ANNUAL VARIABILITY OF ATMOSPHERIC BOUNDARY LAYER IN WARSAW Iwona S. Stachlewska1, Szymon Migacz2, Artur Szkop1, Anna J. Zielinska1, Michal Piadlowski1,
Pawel L. Swaczyna2, Krzysztof Markowicz1, Szymon Malinowski1 and Anna Gorska1
1Institute of Geophysics, Faculty of Physics, University of Warsaw, Pasteura 7, 02-093 Warsaw, Poland
2College of Inter-Faculty Individual Studies in Mathematics and Natural Sciences, University of Warsaw, Zwirki I, Wigury 93, 02-089 Warsaw, Poland
Four years of quasi-continuous CHM 15K ceilometer observations above Warsaw, resulted in large statistics of boundary layer height, clouds, fog, and precipitation cases, obtained by filtering and smoothing algorithms developed ourselves. Presented here annual cycles of boundary layer depth are the first of such results obtained using an active remote sensor in Poland.
S8P-02
CHARACTERIZATION OF PBL HEIGHT AND STRUCTURE BY RAMAN LIDAR:
SELECTED CASE STUDIES FROM THE CONVECTIVE AND OROGRAPHICALLY-INDUCED PRECIPITATION STUDY
Donato Summa, Paolo Di Girolamo, Dario Stelitano
DIFA, Univ. della Basilicata, Viale dell'Ateneo Lucano n. 10, 85100 Potenza, Italy
The planetary boundary layer includes the portion of the atmosphere which is directly influenced by the presence of the Earth's surface. Aerosol particles trapped within the PBL can be used as tracers to study boundary-layer vertical structure and time variability. As a result of this, elastic backscatter signals collected by lidar systems can be used to determine the height and the internal structure of the PBL. Our analysis considers a method based on the first order derivative of the range-corrected elastic signal, which is a modified version of the method defined by Seibert and Sicard. The analysis is focused on selected case studies collected by the Raman lidar system BASIL during the Convective and Orographically-induced Precipitation Study, held in Southern Germany and Eastern France in the period June-August 2007. Estimates of the PBL height and structure for specific case studies obtained from the above mentioned approach are compared with simultaneous estimates obtained from potential temperature profiles determined from the radiosondes launched simultaneously to lidar operation. Additional estimates of the boundary layer height and structure are obtained from lidar temperature signals. Preliminary results from these comparisons are illustrated and discussed in this paper.
S8P-03
EVOLUTION OF THE ATMOSPHERIC BOUNDARY LAYER: LIDAR OBSERVATIONS AND MODELING
Edson R. Marciotto1, Walter M. Nakaema2, Eduardo Landulfo2
1Division of Atmospheric Sciences, Instituto de Aeronáutica e Espaço – IAE, Praça Marechal do Ar Eduardo Gomes, 50, Vila das Acácias, São José dos Campos, SP, Brazil
2Center for Lasers and Applications (CLA), Instituto de Pesquisas Energéticas e Nucleares – IPEN, Av. Prof. Lineu Prestes 2242, Cidade Universitária, São Paulo, SP, Brazil
A single-wavelength elastic backscatter LIDAR system localized at the Center for Lasers and Applications (CLA) of the Instituto de Pesquisas Energéticas e Nucleares (IPEN) in São Paulo (Brazil) was used to monitoring the development of the Atmospheric Boundary Layer (ABL) during the periods of March, April and June, 2007. Using a simple model that describes the dynamics of the inversion above a convective layer following Tennekes, we estimate the surface sensible heat flux parameters and time evolution.
S8P-04
ATMOSPHERIC BOUNDARY LAYER HEIGHT DETERMINATION:
COMPARISON OF DIFFERENT METHODS AS APPLIED TO LIDAR MEASUREMENTS Daniel Toledo1, Carmen Córdoba-Jabonero1, Emilio Cuevas2, Manuel Gil1
1Instituto Nacional de Técnica Aeroespacial (INTA), Atmospheric Research and Instrumentation Branch, Torrejón de Ardoz, Madrid, Spain
2Agencia Estatal de Meteorología (AEMET), Atmospheric Research Centre of Izaña (CIAI), Sta. Cruz de Tenerife, Spain
The Atmospheric Boundary Layer (ABL) height is calculated from lidar data by using different methods.
These methods represent different mathematical approaches with particular application to lidar measurements. Among them, there are: the Gradient Method (GM), the Logarithm Gradient Method (LGM), the Inflection Point Method (IPM), the Wavelet Covariance Transform (WCT), and the Centroid/Variance Method (VM), in addition to the Cluster Analysis (CA), the first time this statistical method has been applied to calculate the ABL height by lidar measurements.
S8P-05
LIDAR OBSERVATIONS OF FINE-SCALE ATMOSPHERIC GRAVITY WAVES IN THE NOCTURNAL BOUNDARY LAYER ABOVE AN ORCHARD CANOPY
Elizabeth R. Jachens and Shane D. Mayor
Departments of Geosciences and Physics California State University Chico, 400 West First St., Chico, CA 95929, USA
Fifty-two episodes of micro-meteorological gravity wave activity were identified in data collected with the Raman shifted Eye-safe Aerosol Lidar (REAL) near Dixon, California, during a nearly continuous 3-month period of observation. The waves, with wavelengths ranging from 40 m to100 m, appear in horizontal cross-sectional elastic backscatter images of the atmospheric roughness sub-layer between 10 m and 30 m AGL. All of the episodes occur at night when the atmosphere tends toward stabil ity. Time-series data from in situ sensors mounted to a tower that intersected the lidar scans at 1.6 km range reveal oscillations in all three wind velocity components and in some cases the temperature and relative humidity traces. We hypothesize that the lidar can reveal these waves because of the existence of vertical gradients of aerosol backscatter and the oscillating vertical component of air motion in the wave train that displace the backscatter gradients vertically.
INVESTIGATION OF VERTICAL AEROSOL DISTRIBUTIONS IN THE VICINITY OF IOWA CITY
Tingyao He1, Samo Stanič1, William Eichinger2, Brad Barnhart2
1Center for Atmospheric Research, University of Nova Gorica, 5000 Nova Gorica, Slovenia
2IIHR-Hydroscience & Engineering, University of Iowa, Iowa City, IA, USA
We present the results of the measurement of aerosol loading within Iowa City, USA and along the highway Interstate 80 between Iowa City and Davenport conducted on 9 and 10 August 2011 using a vehicle-mounted elastic lidar. Vertical extinction profiles were obtained from the lidar return signals using the Klett method. The results show that on 9 August 2011 aerosol plume from local pollution sources within Iowa City remained mainly less 200 m above the ground with extinction coefficient of about 0.16 km−1. We observed that both maximum height and extinction coefficient of the aerosol layer gradually decreased when moving out from urban to suburban areas. Measurements along the highway Interstate 80 showed that aerosol loading was strongly related to the entries and the smallest concentration was found in the vicinity of the Mississippi River.
S8P-07
OBSERVATION IN THE TROPOSPHERE OVER MOUNTAIN VALLEY BY CEILOMETER, SUN PHOTOMETER AND LIDARS
Nikolay Kolev1, Ivan Grigorov1, Tsvetina Evgenieva1, Atanaska Deleva1 Evgeni Donev2, Danko Ivanov2, Doyno Petkov 3
1Institute of Electronics, Bulgarian Academy of Sciences, 72, Tsarigradsko shosse Blvd., Sofia 1784, Bulgaria
2Department of Meteorology and Geophysics, Faculty of Physics, Sofia University “St. Kliment Ohridsky”, Sofia, Bulgaria
3Solar-Terrestrial Influences Laboratory, Bulgarian Academy of Sciences, Sofia, Bulgaria
The atmospheric boundary layer (ABL) over the land is directly influenced the earth’s surface and rapidly responds to the diurnal cycle of solar radiation. Daytime solar radiation heats the surface, initiating thermal instability or convection. Under clear skies the daytime ABL, the so-called convective boundary layer, can extend up to a height of 1-2 km and more. Strong turbulence homogenizes the ABL conservative properties as temperature, humidity and trace species like aerosols. The evolution of the ABL interacts directly with aerosols modifying radiative fluxes by scattering and absorption of solar radiation.
The height of the ABL determines the volume where air pollutants are spread and are subject to physico-chemical transformations over urban area. Most of aerosol resides within the first 2-3 km (by height) of the atmosphere. In the paper we present results from combined campaign measurements with two lidars, ceilometer and two meteorological stations. HYSPLIT back trajectory model data are also used.
S8P-08
DEVELOPMENT OF BACKSCATTERED LIDAR SYSTEM AND FIRST TROPOSPHERIC MEASUREMENTS AT CONCEPCIÓN, CHILE (36° S, 73°W)
Montilla-Rosero Elena1,2, Silva Antonieta 1,2, Jiménez Chrostofer 1,2, Saavedra Carlos 1,2, Hernández Ronaldo1,2
1Center for Optics and Photonics, University of Concepción, Esteban Iturra s/n, Concepción, Chile
2Department of Physics, University of Concepción, Esteban Iturra s/n, Concepción, Chile
A new lidar station was setup up at Concepcion, Chile (36º 47´S, 73º7’W, 170 amsl) and provides the first regular measurements of tropospheric aerosol backscatter profiles in Chile. The system has been developed to study the evolution of the atmospheric boundary layer (ABL) and vertical profiles of aerosol optical properties over the city. The system is located in the Transportable Integrated Geodetic Observatory (TIGO) of the University of Concepción and it has been set up on transportable facility to carry up field measurement campaigns at any place across the country. The first experimental profiles of the aerosol backscatter have been acquired during the second half of summer 2012 (southern hemisphere).
In this work, the first data about the atmospheric boundary layer (ABL) height are retrieved from Lidar measurements using two different techniques: the logarithm gradient method and the inflection point method.
S8P-09
DETECTION OF THE BOUNDARY LAYER AND ENTRAINMENT ZONE BY LIDAR Camelia Talianu, Doina Nicolae, Emil Carstea, Livio Belegante
National Institute of R&D for Optoelectronics, 409 Atomistilor Str., Magurele, Romania
The boundary layer (BL) and the entrainment zone (EZ) can be observed by a variety of methods, but quantitative measurement of their height/thickness often gives different results, depending on the definition and parameters used. The purpose of this study is to assess the capability of backscatter lidars to provide BL height and entrainment zone thickness by comparison with methods based on meteorological criteria. We used modeled and measured (microwave radiometer) meteorological data, as well as measured (backscatter lidar) optical data. The analysis was performed on 102 datasets, spread over all seasons and 3 years (2009-2011). We found good agreement in BL height and only partial agreement in EZ thickness. A better agreement was found in case of lidar and microwave radiometer, which demonstrate that both BL and EZ are highly variable in time and space. Good correlation obtained between remote sensors (0.97 for BL height, and 0.76 for EZ thickness) suggests that both instruments are well suited for BL field experiments, and algorithms are stable enough.