat IR image.


Summary of recent OSEs at the Met Office

Remove AMSU, HIRS, AMSU+HIRS radiances

Remove radiosonde temperature and humidity

Remove 1, 2, 3 x ATOVS CHAMP Radio Occultation


Percentage change in RMS fit of radiosonde Z & RH, and

ship/buoy/synop pmsl to T+6

-14

-12

-10

-8

-6

-4

-2

0

2

Per

cen

tag

e ch

ang

e in

RM

SE

Z2

50

Z5

00

Z7

00

Z8

50

No AMSU No HIRS No ATOVS No Sonde T and RH


Schematic

No AMSU and no HIRS

No AMSU so HIRS only

No HIRS AMSU onlyAMSU and HIRS

~6%~6%

~2%

~4%

~ 0%

So HIRS >> nothing. So assimilating only in cloud-free areas does improve forecasts. So AIRS should give a benefit in data sparse areas? Worth using HIRS if AMSU-A fails (as on NOAA-17)?


Percentage change in RMS fit of radiosonde Z & RH, and

ship/buoy/synop pmsl to background

-14

-12

-10

-8

-6

-4

-2

0

2

Per

cen

tag

e ch

ang

e in

RM

SE

Z2

50

Z5

00

Z7

00

Z8

50

Sh

ip &

bu

oy

pm

sl

Sy

no

pp

ms

l

3-> 0 ATOVS 3-> 1 ATOVS 3-> 2 ATOVS


Conclusions Late ATOVS missing main f/c run degrades forecasts. EUMETSAT EARS can help alleviate this. First and second AMSU are very important to NWP. Third AMSU still positive overall, but main role is

robustness. HIRS impact much less than AMSU but still an impact

on low level moisture (NB SSM/I low level moisture not used). In absence of AMSU, HIRS impact is still very significant so important for robustness.

AIRS initial impacts much larger than HIRS, smaller than sonde temperatures and much smaller than AMSU.


Met Office Report


Roger Saunders



Monitoring web page

Available via password protected pageon Met Office site.

Userid:airspagePasswd: &Graces


Change in Forecast Errors:500hPa Height at 24 hours

-0.2%

-0.6%

-1.8%

Red/green reduced errors due to AIRS


Satellite Spring UpgradeAndrew Collard, Nigel Atkinson, Brett Candy, Fiona Hilton, James

Cameron, Roger Saunders and Stephen English

AIRS radiances: cloud-free, ocean fovs only (~5% of fovs, ~3% of channels)

Aqua AMSU-A radiances EUMETSAT ATOVS Retransmission Service Radiances for

Tromso, Maspalomas and Edmonton (3 out of 8 stations). RTTOV-7 radiative transfer model replaces RTTOV-5 New bias correction scheme using 850-300hPa and 200-

50hPa thicknesses as predictors rather than AMSU channels 5 and 9.

Use of ATOVS radiances over all land areas (previously restricted to elevations < 1000m)


Met Office Report


Roger Saunders



•MODIS imagery from Terra and Aqua used to generate winds.

•IR(11m) and WV (6.7m) channels

•100 min between overlapping images.

•Time delay of 5-6 hours after valid time before winds are available.

•Still experimental. Met Office obtains them via ECMWF. Now using winds from Washington.Picture courtesy of CIMSS

MODIS polar winds


MODIS winds impact

New results using NESDIS-NCEP MODIS windsBetter results than earlier winds from CIMSS


Met Office Report


Roger Saunders



II. SSMI TPW used to validate model performance

O - B 22GHz

model‘dry’

model ‘wet’

‘normal’ regime


Met Office Report


Roger Saunders



AATSR Processing in real time


(A)ATSR SSTanomalies

Climate Model SST anomalies

AATSR

ATSR-2ATSRERS-2 gyrofailure


Met Office Report


Roger Saunders



GPS Stations for TCWV

Current GPS network shown over Europe

TCWV data put on GTS in real time

Plans to assimilate in Euro model


Ozonesondes from Lerwick The Met Office started launching

weekly ozonesonde ascents from Lerwick in Feb 04

Normally ~11Z on a Wednesday Ascents put on GTS in real time in

WMO BUFR format Data also sent to NILU To ensure continuity an email/letter

of interest to Met Office would help


Future PlansShort term Assimilation of MODIS winds More ATOVS in Mesoscale/EARS in EUROLAM Day-2 AIRS assimilation (Cloud cleared, recon rads…) GPS-RO trials using CHAMP (initial results

encouraging)

Longer term: Assimilation of more data over land Assimilation of cloudy radiances Assimilation of precip inferred from microwave

radiances Use of METOP data


Advanced sounder data volumes

1

10

100

1000

10000

100000

Total received (2003) ATOVS 3X received AIRS received IASI compressed IASI uncompressed

Mb

yte

s/d

ay

Current plans

data exchange meeting, dorval 26-28 may 04 met office report relocation model developments use of...

Documents