Multiwavelength aerosol lidar and vertical-wind lidar observations during COPS

Dietrich Althausen, Detlef Müller, Ronny Engelmann, Matthias Tesche, Patric Seifert, Julia Fruntke, Christina Herold, Luise Hentschel, (Albert Ansmann)

Leibniz Institute for Tropospheric Research, Leipzig, Germany

Aerosol and vertical–velocity profiling and cloud glaciation observations during COPSApplicant: Albert Ansmann

Contribution to ACM and SPP 1167 (2 year period)

• Aerosol characterization • Obtaining geometrical, optical, and microphysical properties of aerosols and clouds Derivation of microphysical properties such as aerosol number

concentration

• Vertical Wind in the upper PBL (at cloud base)

• Studies of heterogeneous ice formation • Investigating the effect of aerosol particles and meteorological conditions on cloud glaciation Many Saharan dust cases and forest fire cases observed

DF

G p

ropo

sal

3 months of data, 400-500 hours

Backscatter Extinction lidar-Ratio Temperature Humditiy profiling Apparatus

Wind Lidar

0

1000

2000

3000

4000

0 2 4 6 8 10

355 nm 400 nm 532 nm 710 nm 800 nm 1064 nm

BACKSC. COEF. (Mm-1 sr-1)

HE

IGH

T (

m)

0 200 400 600 800

25 MARCH 1999: Optical Parameters mean of 3600 s, 1330 - 1500 UTC

EXTINCTION COEF. (Mm-1)

355 nm 532 nm

INDOEX,Maldives1999-2000

SAMUM I, Morocco, May-Jun 2006COPS, Black F., Jun-Aug 2007SAMUM II, Cape Verde, Jan/Feb+May/Jun 2008

6 x beta 2 x sigma

Inversion algorithm

Input: – 6 backscatter coefficients – 2 extinction coefficients

Output:– volume size distribution– effective radius– total volume concentration– total surface-area concentration– mean complex refractive index– single-scattering albedo

COPS: β(532nm) ~ n (particle number conc.)

VALIDATION OF INVERSION RESULTS WITH AIRBORNE IN-SITU MEASUREMENTS

LACE 98: Biomass Burning From NW CanadaMeasurement : 9 August 1998

3500-4000 m 3400-3900 m inversion in-situ

IfT IMP (r > 50 nm)

eff. radius ( m)

v ( m /cm ) 3 3

s ( m /cm ) 2 3

n (1/cm ) 3

real part

imag.

single-scat.albedo (532nm)

part

0.27

13

142

295

1 .62

0 .047

0 .81

0 .04

2

7

64

0 .08

0 .013

0 .03

0.24

11

136

506

1 .66

0 .79

0 .053

0 .01

1

5

131

0 .02

0 .01

0.004

0 .25 0 .07

8 5

95 55

271 74

(1.56)

(0.07)

0.79 0 .02

9 August 1998, 2200-2400 U TC

COPS: we may only get the order of magnitude of the particle number conc. (100 cm-3, 1000 cm-3, 10000 cm-3)

DLR Falcon

Aerosol type: finger prints

Aerosol type Lidar ratio (sr) Depol. ratio (%) Maritime S355=S532 (low) <5% (low)

Urban S355>=S532 (high) <5% (low) Forest fire smoke S355<S532 (high) <10-15% (med) Desert Dust S355>=S532 (high) 25-35% (high)

355 nm versus 532 nm

COPS: Some measurement examples

PBL+CU

Vertical wind

P B L d e v e l o p m e n t

in terms of vertical wind

profile of horiz. wind speed and direction

Deep cumulus tower

Spectacular event

Heterogenous ice formation

melting layer

uncalibrated depol. ratio (710nm)

AC

ICE

terminal velocities

CI

Bertha + Wili

Topic 1 Topic 2PBL heterog. ice form.

Influence of Saharan dust and biomass burning smoke on cloud glaciationover the northern tropical Atlantic Ocean (Cape Verde) during SAMUM II

Published February 2008

SAMUM II: 15 Jan – 14 Feb 2008, Praia, Cabo Verde (15oN, 23.5oW)

Our work on heterogenous ice formation

…upcoming

Next future (beginning in March 2008):

Diploma student working on WiLi data (wind fields)

Diploma student working on Raman lidar data(water vapor and temperature)

BERTHA, Heselbach, 532nm backscatter signal

PBL, sunny day dust

BERTHA, water vapor Raman lidar, Heselbach

SONDE

LIDAR, 20 min, 60m smoothing LIDAR, 1 min, 240 m smoothing

LIDAR

LIDAR

532 nm backscatter signal

g/kg

COPS:

Bertha(Raman lidar)

water vapor

nighttime,

1 min res.,60 m height res.