AMMA-UKAtmospheric profiling

Status of planning, January 2006

• Radiosondes• Sodars• Tethersonde

Radiosondes

• Managed with AMMA-EU• 208 sondes bought from CSIP @ 80

GBP and shipped to Tamale/Abuja.• 531 sondes sent for Agadez for 0000

UTC soundings (no gas / balloons).• Reserve budget available for Tessalit

(proposing to use a local consultant). • Thinking about high resolution strategy

for northern stations …

Northern Quadrilateral – need to evaluate consequences – deploy EAMAC station

AMMA Priority 1 stations ; ASECNA:AMMA Priority 2 stations ; ASECNA:Temporary stations (planned)Other stations ; ASECNA …………..:GPS stations ; UHF VHF stationsAMMA mesoscales sitesShips

SOP

Djougou

Dakar

SalNouakchott

Conakry

Man

Tambacounda

Nouadhibou

Tindouf

Abidjan

Bamako

Tessalit

Tamanrasset

In Salah

Agadez

Tombouctou

Niamey KhartoumTahoua

Sarh

N’DjamenaOuagadougou

Ouesso

Bangui

Adis-Abeba

Ngaoundere

Pointe Noire

Libreville

Tamale

Cotonou

AbujaParakou

SOP1&2

SOP3

Sodar network and tethered balloon(s) (for Niamey)

Background:One of the objectives of these flights is to provide measurements ofatmospheric response to surface heterogeneity, notably from recentrainfall. The following figures provide an indication of what surfacemoisture heterogeneity might be sampled at this time of year fromflights in this region.

Data used:• Meteosat 7 ~4.5km pixel resolution TIR and VIS, June 6 –September 30 2000 (only June 7-15 shown)• Raw TIR data to locate cold cloud in previous 24 hours• Daytime cloud-screened TIR to locate surface temperatureanomalies (often associated with surface soil moisture from recent rain)

Interpretation of figures:Antecedent cold cloud maps (left hand side) provide an indication ofwhere convective systems have passed, but cannot accurately locatewhere surface rainfall occurred, or indeed whether it rained at all.In sparsely-vegetated regions on the other hand, recent rainfallproduces a strong decrease in surface temperature.In cloud-free zones, interpretation of maps of brightness temperature anomalies (compared to a longer-term mean diurnal cycle calculated,in this case, over 15 days) can provide accurate locations of stormtracks. The surface is likely to be wet if it:• Has low brightness temperature• Is coincident with cold cloud feature in recent 24-48 hours• Has a well-defined patch edge• Has geometry associated with “typical” storms e.g. oriented NE-SW Flight planning during the SOPCEH hope to set up an operational system for the SOP based onnear-real-time satellite data which can assist flight planning duringthe morning of the flights. This will be based on cloud-screenedMeteosat Second Generation data, and other sensors if available.Using this technique, we hope to be able to accurately locatewet/dry surface patches from recent rainfall, and hence providesuitable cases of heterogeneity for the aircraft to sample. Weanticipate improvements in the cloud-screening using MSG whichwill hopefully make the Niamey region less obscure (the currentalgorithm is very conservative).

Quick Look at Meteosat Data from June 2000 (Chris Taylor, CEH)

Chris Taylor, CEH Wallingford

Surface temperature (1200 UTC) and boundary layer TKE in the afternoon (around 1500 UTC)

The observed monsoon (v-wind) is related to recent rainfall.

Filtered v-wind (Richard Ellis, CEH)Filtered v-wind (Richard Ellis, CEH)

The monsoon flow is active at night and in the morning.

Typical soil moisture anomaly

4 Sodars

N

100 km

3 AMMA-UK sodars (U. Leeds) combined with one 3 AMMA-UK sodars (U. Leeds) combined with one identical system from FZK Karlsruhe in the Niamey region.identical system from FZK Karlsruhe in the Niamey region.

Backscatter and windsBackscatter and winds

Sea breeze (UK)Sea breeze (UK)

Wind directionWind direction

Tethersonde

• The turbulence sonde is under development

• We propose to take a convectional PTU + wind sonde also

• ‘Skydoc’ balloon should fly in all wind conditions outside Cb conditions

• Propose 4+ hour flights associated (and not) with BAe146 activity in the area (3-4 person team).

Week 29/5 5/6 12/6 19/6 26/6

3/7

10/7 17/7 24/7 31/7 7/8 14/8 21/8 28/8 4/9 11/9

SOP # SOP1 SOP2

Dates 1 June – 30 June 1 July – 15 Sept

Aircraft SOP 1-a SOP 2-a1 SOP 2-a2 SOP 2-a3

Dates 1 – 15 June 1 – 15 July 17 July – 25 August 1 – 15 Sept

BAe146 17 July – 21 August 22 – 28/8

ATR 1 – 15 June 1 – 15 July 25 July – 25 August

F-F20 1 – 15 June 1 – 15 July 25 July – 25 August 1 – 15 Sept

D-F20 1 – 15 July 1 – 20 August

Geoph. 1 – 20 August

Sodars June 1 – 21 August

Tether-sonde

17 July – 21 August

Deployment periods in SOP1 and SOP2Deployment periods in SOP1 and SOP2