TReSS (Transportable Remote Sensing

Station) in Tamanrasset

• Overview of TReSS • Status of implementation on April 1st 2006• Operations in the framework of the AMMA lidar network

• TReSS team:– Cyrille Flamant (IPSL/SA, CNRS, Paris, France) – Juan Cuesta (IPSL/LMD, CNRS, Palaiseau, France)– Pierre Flamant (IPSL/LMD, Palaiseau, France)– Dimitri Edouart (IPSL/LMD, Palaiseau, France)– Claude Loth (IPSL/LMD, Palaiseau, France)– Jacques Pelon (IPSL/SA, CNRS, Paris, France)

• Support teams: gratefully acknowledged !– Algéria: OMN in Algers and Tamanrasset– France: L. Gomes (CNRM) & K. Desboeufs (LISA) & M. Legrand

(LOA)

TReSS science objectives and teamsMain objective: Improved knowledge of heat low dynamics and

aerosol radiative properties in the heat low region

Ancillary objective: CAL/VAL for CALIPSO and the A-Train

Funded by API & CNES & IPSL

What is TReSS?TReSS is an autonomous and high-performance system designed toobserve radiative and structural properties of clouds and aerosol layers,as well as atmospheric boudary layer dynamics.

The standard payload is made of the following instruments:1) a multi-wavelength elastic backscatter Mini-Lidar operating at 532 and1064 nm (with diverse polarization capability at 532 nm),2) a sun-photometer,3) an IR radiometer,3) a full sky visible channel web-type camera.

For the AMMA SOP period, the platform capability will be enhanced with:• an Optical Depth Sensor (for daytime and nighttime measurements),• a CLIMAT radiometer• a sonic anemometer• a GRIMM for size distribution measurements• a nephelometer operating at 880 nm• filters for chemical speciation (in collaboration with LISA)

The above instrumentation will also be enhanced by the measurements conductedroutinely by the Météo Algérienne: balloon soundings (x4 during the SOP), surfaceMeteorological measurements, radiative measurements, ozone integrated column

TReSS measurements• Aerosol and molecular extinction coefficient profiles (30 m verticalresolution, 10 s temporal resolution) km-1

• Aerosol layers optical and geometrical depths unitless and m• ABL depth m• Thick cloud base altitude m• Thin cloud optical and geometrical depths (15 m res) unitless and m• Total aerosol optical depth at 8 wavelengths from the sunphotometer(340, 380, 440, 500, 670, 870, 936 and 1020 nm) and 2 wavelengths(330-400 and 780-1100 nm) for the ODS unitless• Integrated water vapor content kg m-2

• IR irradiance in the 8-13µm, 11.5-12.5 µm, 10.5-11.5 µm, 8.2-9.2 µmand 9.5-11.5 µm ranges W m-2

• Full-sky visible images (10 s temporal resolution)• Surface sensible heat flux (5 min. temporal resolution) W m-2

• Aerosol size distribution between 0.1 and 5 µm (3-6 hourly) µm3 µm-2

• Aerosol phase fonction in the 45°-90° ranges (5 min. res) sr-1

Schedule of AMMA SOP operation

26/06/06 – 02/07/06

03/07/06 – 09/07/06

10/07/06 – 16/07/06

17/07/06 – 23/07/06

24/07/06 – 30/07/06

31/07/06 – 06/08/06

07/08/06 – 13/08/06

14/08/06 – 20/08/06

21/08/06 – 27/08/06

28/08/06 – 03/09/06

04/09/06 – 10/09/06

16/07/0616/07/06

08/07/2006 30/07/200622/07/2006 13/08/2006

05/08/2006 03/09/2006

WEEK30/01/06 – 05/02/06

06/02/06 – 12/02/06

13/02/06 – 19/02/06

15/05/06 – 21/05/06

22/05/06 – 28/05/06

29/05/06 – 04/06/06

05/06/06 – 11/06/06

12/06/06 – 18/06/06

19/06/06 – 25/06/06

TReSS - TamanrassetJ. Cuesta 04/02/06 19/02/06 27/05/06D. Edouart 04/02/06 19/02/06 27/05/06F. MarnasF. LapougeF. Gibert

SOP 0 (almost)Installation & first measurements

SOP 2a1

SOP 2a2

SOP 1a

Status of implementation

• The multi-wavelength backscatter Mini-Lidar seriously damaged during transportation between Algers and Tamanrasset

New laser and new telescope are needed!!Replacement scheduled for SOP 1a

• Sun-photometer operational since 16/02/06 (data transmitted to AERONET and available on the web)

• CLIMAT radiometer operational since 17/02/06 (data transmitted to M. Legrand at LOA via internet)

• Sonic anemometer operational since 18/02/06 (installed on 10 m mast)

• Size distribution measurements operational since 18/02/06

Failure

Operational

Status of implementation

• Full sky visible channel web-type camera

• IR radiometer

• Nephelometer

Tested / will be running during lidar operations

• Optical Depth Sensor (for daytime and nighttime measurements)

• Filters for chemical speciation

To be installed / tested (before SOP 1a)

TReSS-lidar measurements in the framework of the lidar

network

Important issues associated with networking: • to document the diurnal cycle of relevant variables in the heat lowregion (ABL structure, aerosol content and properties, etc..),• to document diurnal cycle of relevant variables NORTH and SOUTHof the ITF,• to document the diurnal cycle of relevant variables before and afterthe passage of MCSs (not really relevant for TReSS, but….),• validation CALIPSO products over the Sahara, which will in turn beused to analyze the mesoscale/large scale variability of the PBL/SALand aerosol properties.

IOPs: • Day J: continuous• Days J-1 & J+1: continuous ??

Outside IOPs:• 4 h around 12 z (flexible)