In-situ airborne observations of the microphysical properties of the Arctic tropospheric aerosol during late spring and summer

Tellus B ◽  
2008 ◽  
Vol 60 (3) ◽  
Author(s):  
Ann-Christine Engvall ◽  
Radovan Krejci ◽  
Johan Ström ◽  
Andreas Minikin ◽  
Renate Treffeisen ◽  
...  
Keyword(s):  
Late Spring ◽  
The Arctic ◽  
Microphysical Properties ◽  
Tropospheric Aerosol

scholarly journals In-situ airborne observations of the microphysical properties of the Arctic tropospheric aerosol during late spring and summer

Tellus B ◽  
2008 ◽  
Vol 60 (3) ◽  
pp. 392-404 ◽  
Author(s):  
Ann-Christine Engvall ◽  
Radovan Krejci ◽  
Johan Ström ◽  
Andreas Minikin ◽  
Renate Treffeisen ◽  
...  
Keyword(s):  
Late Spring ◽  
The Arctic ◽  
Microphysical Properties ◽  
Tropospheric Aerosol

scholarly journals Microphysical properties of synoptic scale polar stratospheric clouds: in situ measurements of unexpectedly large HNO<sub>3</sub> containing particles in the Arctic vortex

2014 ◽  
Vol 14 (8) ◽  
pp. 12071-12120 ◽  
Author(s):  
S. Molleker ◽  
S. Borrmann ◽  
H. Schlager ◽  
B. Luo ◽  
W. Frey ◽  
...  
Keyword(s):  
Nitric Acid ◽  
Scattered Light ◽  
Stratospheric Ozone ◽  
The Arctic ◽  
Size Distributions ◽  
Synoptic Scale ◽  
Particle Composition ◽  
Mixing Ratios ◽  
Microphysical Properties

Abstract. In January 2010 and December 2011 synoptic scale PSC fields were probed during seven flights of the high altitude research aircraft M-55 Geophysica within the RECONCILE (Reconciliation of essential process parameters for an enhanced predictability of Arctic stratospheric ozone loss and its climate interaction.) and the ESSenCe (ESSenCe: ESA Sounder Campaign) projects. Particle size distributions in a diameter range between 0.46 μm and 40 μm were recorded simultaneously by up to four different optical in situ instruments. Three of these particle instruments are based on the detection of forward scattered light by single particles. The fourth instrument is a grey scale optical array imaging probe. Optical particle diameters of up to 35 μm were detected with particle number densities and total particle volumes exceeding previous Arctic measurements. Also, gas phase and particle bound NOy were measured, as well as water vapor concentrations, and other variables. Two remote sensing particle instruments, the Miniature Aerosol Lidar (MAL) and the backscatter sonde (MAS, Multiwavelenght Aerosol Scatterometer) showed the synoptic scale of the encountered PSCs. The particle mode below 2 μm in size diameter has been identified as supercooled ternary solution droplets (STS). The PSC particles in the size range above 2 μm in diameter are considered to consist of nitric acid hydrates or ice, and the particles' high HNO3 content was confirmed by the NOy instrument. Assuming a particle composition of nitric acid trihydrate (NAT), the optically measured size distributions result in particle-phase HNO3 mixing ratios exceeding available stratospheric values. In particular, with respect to the denitrification by sedimentation of large HNO3-contaning particles, generally considered as NAT, our new measurements raise questions concerning composition, shape and nucleation pathways. Measurement uncertainties are discussed concerning probable overestimations of measured particle sizes and volumes. We hypothesize that either a strong asphericity or the particle composition (e.g. water-ice coated with NAT) could explain our observations.

scholarly journals Airborne observations of a subvisible midlevel Arctic ice cloud: microphysical and radiative characterization

2009 ◽  
Vol 9 (1) ◽  
pp. 595-634
Author(s):  
A. Lampert ◽  
A. Ehrlich ◽  
A. Dörnbrack ◽  
O. Jourdan ◽  
J.-F. Gayet ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Thermal Infrared ◽  
Airborne Lidar ◽  
Radiative Properties ◽  
The Arctic ◽  
Cloud Base ◽  
Effective Diameter ◽  
Ice Cloud ◽  
Tropospheric Aerosol

Abstract. During the Arctic Study of Tropospheric Aerosol, Clouds and Radiation (ASTAR) campaign, which was conducted in March and April 2007, an optically thin ice cloud was observed at around 3 km altitude south of Svalbard. The microphysical and radiative properties of this particular subvisible midlevel cloud were investigated with complementary remote sensing and in-situ instruments. Collocated airborne lidar remote-sensing and spectral solar radiation measurements were performed at a flight altitude of 2300 m below the cloud base. Under almost stationary atmospheric conditions, the same subvisible midlevel cloud was probed with various in-situ sensors roughly 30 min later. From individual ice crystal samples detected with the Cloud Particle Imager and the ensemble of particles measured with the Polar Nephelometer, we retrieved the single-scattering albedo, the scattering phase function as well as the volume extinction coefficient and the effective diameter of the crystal population. Furthermore, a lidar ratio of 21 (±6) sr was deduced by two independent methods. These parameters in conjunction with the cloud optical thickness obtained from the lidar measurements were used to compute spectral and broadband radiances and irradiances with a radiative transfer code. The simulated results agreed with the observed spectral downwelling radiance within the range given by the measurement uncertainty. Furthermore, the broadband radiative simulations estimated a net (solar plus thermal infrared) radiative forcing of the subvisible midlevel ice cloud of −0.4 W m−2 (−3.2 W m−2 in the solar and +2.8 W m−2 in the thermal infrared wavelength range).

scholarly journals Coincident In-situ and Triple-Frequency Radar Airborne Observations in the Arctic

2021 ◽  
Author(s):  
Cuong M. Nguyen ◽  
Mengistu Wolde ◽  
Alessandro Battaglia ◽  
Leonid Nichman ◽  
Natalia Bliankinshtein ◽  
...  
Keyword(s):  
National Research Council ◽  
Characteristic Size ◽  
The Arctic ◽  
Dual Frequency ◽  
Microphysical Properties ◽  
Triple Frequency ◽  
W Band ◽  
Modelling Studies ◽  
Frequency Ratios

Abstract. This paper describes X-Ka-W-band airborne radar observations and almost perfectly co-located in situ microphysical measurements on board the National Research Council Canada (NRC) Convair-580 aircraft from the Radar Snow Experiment (RadSnowExp). Over 12 hours of flight data with more than 3.4 hours in non-Rayleigh regions for at least one of the radar frequencies provide a unique opportunity for studying the relationship between cloud microphysical properties and radar dual-frequency ratios (DFR). The results from this study are consistent with the main findings of previous modelling studies with specific regions of the DFR plane associated with unique scattering properties of different ice habits, especially in riming conditions. Moreover, the datasets could be used to produce look-up-tables for retrieving cloud bulk density and characteristic size.

scholarly journals Microphysical and optical properties of Arctic mixed-phase clouds – the 9 April 2007 case study

2009 ◽  
Vol 9 (3) ◽  
pp. 11333-11366 ◽  
Author(s):  
J.-F. Gayet ◽  
G. Mioche ◽  
A. Dörnbrack ◽  
A. Ehrlich ◽  
A. Lampert ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Liquid Water ◽  
Mixed Phase ◽  
Ice Crystals ◽  
The Arctic ◽  
Small Scale ◽  
Water Droplets ◽  
Backscatter Signal ◽  
Tropospheric Aerosol

Abstract. Airborne measurements in Arctic boundary-layer stratocumulus were carried out near Spitsbergen on 9 April 2007 during the Arctic Study of Tropospheric Aerosol, Clouds and Radiation (ASTAR) campaign. A unique set of co-located observations is used to describe the cloud properties, including detailed in situ cloud microphysical and radiation measurements along with airborne and co-located spaceborne remote sensing data (Lidar on Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations [CALIPSO] and radar on CloudSat satellites). The CALIPSO profiles evidence a cloud top temperature which varies between −24°C and −21°C. The in situ cloud observations reveal that the attenuated backscatter signal from lidar along the aircraft trajectory is linked with the presence of liquid water and therefore confirms a cloud top layer dominated by liquid-water, which is a common feature observed in Arctic mixed-phase stratocumulus clouds. A low concentration of quite large ice crystals are also evidenced up to the cloud top and lead to significant CloudSat radar echo. Since the ratio of the extinction of liquid water droplets and ice crystals is high the broadband radiative effects near the cloud top are mostly dominated by water droplets. CloudSat observations as well as in situ measurements reveal high reflectivity factors (up to 15 dBZ) and precipitation rates (1 mm h−1). This feature is due to efficient ice production processes. About 25% of the theoretically available liquid water is converted into ice water with large ice crystals which precipitate. According to an estimation of the mean cloud cover, a considerable value of 106 m3 h−1 of fresh water could be settled over the Greenland sea pool. European Centre for Medium-Range Weather Forecast (ECMWF) operational analyses reproduces the variation of the boundary layer height along the flight track. However, small-scale features in the observed cloud field cannot be resolved by ECMWF analysis. Furthermore, ECMWF's diagnostic partitioning of the condensed water into ice and liquid reveals serious shortcomings for Arctic mixed-phased clouds. Too much ice is modeled.

scholarly journals Microphysical and radiative characterization of a subvisible midlevel Arctic ice cloud by airborne observations – a case study

2009 ◽  
Vol 9 (8) ◽  
pp. 2647-2661 ◽  
Author(s):  
A. Lampert ◽  
A. Ehrlich ◽  
A. Dörnbrack ◽  
O. Jourdan ◽  
J.-F. Gayet ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Thermal Infrared ◽  
Airborne Lidar ◽  
Radiative Properties ◽  
The Arctic ◽  
Cloud Base ◽  
Effective Diameter ◽  
Ice Cloud ◽  
Tropospheric Aerosol

Abstract. During the Arctic Study of Tropospheric Aerosol, Clouds and Radiation (ASTAR) campaign, which was conducted in March and April 2007, an optically thin ice cloud was observed south of Svalbard at around 3 km altitude. The microphysical and radiative properties of this particular subvisible midlevel cloud were investigated with complementary remote sensing and in situ instruments. Collocated airborne lidar remote sensing and spectral solar radiation measurements were performed at a flight altitude of 2300 m below the cloud base. Under almost stationary atmospheric conditions, the same subvisible midlevel cloud was probed with various in situ sensors roughly 30 min later. From individual ice crystal samples detected with the Cloud Particle Imager and the ensemble of particles measured with the Polar Nephelometer, microphysical properties were retrieved with a bi-modal inversion algorithm. The best agreement with the measurements was obtained for small ice spheres and deeply rough hexagonal ice crystals. Furthermore, the single-scattering albedo, the scattering phase function as well as the volume extinction coefficient and the effective diameter of the crystal population were determined. A lidar ratio of 21(±6) sr was deduced by three independent methods. These parameters in conjunction with the cloud optical thickness obtained from the lidar measurements were used to compute spectral and broadband radiances and irradiances with a radiative transfer code. The simulated results agreed with the observed spectral downwelling radiance within the range given by the measurement uncertainty. Furthermore, the broadband radiative simulations estimated a net (solar plus thermal infrared) radiative forcing of the subvisible midlevel ice cloud of −0.4 W m−2 (−3.2 W m−2 in the solar and +2.8 W m−2 in the thermal infrared wavelength range).

scholarly journals Microphysical and optical properties of Arctic mixed-phase clouds. The 9 April 2007 case study.

2009 ◽  
Vol 9 (17) ◽  
pp. 6581-6595 ◽  
Author(s):  
J.-F. Gayet ◽  
G. Mioche ◽  
A. Dörnbrack ◽  
A. Ehrlich ◽  
A. Lampert ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Liquid Water ◽  
In Situ Measurements ◽  
Mixed Phase ◽  
Ice Crystals ◽  
The Arctic ◽  
Small Scale ◽  
Water Droplets ◽  
Tropospheric Aerosol

Abstract. Airborne measurements in Arctic boundary-layer stratocumulus were carried out near Spitsbergen on 9 April 2007 during the Arctic Study of Tropospheric Aerosol, Clouds and Radiation (ASTAR) campaign. A unique set of co-located observations is used to describe the cloud properties, including detailed in situ cloud microphysical and radiation measurements along with airborne and co-located spaceborne remote sensing data (CALIPSO lidar and CloudSat radar). CALIPSO profiles indicate cloud top levels at temperature between −24°C and −21°C. In situ measurements confirm that the cloud-top lidar attenuated backscatter signal along the aircraft trajectory is linked with the presence of liquid water, a common feature observed in Arctic mixed-phase stratocumulus clouds. A low concentration of large ice crystals is also observed up to the cloud top resulting in significant CloudSat radar echoes. Since the ratio of the extinction of liquid water droplets to ice crystals is high, broadband radiative effects near the cloud top are mostly dominated by water droplets. CloudSat observations and in situ measurements reveal high reflectivity factors (up to 15 dBZ) and precipitation rates (1 mm h−1). This feature results from efficient ice growth processes. About 25% of the theoretically available liquid water is converted into ice water with large precipitating ice crystals. Using an estimate of mean cloud cover, a considerable value of 106 m3 h−1 of fresh water could be settled over the Greenland sea pool. European Centre for Medium-Range Weather Forecast (ECMWF) operational analyses reproduces the boundary layer height variation along the flight track. However, small-scale features in the observed cloud field cannot be resolved by ECMWF analysis. Furthermore, ECMWF's diagnostic partitioning of the condensed water into ice and liquid reveals serious shortcomings for Arctic mixed-phased clouds. Too much ice is modelled.

STORM ICE OIL WIND WAVE WATCH SYSTEM (SIOWS): WEB GIS APPLICATION FOR MONITORING THE ARCTIC

2017 ◽  
Author(s):  
Alexander Myasoedov ◽  
Alexander Myasoedov ◽  
Sergey Azarov ◽  
Sergey Azarov ◽  
Ekaterina Balashova ◽  
...  
Keyword(s):  
Satellite Data ◽  
Wind Wave ◽  
Arctic Region ◽  
Web Gis ◽  
The Arctic ◽  
Flexible Tool ◽  
In Situ Data ◽  
Current State ◽  
Watch System

Working with satellite data, has long been an issue for users which has often prevented from a wider use of these data because of Volume, Access, Format and Data Combination. The purpose of the Storm Ice Oil Wind Wave Watch System (SIOWS) developed at Satellite Oceanography Laboratory (SOLab) is to solve the main issues encountered with satellite data and to provide users with a fast and flexible tool to select and extract data within massive archives that match exactly its needs or interest improving the efficiency of the monitoring system of geophysical conditions in the Arctic. SIOWS - is a Web GIS, designed to display various satellite, model and in situ data, it uses developed at SOLab storing, processing and visualization technologies for operational and archived data. It allows synergistic analysis of both historical data and monitoring of the current state and dynamics of the "ocean-atmosphere-cryosphere" system in the Arctic region, as well as Arctic system forecasting based on thermodynamic models with satellite data assimilation.

In situ optical and microphysical properties of tropospheric aerosols in the Canadian High Arctic from 2016 to 2019

2021 ◽  
Vol 250 ◽  
pp. 118254
Author(s):  
Andy Vicente-Luis ◽  
Samantha Tremblay ◽  
Joelle Dionne ◽  
Rachel Y.-W. Chang ◽  
Pierre F. Fogal ◽  
...  
Keyword(s):  
High Arctic ◽  
Canadian High Arctic ◽  
Microphysical Properties ◽  
Tropospheric Aerosols

scholarly journals International Arctic Systems for Observing the Atmosphere: An International Polar Year Legacy Consortium

2016 ◽  
Vol 97 (6) ◽  
pp. 1033-1056 ◽  
Author(s):  
Taneil Uttal ◽  
Sandra Starkweather ◽  
James R. Drummond ◽  
Timo Vihma ◽  
Alexander P. Makshtas ◽  
...  
Keyword(s):  
United States ◽  
The United States ◽  
Satellite Observations ◽  
The Arctic ◽  
International Polar Year ◽  
Network Measurements ◽  
International Polar ◽  
In Situ Observations ◽  
Arctic Atmosphere

Abstract International Arctic Systems for Observing the Atmosphere (IASOA) activities and partnerships were initiated as a part of the 2007–09 International Polar Year (IPY) and are expected to continue for many decades as a legacy program. The IASOA focus is on coordinating intensive measurements of the Arctic atmosphere collected in the United States, Canada, Russia, Norway, Finland, and Greenland to create synthesis science that leads to an understanding of why and not just how the Arctic atmosphere is evolving. The IASOA premise is that there are limitations with Arctic modeling and satellite observations that can only be addressed with boots-on-the-ground, in situ observations and that the potential of combining individual station and network measurements into an integrated observing system is tremendous. The IASOA vision is that by further integrating with other network observing programs focusing on hydrology, glaciology, oceanography, terrestrial, and biological systems it will be possible to understand the mechanisms of the entire Arctic system, perhaps well enough for humans to mitigate undesirable variations and adapt to inevitable change.

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