Closure study on optical and microphysical properties of a mixed urban and Arctic haze air mass observed with Raman lidar and Sun photometer

Abstract. An advanced multiwavelength polarization Raman lidar was operated aboard the icebreaker Polarstern during the MOSAiC (Multidisciplinary drifting Observatory for the Study of Arctic Climate) expedition to continuously monitor aerosol and cloud layers in the central Arctic up to 30 km height. The expedition lasted from September 2019 to October 2020 and measurements were mostly taken between 85 and 88.5∘ N. The lidar was integrated into a complex remote-sensing infrastructure aboard the Polarstern. In this article, novel lidar techniques, innovative concepts to study aerosol–cloud interaction in the Arctic, and unique MOSAiC findings will be presented. The highlight of the lidar measurements was the detection of a 10 km deep wildfire smoke layer over the North Pole region between 7–8 km and 17–18 km height with an aerosol optical thickness (AOT) at 532 nm of around 0.1 (in October–November 2019) and 0.05 from December to March. The dual-wavelength Raman lidar technique allowed us to unambiguously identify smoke as the dominating aerosol type in the aerosol layer in the upper troposphere and lower stratosphere (UTLS). An additional contribution to the 532 nm AOT by volcanic sulfate aerosol (Raikoke eruption) was estimated to always be lower than 15 %. The optical and microphysical properties of the UTLS smoke layer are presented in an accompanying paper (Ohneiser et al., 2021). This smoke event offered the unique opportunity to study the influence of organic aerosol particles (serving as ice-nucleating particles, INPs) on cirrus formation in the upper troposphere. An example of a closure study is presented to explain our concept of investigating aerosol–cloud interaction in this field. The smoke particles were obviously able to control the evolution of the cirrus system and caused low ice crystal number concentration. After the discussion of two typical Arctic haze events, we present a case study of the evolution of a long-lasting mixed-phase cloud layer embedded in Arctic haze in the free troposphere. The recently introduced dual-field-of-view polarization lidar technique was applied, for the first time, to mixed-phase cloud observations in order to determine the microphysical properties of the water droplets. The mixed-phase cloud closure experiment (based on combined lidar and radar observations) indicated that the observed aerosol levels controlled the number concentrations of nucleated droplets and ice crystals.

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Determination of stratospheric aerosol microphysical properties from independent extinction and backscattering measurements with a Raman lidar

Applied Optics ◽

10.1364/ao.34.008315 ◽

1995 ◽

Vol 34 (36) ◽

pp. 8315 ◽

Cited By ~ 51

Author(s):

Ulla Wandinger ◽

Albert Ansmann ◽

Jens Reichardt ◽

Terry Deshler

Keyword(s):

Stratospheric Aerosol ◽

Raman Lidar ◽

Microphysical Properties

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Raman Lidar and Sun Photometer Measurements of Aerosols and Water Vapor

Advances in Atmospheric Remote Sensing with Lidar ◽

10.1007/978-3-642-60612-0_6 ◽

1997 ◽

pp. 23-26 ◽

Cited By ~ 1

Author(s):

R. A. Ferrare ◽

S. H. Melfi ◽

D. Whiteman ◽

K. D. Evans ◽

G. Schwemmer ◽

...

Keyword(s):

Water Vapor ◽

Raman Lidar ◽

Sun Photometer

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CADEX and beyond: Installation of a new PollyXT site in Dushanbe

E3S Web of Conferences ◽

10.1051/e3sconf/20199902010 ◽

2019 ◽

Vol 99 ◽

pp. 02010

Author(s):

Ronny Engelmann ◽

Julian Hofer ◽

Abduvosit N. Makhmudov ◽

Holger Baars ◽

Karsten Hanbuch ◽

...

Keyword(s):

Asian Dust ◽

Raman Lidar ◽

Technical Institute ◽

Lidar System ◽

Microphysical Properties ◽

Source Regions ◽

Central Asian ◽

Lidar Measurements ◽

Academy Of Sciences

During the 18-month Central Asian Dust Experiment we conducted continuous lidar measurements at the Physical Technical Institute of the Academy of Sciences of Tajikistan in Dushanbe between 2015 and 2016. Mineral dust plumes from various source regions have been observed and characterized in terms of their occurrence, and their optical and microphysical properties with the Raman lidar PollyXT. Currently a new container-based lidar system is constructed which will be installed for continuous long-term measurements in Dushanbe.

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Mineral dust observed with AERONET Sun photometer, Raman lidar, and in situ instruments during SAMUM 2006: Shape-dependent particle properties

Journal of Geophysical Research Atmospheres ◽

10.1029/2009jd012523 ◽

2010 ◽

Vol 115 (D11) ◽

Cited By ~ 30

Author(s):

D. Müller ◽

A. Ansmann ◽

V. Freudenthaler ◽

K. Kandler ◽

C. Toledano ◽

...

Keyword(s):

Mineral Dust ◽

Raman Lidar ◽

Particle Properties ◽

Sun Photometer

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Multi-wavelength Raman lidar, sunphotometric and aircraft measurements in combination with inversion models for the estimation of the aerosol optical and physico-chemical properties over Athens, Greece

Atmospheric Measurement Techniques Discussions ◽

10.5194/amtd-5-589-2012 ◽

2012 ◽

Vol 5 (1) ◽

pp. 589-625

Author(s):

R. E. Mamouri ◽

A. Papayannis ◽

V. Amiridis ◽

D. Müller ◽

P. Kokkalis ◽

...

Keyword(s):

Water Vapor ◽

Chemical Properties ◽

Urban Site ◽

Aircraft Measurements ◽

Raman Lidar ◽

Lidar System ◽

Aerosol Composition ◽

Microphysical Properties ◽

Multi Wavelength

Abstract. A novel procedure has been developed to retrieve, simultaneously, the optical, microphysical and chemical properties of tropospheric aerosols with a multi-wavelength Raman lidar system in the troposphere over an urban site (Athens, Greece: 37.9° N, 23.6° E, 200 m a.s.l.) using data obtained during the European Space Agency (ESA) THERMOPOLIS project which took place between 15–31 July 2009 over the Greater Athens Area (GAA). We selected to apply our procedure for a case study of intense aerosol layers occurred on 20–21 July 2009. The National Technical University of Athens (NTUA) EOLE 6-wavelength Raman lidar system has been used to provide the vertical profiles of the optical properties of aerosols (extinction and backscatter coefficients, lidar ratio) and the water vapor mixing ratio. An inversion algorithm was used to derive the mean aerosol microphysical properties (mean effective radius – reff), single-scattering albedo (ω) and mean complex refractive index (m) at selected heights in the 2–3 km height region. We found that reff was 0.3–0.4 μm, ω at 532 nm ranged from 0.63 to 0.88 and m ranged from 1.45 + 0.015i to 1.56 + 0.05i, in good accordance with in situ aircraft measurements. The final data set of the aerosol microphysical properties along with the water vapor and temperature profiles were incorporated into the ISORROPIA model to infer an in situ aerosol composition consistent with the retrieved m and ω values. The retrieved aerosol chemical composition in the 2–3 km height region gave a variable range of sulfate (0–60%) and organic carbon (OC) content (0–50%), although the OC content increased (up to 50%) and the sulfate content dropped (up to 30%) around 3 km height; in connection with the retrieved low ω value (0.63), indicates the presence of absorbing biomass burning smoke mixed with urban haze. Finally, the retrieved aerosol microphysical properties were compared with column-integrated sunphotometer data.

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