The Spectral Radiative Properties of Stratus Clouds and Ice Surfaces in the Arctic

1997 ◽  
Author(s):  
Peter V. Hobbs
Keyword(s):  
Radiative Properties ◽  
The Arctic ◽  
Stratus Clouds ◽  
Ice Surfaces

Deployment of a Tethered-Balloon System for Microphysics and Radiative Measurements in Mixed-Phase Clouds at Ny-Ålesund and South Pole

2011 ◽  
Vol 28 (5) ◽  
pp. 656-670 ◽  
Author(s):  
R. Paul Lawson ◽  
Knut Stamnes ◽  
Jakob Stamnes ◽  
Pat Zmarzly ◽  
Jeff Koskuliks ◽  
...  
Keyword(s):  
Mixed Phase ◽  
Radiative Properties ◽  
The Arctic ◽  
South Pole ◽  
Tethered Balloon ◽  
The South ◽  
Stratus Clouds ◽  
Mixed Phase Clouds ◽  
Instrument Package ◽  
Balloon System

Abstract A tethered-balloon system capable of making microphysical and radiative measurements in clouds is described and examples of measurements in boundary layer stratus clouds in the Arctic and at the South Pole are presented. A 43-m3 helium-filled balloon lofts an instrument package that is powered by two copper conductors in the tether. The instrument package can support several instruments, including, but not limited to, a cloud particle imager; a forward-scattering spectrometer probe; temperature, pressure, humidity, and wind sensors; ice nuclei filters; and a 4-π radiometer that measures actinic flux at 500 and 800 nm. The balloon can stay aloft for an extended period of time (in excess of 24 h) and conduct vertical profiles up to about 1–2 km, contingent upon payload weight, wind speed, and surface elevation. Examples of measurements in mixed-phase clouds at Ny-Ålesund, Svalbard (79°N), and at the South Pole are discussed. The stratus clouds at Ny-Ålesund ranged in temperature from 0° to −10°C and were mostly mixed phase with heavily rimed ice particles, even when cloud-top temperatures were warmer than −5°C. Conversely, mixed-phase clouds at the South Pole contained regions with only water drops at temperatures as cold as −32°C and were often composed of pristine ice crystals. The radiative properties of mixed-phase clouds are a critical component of radiative transfer in polar regions, which, in turn, is a lynch pin for climate change on a global scale.

Radiative properties of the arctic aerosol

1982 ◽  
Vol 16 (12) ◽  
pp. 2967-2977 ◽  
Author(s):  
E.M Patterson ◽  
B.T Marshall ◽  
K.A Rahn
Keyword(s):  
Radiative Properties ◽  
The Arctic ◽  
Arctic Aerosol

Year-long observations of chemical properties of organic aerosols and cloud residuals at the Zeppelin Observatory, Svalbard

2021 ◽  
Author(s):  
Yvette Gramlich ◽  
Sophie Haslett ◽  
Karolina Siegel ◽  
Gabriel Freitas ◽  
Radovan Krejci ◽  
...  
Keyword(s):  
Cloud Condensation Nuclei ◽  
Aerosol Particles ◽  
Trace Gases ◽  
Chemical Properties ◽  
Radiative Properties ◽  
Cloud Formation ◽  
The Arctic ◽  
Arctic Clouds ◽  
Clear Sky ◽  
Air Inlet

<p>The number of cloud seeds, e.g. cloud condensation nuclei (CCN) and ice nucleation particles (INP), in the pristine Arctic shows a large range throughout the year, thereby influencing the radiative properties of Arctic clouds. However, little is known about the chemical properties of CCN and INP in this region. This study aims to investigate the chemical properties of aerosol particles and trace gases that are of importance for cloud formation in the Arctic environment, with focus on the organic fraction.</p><p>Over the course of one full year (fall 2019 until fall 2020), we deployed a filter-inlet for gases and aerosols coupled to a chemical ionization high-resolution time-of-flight mass spectrometer (FIGAERO-CIMS) using iodide as reagent ion at the Zeppelin Observatory in Svalbard (480 m a.s.l.), as part of the Ny-Ålesund Aerosol Cloud Experiment (NASCENT). The FIGAERO-CIMS is able to measure organic trace gases and aerosol particles semi-simultaneously. The instrument was connected to an inlet switching between a counterflow virtual impactor (CVI) inlet and a total air inlet. This setup allows to study the differences in chemical composition of organic aerosol particles and trace gases at molecular level that are involved in Arctic cloud formation compared to ambient non-activated aerosol.</p><p>We observed organic signal above background in both gas and particle phase all year round. A comparison between the gas phase mass spectra of cloud-free and cloudy conditions shows lower signal for some organics inside the cloud, indicating that some trace gases are scavenged by cloud hydrometeors whilst others are not. In this presentation we will discuss the chemical characteristics of the gases exhibiting different behavior during clear sky and cloudy conditions, and the implications for partitioning of organic compounds between the gas, aerosol particle and cloud hydrometeor (droplet/ice) phase.</p>

Dependence of radiative properties of Arctic stratus clouds on cloud microstructure

1983 ◽  
Vol 10 (12) ◽  
pp. 1188-1191 ◽  
Author(s):  
Si-Chee Tsay ◽  
Kolf Jayaweera ◽  
Knut Stamnes
Keyword(s):  
Radiative Properties ◽  
Stratus Clouds

scholarly journals Cloud Microphysical Properties Retrieved from Downwelling Infrared Radiance Measurements Made at Eureka, Nunavut, Canada (2006–09)

2014 ◽  
Vol 53 (3) ◽  
pp. 772-791 ◽  
Author(s):  
Christopher J. Cox ◽  
David D. Turner ◽  
Penny M. Rowe ◽  
Matthew D. Shupe ◽  
Von P. Walden
Keyword(s):  
Particle Size ◽  
Heat Budget ◽  
Cloud Microphysics ◽  
Radiative Properties ◽  
The Arctic ◽  
Temperature Phase ◽  
Research Station ◽  
Remote Sensors ◽  
Microphysical Properties ◽  
Infrared Radiances

AbstractThe radiative properties of clouds are related to cloud microphysical and optical properties, including water path, optical depth, particle size, and thermodynamic phase. Ground-based observations from remote sensors provide high-quality, long-term, continuous measurements that can be used to obtain these properties. In the Arctic, a more comprehensive understanding of cloud microphysics is important because of the sensitivity of the Arctic climate to changes in radiation. Eureka, Nunavut (80°N, 86°25′W, 10 m), Canada, is a research station located on Ellesmere Island. A large suite of ground-based remote sensors at Eureka provides the opportunity to make measurements of cloud microphysics using multiple instruments and methodologies. In this paper, cloud microphysical properties are presented using a retrieval method that utilizes infrared radiances obtained from an infrared spectrometer at Eureka between March 2006 and April 2009. These retrievals provide a characterization of the microphysics of ice and liquid in clouds with visible optical depths between 0.25 and 6, which are a class of clouds whose radiative properties depend greatly on their microphysical properties. The results are compared with other studies that use different methodologies at Eureka, providing context for multimethod perspectives. The authors’ findings are supportive of previous studies, including seasonal cycles in phase and liquid particle size, weak temperature–phase dependencies, and frequent occurrences of supercooled water. Differences in microphysics are found between mixed-phase and single-phase clouds for both ice and liquid. The Eureka results are compared with those obtained using a similar retrieval technique during the Surface Heat Budget of the Arctic Ocean (SHEBA) experiment.

Comparison of Arctic cloud properties over sea ice and open ocean based on airborne spectral solar remote sensing

2021 ◽  
Author(s):  
Marcus Klingebiel ◽  
André Ehrlich ◽  
Elena Ruiz-Donoso ◽  
Manfred Wendisch
Keyword(s):  
Remote Sensing ◽  
Sea Ice ◽  
Open Water ◽  
Open Ocean ◽  
Arctic Sea Ice ◽  
Radiative Properties ◽  
Radiation Budget ◽  
The Arctic ◽  
Liquid Water Path ◽  
Cloud Properties

<p>Over the last decades, the Arctic has experienced an enhanced warming, which is known as Arctic amplification. This process leads to a decrease in the amount of Arctic sea ice, which is linked by different feedback mechanisms to clouds and the related radiative properties. To analyze how the properties of these Arctic clouds could change in a future sea ice free Arctic, we completed three airborne campaigns in the marginal sea ice zone between 2017 and 2020 covering summer and winter conditions. During these campaigns we performed in-situ and remote sensing measurements to study cloud micro- and macrophysical properties and analyzed how these clouds affect the radiation budget. In this study we use the passive remote sensing measurements from these airborne observations to retrieve cloud top effective radius, liquid water path and cloud optical thickness. We found that these cloud properties differ between a sea ice surface and over open water. The airborne observations are supported by an analysis of the cloud product from the MODIS satellite. The systematic differences of clouds over sea ice and the open ocean suggests that clouds may change in a future warming Arctic environment.</p>

The fog/low stratus clouds in the Arctic: detection with multispectral satellite imagery

2020 ◽  
Author(s):  
Daria Tatsii ◽  
Natalia Fedoseeva
Keyword(s):  
Satellite Imagery ◽  
Complex Structure ◽  
Far Infrared ◽  
The Arctic ◽  
Underlying Surface ◽  
Polar Regions ◽  
Stratus Clouds ◽  
Spectral Bands ◽  
Multispectral Satellite Imagery ◽  
Important Challenge

<p>            The safe operation of aviation and shipping, particularly in areas of insufficient coverage of automatic meteorological stations in the Arctic requires accurate interpretation of satellite images. Operational detection of fog and low stratus clouds and recognizing of them on the background of snow and ice cover and cloudiness of the upper layer is very important challenge. </p><p>           The verified images obtained by Aqua and Terra satellites with a scanning radiometer MODIS, which operates in 36 spectral bands, with wavelengths from 0.4 µm to 14.4 µm, were collected.  With the Beam VISAT 5.0 software, which was designed to work with satellite data in raster format, thematic digital techniques of satellite multispectral information, based on difference in the values of the integral brightness of the images, both in optical and far-infrared ranges of the spectrum, have been developed.  These techniques, models of additive color synthesis, improve the quality of interpretation of fogs and low stratus clouds in terms of the complex structure of cloudiness and underlying surface in polar regions. Developed RGB combinations, which are based on the selected MODIS bands are:</p><ol><li>RGB (1.6 µm; 0.8 µm; 0.6 µm)</li> <li>RGB (0.8 µm; 3.9-8.7 µm; 10.8 µm)</li> <li>RGB (0.8 µm; 1.6 µm; 3.9-8.7 µm)</li> <li>RGB ((0-12)-(0-11) µm, (0-11)-(0-3.8) µm, (0-11) µm)</li> </ol><p>          Analysis of the obtained images has shown that the developed models of color synthesis help to distinguish the fog/low stratus clouds under different conditions of cloudiness and underlying surface accurately.</p><p>Key words: remote sensing, satellite imagery, additive color synthesis, fog, low stratus clouds, polar regions</p>

Can Ice-Nucleating Aerosols Affect Arctic Seasonal Climate?

2007 ◽  
Vol 88 (4) ◽  
pp. 541-550 ◽  
Author(s):  
Anthony J. Prenni ◽  
Jerry Y. Harrington ◽  
Michael Tjernström ◽  
Paul J. DeMott ◽  
Alexander Avramov ◽  
...  
Keyword(s):  
Liquid Water ◽  
Surface Flux ◽  
Diffusion Chamber ◽  
Liquid Water Content ◽  
Atmospheric Modeling ◽  
Mixed Phase ◽  
The Arctic ◽  
Radiative Energy ◽  
Stratus Clouds ◽  
North Slope Of Alaska

Mixed-phase stratus clouds are ubiquitous in the Arctic and play an important role in climate in this region. However, climate and regional models have generally proven unsuccessful at simulating Arctic cloudiness, particularly during the colder months. Specifically, models tend to underpredict the amount of liquid water in mixed-phase clouds. The Mixed-Phase Arctic Cloud Experiments (M-PACE), conducted from late September through October 2004 in the vicinity of the Department of Energy's Atmospheric Radiation Measurement (ARM) North Slope of Alaska field site, focused on characterizing low-level Arctic stratus clouds. Ice nuclei (IN) measurements were made using a continuous-flow ice thermal diffusion chamber aboard the University of North Dakota's Citation II aircraft. These measurements indicated IN concentrations that were significantly lower than those used in many models. Using the Regional Atmospheric Modeling System (RAMS), we show that these low IN concentrations, as well as inadequate parameterizations of the depletion of IN through nucleation scavenging, may be partially responsible for the poor model predictions. Moreover, we show that this can lead to errors in the modeled surface radiative energy budget of 10–100 Wm−2. Finally, using the measured IN concentrations as input to RAMS and comparing to a mixed-phase cloud observed during M-PACE, we show excellent agreement between modeled and observed liquid water content and net infrared surface flux.

scholarly journals The complex response of Arctic aerosol to sea-ice retreat

2014 ◽  
Vol 14 (14) ◽  
pp. 7543-7557 ◽  
Author(s):  
J. Browse ◽  
K. S. Carslaw ◽  
G. W. Mann ◽  
C. E. Birch ◽  
S. R. Arnold ◽  
...  
Keyword(s):  
Sea Ice ◽  
Dimethyl Sulfide ◽  
Cloud Condensation Nuclei ◽  
Arctic Sea Ice ◽  
Sea Salt ◽  
Radiative Properties ◽  
Climate Feedback ◽  
The Arctic ◽  
Ice Retreat ◽  
Sea Ice Retreat

Abstract. Loss of summertime Arctic sea ice will lead to a large increase in the emission of aerosols and precursor gases from the ocean surface. It has been suggested that these enhanced emissions will exert substantial aerosol radiative forcings, dominated by the indirect effect of aerosol on clouds. Here, we investigate the potential for these indirect forcings using a global aerosol microphysics model evaluated against aerosol observations from the Arctic Summer Cloud Ocean Study (ASCOS) campaign to examine the response of Arctic cloud condensation nuclei (CCN) to sea-ice retreat. In response to a complete loss of summer ice, we find that north of 70° N emission fluxes of sea salt, marine primary organic aerosol (OA) and dimethyl sulfide increase by a factor of ~ 10, ~ 4 and ~ 15 respectively. However, the CCN response is weak, with negative changes over the central Arctic Ocean. The weak response is due to the efficient scavenging of aerosol by extensive drizzling stratocumulus clouds. In the scavenging-dominated Arctic environment, the production of condensable vapour from oxidation of dimethyl sulfide grows particles to sizes where they can be scavenged. This loss is not sufficiently compensated by new particle formation, due to the suppression of nucleation by the large condensation sink resulting from sea-salt and primary OA emissions. Thus, our results suggest that increased aerosol emissions will not cause a climate feedback through changes in cloud microphysical and radiative properties.

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