TY - JOUR
T1 - Characterization of the planetary boundary layer during SAMUM-2 by means of lidar measurements
AU - Gross, Silke
AU - Gasteiger, Josef
AU - Freudenthaler, Volker
AU - Wiegner, Matthias
AU - Geiss, Alexander
AU - Schladitz, Alexander
AU - Toledano, Carlos
AU - Kandler, Konrad
AU - Tesche, Matthias
AU - Ansmann, Albert
AU - Wiedensohler, Alfred
PY - 2011/9/1
Y1 - 2011/9/1
N2 - Measurements with two Raman-depolarization lidars of the Meteorological Institute of the Ludwig-Maximilians-Universität, München, Germany, performed during SAMUM-2, were used to characterize the planetary boundary layer (PBL) over Praia, Cape Verde. A novel approach was used to determine the volume fraction of dust υd in the PBL. This approach primarily relies on accurate measurements of the linear depolarization ratio. Comparisons with independent in situ measurements showed the reliability of this approach. Based on our retrievals, two different phases could be distinguished within the measurement period of almost one month. The first (22-31 January 2008) was characterized by high aerosol optical depth (AOD) in the PBL and large υd > 95%. During the second phase, the AOD in the PBL was considerably lower and υd less than ~40%. These findings were in very good agreement with ground based in situ measurements, when ambient volume fractions are considered that were calculated from the actual measurements of the dry volume fraction. Only in cases when dust was not the dominating aerosol component (second phase), effects due to hygroscopic growth became important.
AB - Measurements with two Raman-depolarization lidars of the Meteorological Institute of the Ludwig-Maximilians-Universität, München, Germany, performed during SAMUM-2, were used to characterize the planetary boundary layer (PBL) over Praia, Cape Verde. A novel approach was used to determine the volume fraction of dust υd in the PBL. This approach primarily relies on accurate measurements of the linear depolarization ratio. Comparisons with independent in situ measurements showed the reliability of this approach. Based on our retrievals, two different phases could be distinguished within the measurement period of almost one month. The first (22-31 January 2008) was characterized by high aerosol optical depth (AOD) in the PBL and large υd > 95%. During the second phase, the AOD in the PBL was considerably lower and υd less than ~40%. These findings were in very good agreement with ground based in situ measurements, when ambient volume fractions are considered that were calculated from the actual measurements of the dry volume fraction. Only in cases when dust was not the dominating aerosol component (second phase), effects due to hygroscopic growth became important.
U2 - 10.1111/j.1600-0889.2011.00557.x
DO - 10.1111/j.1600-0889.2011.00557.x
M3 - Article
AN - SCOPUS:80051972294
SN - 0280-6509
VL - 63
SP - 695
EP - 705
JO - Tellus Series B-Chemical and Physical Meteorology
JF - Tellus Series B-Chemical and Physical Meteorology
IS - 4
ER -