scholarly journals Numerical simulations of the three-dimensional distribution of polar mesospheric clouds and comparisons with Cloud Imaging and Particle Size (CIPS) experiment and the Solar Occultation For Ice Experiment (SOFIE) observations

2010 ◽  
Vol 115 (D10) ◽  
Author(s):  
C. G. Bardeen ◽  
O. B. Toon ◽  
E. J. Jensen ◽  
M. E. Hervig ◽  
C. E. Randall ◽  
...  
Keyword(s):  
Particle Size ◽  
Numerical Simulations ◽  
Three Dimensional ◽  
Polar Mesospheric Clouds ◽  
Solar Occultation ◽  
Dimensional Distribution ◽  
Mesospheric Clouds

scholarly journals Relationships between polar mesospheric clouds, temperature, and water vapor from Solar Occultation for Ice Experiment (SOFIE) observations

2009 ◽  
Vol 114 (D20) ◽  
Author(s):  
Mark E. Hervig ◽  
Michael H. Stevens ◽  
Larry L. Gordley ◽  
Lance E. Deaver ◽  
James M. Russell ◽  
...  
Keyword(s):  
Water Vapor ◽  
Polar Mesospheric Clouds ◽  
Solar Occultation ◽  
Mesospheric Clouds

scholarly journals Seasonal Variations of Volcanic Ash and Aerosol Emissions around Sakurajima Detected by Two Lidars

Atmosphere ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 326
Author(s):  
Atsushi Shimizu ◽  
Masato Iguchi ◽  
Haruhisa Nakamichi
Keyword(s):  
Particle Size ◽  
Extinction Coefficient ◽  
Volcanic Ash ◽  
Surface Wind ◽  
Three Dimensional ◽  
Japan Meteorological Agency ◽  
Extinction Coefficients ◽  
Ash Fall ◽  
Dimensional Distribution ◽  
Aerosol Emissions

Two polarization-sensitive lidars were operated continuously to monitor the three-dimensional distribution of small volcanic ash particles around Sakurajima volcano, Kagoshima, Japan. Here, we estimated monthly averaged extinction coefficients of particles between the lidar equipment and the vent and compared our results with monthly records of volcanic activity reported by the Japan Meteorological Agency, namely the numbers of eruptions and explosions, the density of ash fall, and the number of days on which ash fall was observed at the Kagoshima observatory. Elevated extinction coefficients were observed when the surface wind direction was toward the lidar. Peaks in extinction coefficient did not always coincide with peaks in ash fall density, and these differences likely indicate differences in particle size.

scholarly journals Concentric gravity waves in polar mesospheric clouds from the Cloud Imaging and Particle Size experiment

2014 ◽  
Vol 119 (9) ◽  
pp. 5115-5127 ◽  
Author(s):  
Jia Yue ◽  
Brentha Thurairajah ◽  
Lars Hoffmann ◽  
Joan Alexander ◽  
Amal Chandran ◽  
...  
Keyword(s):  
Particle Size ◽  
Gravity Waves ◽  
Polar Mesospheric Clouds ◽  
Mesospheric Clouds

scholarly journals Common volume satellite studies of polar mesospheric clouds with Odin/OSIRIS tomography and AIM/CIPS nadir imaging

2019 ◽  
Vol 19 (19) ◽  
pp. 12455-12475 ◽  
Author(s):  
Lina Broman ◽  
Susanne Benze ◽  
Jörg Gumbel ◽  
Ole Martin Christensen ◽  
Cora E. Randall
Keyword(s):  
Particle Size ◽  
Correlation Coefficient ◽  
Vertical Integration ◽  
Function Analysis ◽  
Scattering Coefficient ◽  
Cloud Albedo ◽  
Polar Mesospheric Clouds ◽  
Cloud Properties ◽  
Error Characterization ◽  
Mesospheric Clouds

Abstract. Two important approaches for satellite studies of polar mesospheric clouds (PMCs) are nadir measurements adapting phase function analysis and limb measurements adapting spectroscopic analysis. Combining both approaches enables new studies of cloud structures and microphysical processes but is complicated by differences in scattering conditions, observation geometry and sensitivity. In this study, we compare common volume PMC observations from the nadir-viewing Cloud Imaging and Particle Size (CIPS) instrument on the Aeronomy of Ice in the Mesosphere (AIM) satellite and a special set of tomographic limb observations from the Optical Spectrograph and InfraRed Imager System (OSIRIS) on the Odin satellite performed over 18 d for the years 2010 and 2011 and the latitude range 78 to 80∘ N. While CIPS provides preeminent horizontal resolution, the OSIRIS tomographic analysis provides combined horizontal and vertical PMC information. This first direct comparison is an important step towards co-analysing CIPS and OSIRIS data, aiming at unprecedented insights into horizontal and vertical cloud processes. Important scientific questions on how the PMC life cycle is affected by changes in humidity and temperature due to atmospheric gravity waves, planetary waves and tides can be addressed by combining PMC observations in multiple dimensions. Two- and three-dimensional cloud structures simultaneously observed by CIPS and tomographic OSIRIS provide a useful tool for studies of cloud growth and sublimation. Moreover, the combined CIPS/tomographic OSIRIS dataset can be used for studies of even more fundamental character, such as the question of the assumption of the PMC particle size distribution. We perform the first thorough error characterization of OSIRIS tomographic cloud brightness and cloud ice water content (IWC). We establish a consistent method for comparing cloud properties from limb tomography and nadir observations, accounting for differences in scattering conditions, resolution and sensitivity. Based on an extensive common volume and a temporal coincidence criterion of only 5 min, our method enables a detailed comparison of PMC regions of varying brightness and IWC. However, since the dataset is limited to 18 d of observations this study does not include a comparison of cloud frequency. The cloud properties of the OSIRIS tomographic dataset are vertically resolved, while the cloud properties of the CIPS dataset is vertically integrated. To make these different quantities comparable, the OSIRIS tomographic cloud properties cloud scattering coefficient and ice mass density (IMD) have been integrated over the vertical extent of the cloud to form cloud albedo and IWC of the same quantity as CIPS cloud products. We find that the OSIRIS albedo (obtained from the vertical integration of the primary OSIRIS tomography product, cloud scattering coefficient) shows very good agreement with the primary CIPS product, cloud albedo, with a correlation coefficient of 0.96. However, OSIRIS systematically reports brighter clouds than CIPS and the bias between the instruments (OSIRIS – CIPS) is 3.4×10-6 sr−1 (±2.9×10-6 sr−1) on average. The OSIRIS tomography IWC (obtained from the vertical integration of IMD) agrees well with the CIPS IWC, with a correlation coefficient of 0.91. However, the IWC reported by OSIRIS is lower than CIPS, and we quantify the bias to −22 g km−2 (±14 g km−2) on average.

Comparing nadir and limb observations of polar mesospheric clouds: The effect of the assumed particle size distribution

2015 ◽  
Vol 127 ◽  
pp. 51-65 ◽  
Author(s):  
Scott M. Bailey ◽  
Gary E. Thomas ◽  
Mark E. Hervig ◽  
Jerry D. Lumpe ◽  
Cora E. Randall ◽  
...  
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Polar Mesospheric Clouds ◽  
Mesospheric Clouds

scholarly journals An analysis of POAM II solar occultation observations of polar mesospheric clouds in the southern hemisphere

1997 ◽  
Vol 102 (D2) ◽  
pp. 1971-1981 ◽  
Author(s):  
D. J. Debrestian ◽  
J. D. Lumpe ◽  
E. P. Shettle ◽  
R. M. Bevilacqua ◽  
J. J. Olivero ◽  
...  
Keyword(s):  
Southern Hemisphere ◽  
Polar Mesospheric Clouds ◽  
Solar Occultation ◽  
Mesospheric Clouds

scholarly journals Albedo-Ice Regression method for determining ice water content of polar mesospheric clouds using ultraviolet observations from space

2019 ◽  
Vol 12 (3) ◽  
pp. 1755-1766 ◽  
Author(s):  
Gary E. Thomas ◽  
Jerry Lumpe ◽  
Charles Bardeen ◽  
Cora E. Randall
Keyword(s):  
Particle Size ◽  
Water Content ◽  
Average Error ◽  
Polar Mesospheric Clouds ◽  
Mode Of Operation ◽  
Ice Water Content ◽  
Mesospheric Clouds ◽  
Using Data ◽  
Ultraviolet Observations ◽  
Ice Water

Abstract. High spatial resolution images of polar mesospheric clouds (PMCs) from a camera array on board the Aeronomy of Ice in the Mesosphere (AIM) satellite have been obtained since 2007. The Cloud Imaging and Particle Size Experiment (CIPS) detects scattered ultraviolet (UV) radiance at a variety of scattering angles, allowing the scattering phase function to be measured for every image pixel. With well-established scattering theory, the mean particle size and ice water content (IWC) are derived. In the nominal mode of operation, approximately seven scattering angles are measured per cloud pixel. However, because of a change in the orbital geometry in 2016, a new mode of operation was implemented such that one scattering angle, or at most two, per pixel are now available. Thus particle size and IWC can no longer be derived from the standard CIPS algorithm. The Albedo-Ice Regression (AIR) method was devised to overcome this obstacle. Using data from both a microphysical model and from CIPS in its normal mode, we show that the AIR method provides sufficiently accurate average IWC so that PMC IWC can be retrieved from CIPS data into the future, even when albedo is not measured at multiple scattering angles. We also show from the model that 265 nm UV scattering is sensitive only to ice particle sizes greater than about 20–25 nm in (effective) radius and that the operational CIPS algorithm has an average error in retrieving IWC of -13±17 %.

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