Christopher Pöhlker
A5114376351- Atmospheric chemistry and aerosols
- Atmospheric aerosols and clouds
- Air Quality and Health Impacts
- Atmospheric Ozone and Climate
- Indoor Air Quality and Microbial Exposure
- Environmental and biological studies
- Air Quality Monitoring and Forecasting
- Aeolian processes and effects
- Atmospheric and Environmental Gas Dynamics
- Geography and Environmental Studies
- Lichen and fungal ecology
- Plant responses to elevated CO2
- COVID-19 impact on air quality
- Allergic Rhinitis and Sensitization
- Geochemistry and Elemental Analysis
- Remote Sensing in Agriculture
- Geochemistry and Geologic Mapping
- Climate variability and models
- Climate Change Communication and Perception
- Infection Control and Ventilation
- Inhalation and Respiratory Drug Delivery
- Plant Water Relations and Carbon Dynamics
- Biocrusts and Microbial Ecology
- Geological and Geochemical Analysis
- Polar Research and Ecology
Max Planck Institute for Chemistry
2016-2025
Max Planck Institute for Biogeochemistry
2011-2023
University of Applied Sciences Mainz
2019
Scripps Institution of Oceanography
2019
University of California, San Diego
2019
Naturalis Biodiversity Center
2019
Laboratoire de Météorologie Physique
2016-2017
Universidade Federal de Uberlândia
2017
Université Clermont Auvergne
2017
Max Planck Society
2014-2015
Aerosols of biological origin play a vital role in the Earth system, particularly interactions between atmosphere, biosphere, climate, and public health. Airborne bacteria, fungal spores, pollen, other bioparticles are essential for reproduction spread organisms across various ecosystems, they can cause or enhance human, animal, plant diseases. Moreover, serve as nuclei cloud droplets, ice crystals, precipitation, thus influencing hydrological cycle climate. The sources, abundance,...
Up with ultrafine aerosol particles Ultrafine (smaller than 50 nanometers in diameter) have been thought to be too small affect cloud formation. Fan et al. show that this is not the case. They studied effect of urban pollution transported into otherwise nearly pristine atmosphere Amazon. Condensational growth water droplets around tiny releases latent heat, thereby intensifying atmospheric convection. Thus, anthropogenic may exert a more important influence on formation processes previously...
Abstract. Bioaerosols are relevant for public health and may play an important role in the climate system, but their atmospheric abundance, properties, sources not well understood. Here we show that concentration of airborne biological particles a North American forest ecosystem increases significantly during rain bioparticles closely correlated with ice nuclei (IN). The greatest increase IN occurred size range 2–6 μm, which is characteristic bacterial aggregates fungal spores. By DNA...
Abstract. Primary biological aerosol particles (PBAP) are an important subset of air particulate matter with a substantial contribution to the organic fraction and potentially strong effects on public health climate. Recent progress has been made in PBAP quantification by utilizing real-time bioaerosol detectors based principle that specific molecules origin such as proteins, coenzymes, cell wall compounds pigments exhibit intrinsic fluorescence. The properties many fluorophores have well...
Abstract. The Amazon Basin plays key roles in the carbon and water cycles, climate change, atmospheric chemistry, biodiversity. It has already been changed significantly by human activities, more pervasive change is expected to occur coming decades. therefore essential establish long-term measurement sites that provide a baseline record of present-day climatic, biogeochemical, conditions will be operated over decades monitor region, as perturbations increase future. Tall Tower Observatory...
The fine particles serving as cloud condensation nuclei in pristine Amazonian rainforest air consist mostly of secondary organic aerosol. Their origin is enigmatic, however, because new particle formation the atmosphere not observed. Here, we show that growth aerosol can be initiated by potassium-salt-rich emitted biota rainforest. These act seeds for low- or semi-volatile compounds from atmospheric gas phase multiphase oxidation isoprene and terpenes. Our findings suggest primary emission...
Abstract Certain primary biological aerosol particles (PBAPs) are known to have very high ice nucleating ability under mixed‐phase cloud conditions. However, since the abundances of nucleation active PBAPs in atmosphere generally thought be extremely small, their importance has remained uncertain. Here we present evidence for role as atmospheric nuclei (IN) at temperatures ranging from about −34°C −9°C a midlatitude ponderosa pine forest ecosystem summertime. Our measurements show that...
Abstract The Observations and Modeling of the Green Ocean Amazon 2014–2015 (GoAmazon2014/5) experiment took place around urban region Manaus in central Amazonia across 2 years. pollution plume was used to study susceptibility gases, aerosols, clouds, rainfall human activities a tropical environment. Many aspects air quality, weather, terrestrial ecosystems, climate work differently tropics than more thoroughly studied temperate regions Earth. GoAmazon2014/5, cooperative project Brazil,...
Abstract Between 1 September and 4 October 2014, a combined airborne ground-based measurement campaign was conducted to study tropical deep convective clouds over the Brazilian Amazon rain forest. The new German research aircraft, High Altitude Long Range Research Aircraft (HALO), modified Gulfstream G550, extensive instrumentation were deployed in near Manaus (State of Amazonas). part German–Brazilian Aerosol, Cloud, Precipitation, Radiation Interactions Dynamics Convective Cloud...
Abstract. Airborne observations over the Amazon Basin showed high aerosol particle concentrations in upper troposphere (UT) between 8 and 15 km altitude, with number densities (normalized to standard temperature pressure) often exceeding those planetary boundary layer (PBL) by 1 or 2 orders of magnitude. The measurements were made during German–Brazilian cooperative aircraft campaign ACRIDICON–CHUVA, where ACRIDICON stands for Aerosol, Cloud, Precipitation, Radiation Interactions Dynamics...
Quantifying the aerosol/cloud-mediated radiative effect at a global scale requires simultaneous satellite retrievals of cloud condensation nuclei (CCN) concentrations and base updraft velocities ( W b ). Hitherto, inability to do so has been major cause high uncertainty regarding anthropogenic forcing. This can be addressed by emerging capability estimating CCN boundary layer convective clouds from an operational polar orbiting weather satellite. Our methodology uses such as effective analog...
Outdoor field measurements of bioaerosols are performed within a wide range basic and applied scientific disciplines, each with its own goals, assumptions, terminology. This article contains brief reviews outdoor bioaerosol research from these diverse interests, emphasis on perspectives the atmospheric sciences. The focus is high-level discussion pressing questions, grand challenges, needs for cross-disciplinary collaboration. topics, in which measurement important, include (i) physics,...
Abstract During spring 2020, the COVID-19 pandemic caused massive reductions in emissions from industry and ground airborne transportation. To explore resulting atmospheric composition changes, we conducted BLUESKY campaign with two research aircraft measured trace gases, aerosols, cloud properties boundary layer to lower stratosphere. From 16 May 9 June performed 20 flights early lockdown phase over Europe Atlantic Ocean. We found up 50% nitrogen dioxide concentrations urban areas GOME-2B...
The pandemic of coronavirus disease 2019 has led to a renewed focus on the physicochemical properties droplets and aerosol particles that are exhaled during breathing, speaking, singing, coughing, sneezing. In this article, respiratory particles, including their number concentrations size distributions, as well formation mechanisms at different sites in system, reviewed. data literature synthesized via parametrization particle distribution using log-normal modes related origin sites.
Abstract. Size-resolved long-term measurements of atmospheric aerosol and cloud condensation nuclei (CCN) concentrations hygroscopicity were conducted at the remote Amazon Tall Tower Observatory (ATTO) in central Basin over a 1-year period full seasonal cycle (March 2014–February 2015). The provide climatology CCN properties characteristic Amazonian rain forest site.The continuously cycled through 10 levels supersaturation (S = 0.11 to 1.10 %) span particle size range from 20 245 nm. mean...
Abstract. Aerosol–cloud interactions (ACI) constitute the single largest uncertainty in anthropogenic radiative forcing. To reduce uncertainties and gain more confidence simulation of ACI, models need to be evaluated against observations, particular measurements cloud condensation nuclei (CCN). Here we present a data set – ready used for model validation long-term observations CCN number concentrations, particle size distributions chemical composition from 12 sites on 3 continents. Studied...
Abstract It has long been known that precipitation can impact atmospheric aerosol, altering number concentrations and size‐dependent composition. Such effects result from competing mechanisms: remove particles through wet deposition, or lead to the emission of mechanical ejection, biological processes, re‐suspension associated wind gusts. These feed back into hydrologic cycle by serving as cloud nuclei. In this study, we investigated how at a forested site impacted concentration composition...
Abstract. Atmospheric particles of biological origin, also referred to as bioaerosols or primary aerosol (PBAP), are important various human health and environmental systems. There has been a recent steep increase in the frequency published studies utilizing commercial instrumentation based on ultraviolet laser/light-induced fluorescence (UV-LIF), such WIBS (wideband integrated bioaerosol sensor) UV-APS (ultraviolet aerodynamic particle sizer), for detection both outdoors built environment....
Abstract. Primary biological aerosol particles (PBAP) are important factors in atmospheric cycling, climate, and public health. Pollen is a major fraction of PBAP receiving increasing attention due to its high allergenic potential the associated impacts on personal life quality economy. Recently, autofluorescence-based techniques have proven be valuable tools for real time, situ quantification classification PBAP. First studies suggest that autofluorescence pollen may sufficiently selective...
Abstract. Size-resolved measurements of atmospheric aerosol and cloud condensation nuclei (CCN) concentrations hygroscopicity were conducted over a full seasonal cycle at the remote Amazon Tall Tower Observatory (ATTO, March 2014–February 2015). In preceding companion paper, we presented annually seasonally averaged data parametrizations (Part 1; Pöhlker et al., 2016a). present study 2), analyze key features implications CCN properties for following characteristic conditions: Empirically...
Abstract. Information on what aerosol particle types are the major sources of ice nucleating particles (INPs) in atmosphere is needed for climate predictions. To determine which immersion-mode INPs at a coastal site Western Canada, we investigated correlations between INP number concentrations and both different atmospheric meteorological conditions. We show that strongly correlated with fluorescent bioparticles −15 −25 °C, size distribution most consistent bioparticles. conclude biological...
Abstract. Bioaerosols pose risks to human health and agriculture may influence the evolution of mixed-phase clouds hydrological cycle on local regional scales. The availability reliability methods data abundance properties atmospheric bioaerosols, however, are rather limited. Here we analyze compare from different real-time ultraviolet laser/light-induced fluorescence (UV-LIF) instruments with results a culture-based spore sampler offline molecular tracers for airborne fungal spores in...
Abstract. The Amazon rainforest is a sensitive ecosystem experiencing the combined pressures of progressing deforestation and climate change. Its atmospheric conditions oscillate between biogenic biomass burning (BB) dominated states. further represents one few remaining continental places where atmosphere approaches pristine during occasional wet season episodes. Tall Tower Observatory (ATTO) has been established in central Amazonia to investigate complex interactions atmosphere. Physical...