Ruprecht Jaenicke

Johannes Gutenberg-Universität Mainz | JGU · Institute for Atmospheric Physics

Atmospheric aerosol particles of biological origin are a very diverse group of biological materials and structures, including microorganisms, dispersal units, fragments and excretions of biological organisms. In recent years, the impact of biological aerosol particles on atmospheric processes has been studied with increasing intensity, and a wealth...

A B S T R A C T Atmospheric aerosol particles of biological origin are a very diverse group of biological materials and structures, including microorganisms, dispersal units, fragments and excretions of biological organisms. In recent years, the impact of biological aerosol particles on atmospheric processes has been studied with increasing intensi...

Atmospheric aerosol particles of biological origin are a very diverse group of biological materials and structures, including microorganisms, dispersal units, fragments and excretions of biological organisms. In recent years, the impact of biological aerosol particles on atmospheric processes has been studied with increasing intensity, and a wealth...

For the past 200 years, the field of aerobiology has explored the abundance, diversity, survival and transport of micro-organisms in the atmosphere. Micro-organisms have been explored as passive and severely stressed riders of atmospheric transport systems. Recently, an interest in the active roles of these micro-organisms has emerged along with pr...

Ice nuclei (IN) initiate the formation of primary ice in tropospheric clouds. In mixed phase clouds the primary ice crystals can grow very fast and form precipitation by the Bergeron-Findeisen process [Findeisen, 1938] at the expense of evaporating water droplets. Thus, IN are essential for the development of precipitation in mixed phase clouds at...

In this work we present the setup and first tests of our new BIO IN detector. This detector was constructed to classify atmospheric ice nuclei (IN) for their biological content. It is designed to be coupled to the Fast Ice Nucleus CHamber FINCH. If one particle acts as an ice nucleus, it will be at least partly covered with ice at the end of the de...

In this work we present the setup and first tests of our new BIO IN detector. This detector is designed to classify atmospheric ice nuclei (IN) for their biological content. Biological material is identified via its auto-fluorescence (intrinsic fluorescence) after irradiation with UV radiation. Ice nuclei are key substances for precipitation develo...

The Saharan Mineral Dust Experiment (SAMUM) is dedicated to the understanding of the radiative effects of mineral dust. Two major field experiments were performed: A first joint field campaign took place at Ouarzazate and near Zagora, southern Morocco, from May 13 to June 7, 2006. Aircraft and ground based measurements of aerosol physical and chemi...

Ice formation in clouds is a subject of great practical and fundamental importance since the occurrence of ice particle initializes dramatic changes in the microphysical structure of the cloud, which finally ends in the formation of precipitation. The initially step of ice formation is largely unknown. Homogenous nucleation of ice occurs only below...

Ice nuclei (IN) initiate the formation of primary ice in tropospheric clouds. In mixed phase clouds the primary ice crystals can grow very fast by the Bergeron-Findeisen process (Findeisen, 1938) at the expense of evaporating water droplets, and form precipitation. Thus, IN are essential for the development of precipitation in mixed phase clouds in...

During the SAMUM 2006 field campaign in southern Morocco, physical and chemical properties of desert aerosols were measured. Mass concentrations ranging from 30 μg m−3 for PM2.5 under desert background conditions up to 300 000 μg m−3 for total suspended particles (TSP) during moderate dust storms were measured. TSP dust concentrations are correlate...

During the SAMUM 2006 field campaign in southern Morocco, physical and chemical properties of desert aerosols were measured. Mass concentrations ranging from 30

We present first results of our new developed Ice Nucleus (IN) counter FINCH from the sixth Cloud and Aerosol Characterization Experiment (CLACE 6) campaign at Jungfraujoch station, 3571 m asl. Measurements were made at the total and the ICE CVI inlet. Laboratory measurements of ice onset temperatures by FINCH are compared to those of the static di...

The natural, or nonanthropogenic, atmospheric aerosol is described in terms of four different aerosols: stratospheric, background, maritime, and continental. Two major processes, the dispersion of mechanically disintegrated material and the transformation of airborne precursors, are identified as the sources of the natural aerosol. It is shown that...

During the Saharan Mineral Dust Experiment SAMUM phases I and II aerosol mass concentrations and bulk mineralogical composition were measured at Tinfou ground station, Southern Morocco, in 2006 and at Praia airport, Island of Santiago, Cape Verde, in 2008.

Multi-year monitoring of atmospheric bioaerosol in Southwestern Siberia revealed the presence of a large number of various culturable microorganisms. It is known that viable microorganisms can cause directly or provoke different human diseases. It's very difficult to evaluate the danger represented by each microorganism to man directly. Therefore,...

Countless observations of the atmospheric aerosol reveal large concentration variabilities. Such variability is not characteristic for a colloid. It must have a certain degree of stability and that is not seen in the atmospheric aerosol. The question then is open if the atmospheric aerosol is really a colloid, an aerosol. On the other side, the atm...

For the past 200 years, the field of aerobiology has explored the abundance, diversity, survival and transport of micro-organisms in the atmosphere. Micro-organisms have been explored as passive and severely stressed riders of atmospheric transport systems. Recently, an interest in the active roles of these micro-organisms has emerged along with pr...

The contemporary atmosphere was created as a result of biological activity some two billion years ago. To this day, its natural composition is supported and modified, mostly through biological processes of trace gas production and destruction, while also involving physical and chemical degradation processes. The biosphere has a major influence on p...

We present first results of our new developed ice nucleus (IN) counter FINCH at the sixth Cloud and Aerosol Characterisation Experiment (CLACE 6) campaign at Jungfraujoch station 3,571 m a.s.l. Measurements were made at the total and the ICE CVI inlet. Keywords Heterogeneous nucleation, ice nucleus counter, cluster (times 10 pt)

Environmental context. Atmospheric biological particles have been largely overlooked in the past. While some microorganisms have been studied, the majority of other biological particles have not. The presence of these particles might force us to view the atmospheric aerosol differently. Abstract. Measurements of biological particles in the atmosphe...

IntroductionMethodologyAnalyses and Selected ResultsDiscussion and Conclusions

Significance of PBAPThe Size Distribution in the AtmosphereThe Size Distribution in RainwaterThe Size Distribution in Cloud WaterConclusions

Suspended atmospheric particles play a crucial role in any global climate scenario: They can both enforce and suppress radiative forcing. In developing climate modeling further, a deeper understanding of atmospheric aerosol is needed. Because of extreme local and temporal variations, proper incorporation of aerosols into models requires modeling of...

Oxygen isotope compositions were measured by ion microprobe in individual micrometer-sized quartz grains extracted from one aerosol sample collected on the Cape Verde Islands and from four surface samples (three soils and one sediment) representing potential source regions of aerosols in Western and Central Africa (Morocco, Algeria, Niger, and Chad...

Laboratory tests were conducted of the ice nucleating ability of four kinds of pollen in the immersion and the contact freezing modes. The diameters of the selected pollen were between 25 and 70 μm. The experiments were carried out at the Mainz vertical wind tunnel with freely suspended supercooled droplets at temperatures down to −28 °C. The immer...

Laboratory experiments are described where the water uptake by a variety of pollen was studied quantitatively, followed by the investigation of the ice nucleating ability of four kinds of pollen in the deposition and the condensation freezing modes. The diameters of the pollen selected for the freezing experiments were between 25 and 70 μm. The fre...

Samples from three different depths in the Hans Tausen ice core (82.5°N, 37.5°W) in Peary Land, North Greenland were examined. The aim was to determine the size distributions of the total and biological particles in the size range 0.2 μm < radius < 41.2 μm. To date, the concentration of the whole spectrum of biological microparticles including viru...

The Linke turbidity factor, which is defined as the ratio of the integral optical depth of the total extinction divided by the optical depth due to Rayleigh scattering only, is a convenient measure for the total load of atmospheric trace compounds in the vertical column (Louche et al. 1986). This analysis is performed from records of global and dif...

Rapid particle growth by the condensation of water vapour resulting from expansion in the inlet of particle sizing instruments such as optical particle counters and impactors was modelled. The corrected Mason diffusion growth equation extended to the application for particles beyond the continuum region has been found suitable. The influence of par...

During the field campaign, FELDEX 95 cloud water samples were collected and the insoluble particles were analysed by single particle analysis in order to determine the content of primary biological aerosol particles (PBAP). It is found that 25% of the total insoluble particles are biological ones. During cloud events with increasing wind velocity,...

Primary biological aerosol particles are a ubiquitouscomponent of the atmospheric aerosol and have greatimportance within the whole atmosphere. Besides theireffect on air hygiene (i.e. causing allergic diseases), theycontribute to cloud and rain development. They amountto almost 25% of the total number of aerosolparticles both in dry air and in clo...

The fixation of an isolating tar layer on the building roves of the faculty of sciences located at the south boundary of the city of Oujda (Morocco) was attempted. The activity was undertaken all along the working day time for a period starting 1st July 1998 and finishing 10th September 1998. Two sampling devices installed on the roof near the labo...

This study determined the size distribution of all biological material including viruses, bacteria, spores, pollen, plant debris and animal fragments present at different depths from the Hans Tausen Ice Cap in Peary Land (North Greenland). Results from scanning electron microscopy and energy dispersive X-ray analysis found a mean total concentratio...

The rapid condensational growth of aerosol particles in the inlet was investigated. Air flow in the nozzle was assumed to be steady, compressible and heat-conducting. CFX-FLOW3D algorithm was used for simulating the high speed turbulent air flow in the inlet nozzle. Focus was on a typical inlet nozzle of an optical particle counter with inner diame...

The concentration and chemical composition of aerosol particles in marine and continental air were evaluated. Aerosol samples, both of marine and continental origin, were taken ground-based on the island of Helgoland and on board of an aircraft above the North Sea. The particles were investigated in a scanning electron microscope. By interpreting t...

The ground-based HODAR (HOlographic Droplet and Aerosol Recording) of the University of Mainz has been operational since 1989 on the Kleiner Feldberg Mountain Observatory near Frankfurt/Main, Germany, in a `small volume' configuration. With this setup an air volume of approximately 1 l can be in situ recorded, which allows it to image all aerosol p...

During a complete year (April 1996–April 1997) impactor measurements were performed in the remote continental region of Lake Baikal/Siberia and were analysed by single-particles analysis to determine the content of primary biological aerosol particles. The results show an amount of 20% of the number concentration and almost 30% of the volume concen...

Ground based in-situ measurements on the small-scale structure of low-level stratiform clouds have been performed utilizing the HOlographic Droplet and Aerosol Recording system (HODAR) of the University of Mainz, Germany. 6 holograms recorded during stratus cloud events on the Kleiner Feldberg Taunus Mountain Observatory (Frankfurt, Germany) were r...

In 1993 the joint Russian-German Research Project ‘Arctic Haze’ started (see the Introduction and editorial note of this issue, by Jaenicke, Khattatov, Jaeschke and Leiterer). Besides CAO, four German groups were involved. To the present three airborne measuring campaigns have been performed. In total 251 h of flight within altitudes up to 8.7 km w...

This chapter demonstrates the relevance of biological aerosol particles as active participants in cloud forming processes. It uses an existing method for the determination of atmospheric biological aerosol particles to investigate rain-water samples and this size distribution in rainwater. Primary biological aerosol particles (PBAP) describe airbor...

Primary biological aerosol particles including pollen, spores, plant debris, epithelial cells, bacteria, algae, protozoa and viruses, are an ubiquitous component of the atmospheric aerosol, they are most probably present in all size ranges. Besides their effects on air hygiene and health, biological particles play an important role in cloud physics...

Recent data published in literature on global cloudiness and precipitation as well as data on updrafts in clouds and their liquid water contents allow us to estimate the global turnover of water vapor and liquid water in the atmosphere. From these turnover rates the global average capacity of clouds to uptake, store and release atmospheric aerosol...

Besides their effects on air hygiene and health, bioaerosol particles play an important role in cloud physics, for example, some bacteria are able to accumulate water and act as ice nuclei. For sampling aerosol particle impactors were used. The larger particles were sampled size fractionated with a free wing impactor while for the smaller ones an i...

Measurements of continental remote aerosol were carried out in the summer of 1991 and 1992. Different locations in Siberia were used for the measurements: near Lake Baikal and near the city of Novosibirsk. Our measurements reflect typical summertime conditions, and extrapolation to other seasons in Siberia is not possible.Aerosol size distributions...

During the EUROTRAC Ground Based Cloud Experiment (GCE) 1990, a newly developed HODAR (Holographic Droplet and Acrosol Recording) was operated for the first time to measure cloud droplet size distributions by recording Fraunhofer in-line holograms of small cloud sample volumes in situ and analyzing the holographic images in the laboratory. This tec...

A holographic droplet and aerosol recording (HODAR) designed to measure sizes and velocity vectors of cloud droplets and to determine sizes and shapes of other hydrometeors is described. The HODAR system covers the particle-size radii range greater than 3 microns. Holograms recorded during graupel precipitation events make it possible to differenti...

A basic assumption of numerical cloud modelling and cloud physics in general is that the cloud droplets and hydrometeors are randomly distributed in space. Previously published studies however suggest that there are deviations from a random distribution and mechanisms for “clustering” are conjectured.For this study five holograms of cloud droplet p...

The physical properties of an optical aerosol particle counter are simulated with a numerical algorithm showing the influence of monochromatic light scattering on the results of size distribution measurements. By using model size distribution as an input to the simulation, the oscillations of the theoretical light-scattering curve are seen to cause...

Tropospheric aerosols derive from many sources. They are distributed in the atmosphere through turbulence and direct atmospheric transport of air masses. They are removed by precipitation, coagulation, and sedimentation (dry impaction). One of the sources is nonprecipitating clouds. Clouds serve not only as chemical reactors, but also as particle s...

Evaluations of measurements of the tropospheric surface condensation nuclei at the German Antarctic station for the last 8 years are presented. They show clearly the annual variation of the concentration with a maximum in austral summer, as previously seen by other investigators. In addition, a pronounced increase of the concentration of 9.63% per...

Evaluations of measurements of the tropospheric surface condensation nuclei at the German Antarctic station for the last 8 years are presented. They show clearly the annual variation of the concentration with a maximum in austral summer, as previously seen by other investigators. In addition, a pronounced increase of the concentration of 9.63% per...

The least investigated atmospheric aerosol is the one in remote continental areas. In this study, measurements of condensation nuclei size distributions near Lake Baikal, Siberia, were performed. Data for total aerosol number concentration and aerosol size distribution were obtained. The measurement equipment consisted of a TSI screen diffusion bat...

The analysis of nearly continuous records of surface-based atmospheric condensation nuclei concentration (CNC) since 1984 up to the present at the Georg von Neumayer-Station (GvN) shows clearly: - an annual cycle of CNC with low values in winter time; - a significantly increasing frequency of CNC of more than 1000 particles per cm3 over the years.

The relevance of biological aerosol will be demonstrated. A method to determine the size distribution of the biological aerosols is shown, which gives the opportunity to determine a lower limit of the biological particles. For evaluation a light microscope and a scanning electron microscope equipped with an energy dispersive x-ray spectrometer are...

This paper summarizes the state-of-the-art and the research needs in the areas of aerosol residence-time assessments, deposition modelling, and understanding of aerosols in biogeochemistry. Research needs are emphasized from a systems perspective of global environmental change. Although fundamental quantitative knowledge is lacking, some qualitativ...

In view of the short residence time of the aerosol in the atmosphere, knowledge of its distribution in space is essential for the understanding of many processes associated with this distribution, for example, the formation of clouds and hence of the entire cloud cover over the Earth's sphere. This review considers both the distribution of aerosol...

This paper summarizes the state-of-the art and the research needs in the areas of aerosol residence-time assessments, deposition modelling, and understanding of aerosols in biogeochemistry. Research needs are emphasized from a systems perspective of global environmental change. Although fundamental quantitative knowledge is lacking, some qualitativ...

Without Abstract

In wind tunnel experiments sub-μm aerosol size distributions have been measured within the turbulent boundary layer above a sand surface that has been under the eroding influence of a quantified flow of saltating glass beads (50 μm radius). An optical particle counter covering a particle size radius range from 0.33 to 1.01 μm was used for measuring...

Whether in classical networks such as meteorological networks of in more recent ones of atmospheric chemistry, a wealth of data is at hand. These data have been evaluated in a manner depending on the purpose of the network. However, much more information is hidden in these time series and waits for discovery. Only the imagination of scientists is n...

The feasibility of determining atmospheric turbidity from the burned traces of Campbell-Stokes sunshine recorders during cloudless sunsets and sunrises is examined experimentally. Results show that atmospheric turbidity can be determined in this way and can provide data for climatological research over the period of existing sunshine records. Howev...

The photometer is equipped with nine narrow-banded interference filters in the wavelengths range 0. 4-1. 05 mu m. Some filters have been selected to be free of absorption bands of atmospheric trace gases. Others are placed to be effected by NO//2, O//3 and H//2O, respectively. The spectral portion of the sun radiation penetrating the filters is mea...

A handheld sunphotometer has been developed and is described. It operates for 9 wavelengths in the visible and near infrared. The sensitivity range is rather broad, so it can be used in turbid as well as clear atmospheres. The operation is simple, and a digital readout helps prevent operator biases. The instrument is sun powered and suitable for ne...

Recent work on atmospheric aerosols that illustrates the complex nature of the aerosol chemical and physical system is reviewed. The studies show that man has had a great effect on the global budgets of certain species, especially sulfur and nitrogen, that play a dominant role in the atmospheric aerosol system. It is considered conceivable that the...