OWP: Radiosondes and profilers

Doug Parker,CEH Wallingford, 21 January

2005

Why are the radiosondes needed?• Data assimilation

– Detailed (sustainable) analysis of weather and climate– Data impact studies

Is the existing network sufficient to analyse the atmosphere ?

Adrian Tompkins

(ECMWF)

ECMWF data impacts(Tompkins et al 2005)

• All data are about equally useful, but– Radiosondes are most important at lower

levels (below ~ 600 hPa ~ 16,000 ft)– Radiosonde thermodynamics are more

important than all wind data

Why are the radiosondes needed? SOP objectives for radiosonde data• High resolution analysis of weather

systems– Coordinated with radar, aircraft …– Diurnal cycle high frequency

• Water and energy budgets

• Assimilation into regional models - Regional NWP

• Security of aviation

‘AMMA’ network ASECNANew stations

Non-ASECNANot reporting

Quadrilaterals - fluxes

Sounding frequencies on these networks

• EOP/LOP: As a minimum:– March 2005 – October 2007: 1 per day– March 2006 – October 2006: 1 more per day– Total: 1220 per station (~ 20,000 soundings)– Extra: 6350 sondes contributed by AMMA-IP

• SOP: Depends on operations –– Could be 8 per day;– Could make use of descent data– Plan for 4600 additional soundings

AMMA RS projects:• AMMA-EU 2 MEu (includes Infrastructure)• France - limited money for upgrade and about

1000 soundings (EOP)• UK - about 880 soundings (EOP/SOP).• US - seeks funds for

– SOP soundings (about 1000)– 2 ISS deployments (SOP)– Conakry + sondes (EOP/SOP)

• These are relatively small-scale!

Other AMMA RS activities:

• Monitoring of data transmission and receipt (data collectors ECMWF)

• Monitoring PILOT network

• Archiving high resolution data

• Strategy and implementation for long-term support

AMMA Radiosonde Group

• Formed mid-2003

• Objectives:– to formulate strategy for radiosonde

deployment and– to assist in liaison between data providers and

data users

http://www.env.leeds.ac.uk/~doug/AMMAsondes/

AMMA-UK radiosondes

• Budget incorporated in ‘Global’ AMMA RS budget

• Purchasing through ASECNA – lower prices

• We are buying priorities in the deployment!– To support the northern region (one station at

higher frequency)– To support the BAe146

Tethered balloon system

• Carries a turbulence sonde

• Ceiling ~ 2 km

• To be deployed June to September 2006

3 sodars• To be deployed in one of the surface flux

mesosites (probably around Niamey)• June to September 2006

Sodar specifications

• Thickness of layer 10 - 250 m • Lowest measurement height 20 m • Maximum range 500 - 1000 m • Averaging time 1 min to 60 min (typically 10 min)• Accuracy of Horizontal Wind speed 0.1 - 0.3 m/s • Accuracy of vertical Wind speed 0.03 - 0.1 m/s • Accuracy of wind Direction 2 - 3° • Measurement range horizontal - 50 m/s to +50 m/s • Measurement range vertical -10 m/s to +10 m/s • Operational temperature range -35 to 50 °C