scholarly journals Life cycle of shallow marine cumulus clouds from geostationary satellite observations

2021 ◽  
Author(s):  
Torsten Seelig ◽  
Hartwig Deneke ◽  
Johannes Quaas ◽  
Matthias Tesche
Keyword(s):  
Life Cycle ◽  
Geostationary Satellite ◽  
Satellite Observations ◽  
Cumulus Clouds ◽  
Shallow Marine

Wolkenverfolgung: Vom Experiment zur Realität

2021 ◽  
Author(s):  
Torsten Seelig ◽  
Felix Müller ◽  
Matthias Tesche
Keyword(s):  
Experimental Investigation ◽  
Life Cycle ◽  
Momentum Flux ◽  
Geostationary Satellite ◽  
Satellite Observations ◽  
Inertial Waves ◽  
Mean Flow ◽  
Cumulus Clouds ◽  
Instability Waves ◽  
Shallow Marine

<p>Die Wolkenverfolgung ist die einzige Möglichkeit zur Beobachtung der zeitlichen Entwicklung von Wolken und zur Quantifizierung der Veränderung ihrer physikalischen Eigenschaften während ihrer Lebensdauer (Seelig et al., 2021). Der Schlüssel dazu sind zeitaufgelöste Messungen von Instrumenten an Bord geostationärer Satelliten. Experimente mit atmosphärenähnlicher Konfiguration treiben die Entwicklung von Messmethoden und Alghoritmen unter Laborbedingungen voran. Heutzutage ist es z.B. möglich zweidimensionale, zeitlich und räumlich hochaufgelöste Geschwindigkeitsfelder auf Basis der Verschiebung kleinster Partikel zu messen (Seelig and Harlander, 2015; Seelig et al., 2018). Die Methodik der Partikelgeschwindigkeitsmessung dient als Anfangsbedingung zum Verfolgen dieser Partikel und kann auf troposphärische Wolken angewendet werden. Diese Präsentation stellt die Analogie von Experiment zur Realität vor, beschreibt das Verfahren der Partikelgeschwindigkeitsmessung und die Anwendung auf Daten geostationärer Satelliten.</p> <p><strong>Literatur:</strong></p> <p>Seelig, T., Deneke, H., Quaas, J., and Tesche, M.: Life cycle of shallow marine cumulus clouds from geostationary satellite observations, J. Geophys. Res.: Atmos., 126(22), e2021JD035577, https://doi.org/10.1029/2021JD035577, 2021.</p> <p>Seelig, T., Harlander, U., and Gellert, M.: Experimental investigation of stratorotational instability using a thermally stratified system: instability, waves and associated momentum flux, Geophys. Astrophys. Fluid Dyn., 112, 239-264, https://doi.org/10.1080/03091929.2018.1488971, 2018.</p> <p>Seelig, T. and Harlander, U.: Can zonally symmetric inertial waves drive an oscillating zonal mean flow?, Geophys. Astrophys. Fluid Dyn., 109, 541-566, https://doi.org/10.1080/03091929.2015.1094064, 2015.</p>

scholarly journals Inverting the East Asian Dust Emission Fluxes Using the Ensemble Kalman Smoother and Himawari-8 AODs: A Case Study with WRF-Chem v3.5.1

Atmosphere ◽  
2019 ◽  
Vol 10 (9) ◽  
pp. 543
Author(s):  
Dai ◽  
Cheng ◽  
Goto ◽  
Schutgens ◽  
Kikuchi ◽  
...  
Keyword(s):  
Dust Emission ◽  
Asian Dust ◽  
Geostationary Satellite ◽  
Satellite Observations ◽  
Dust Emissions ◽  
Total Dust ◽  
Kalman Smoother ◽  
Independent Observations ◽  
Moderate Resolution Imaging Spectroradiometer ◽  
Horizontal And Vertical Distributions

We present the inversions (back-calculations or optimizations) of dust emissions for a severe winter dust event over East Asia in November 2016. The inversion system based on a fixed-lag ensemble Kalman smoother is newly implemented in the Weather Research and Forecasting model and is coupled with Chemistry (WRF-Chem). The assimilated observations are the hourly aerosol optical depths (AODs) from the next-generation geostationary satellite Himawari-8. The posterior total dust emissions (2.59 Tg) for this event are 3.8 times higher than the priori total dust emissions (0.68 Tg) during 25–27 November 2016. The net result is that the simulated aerosol horizontal and vertical distributions are both in better agreement with the assimilated Himawari-8 observations and independent observations from the ground-based AErosol RObotic NETwork (AERONET), the satellite-based Moderate Resolution Imaging Spectroradiometer (MODIS) and the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO). The developed emission inversion approach, combined with the geostationary satellite observations, can be very helpful for properly estimating the Asian dust emissions.

Geostationary satellite observations of dynamic phytoplankton photophysiology

2014 ◽  
Vol 41 (14) ◽  
pp. 5052-5059 ◽  
Author(s):  
Robert T. O'Malley ◽  
Michael J. Behrenfeld ◽  
Toby K. Westberry ◽  
Allen J. Milligan ◽  
Shaoling Shang ◽  
...  
Keyword(s):  
Geostationary Satellite ◽  
Satellite Observations

scholarly journals Aerosols, clouds, and precipitation in the North Atlantic trades observed during the Barbados aerosol cloud experiment – Part 1: Distributions and variability

2016 ◽  
Vol 16 (13) ◽  
pp. 8643-8666 ◽  
Author(s):  
Eunsil Jung ◽  
Bruce A. Albrecht ◽  
Graham Feingold ◽  
Haflidi H. Jonsson ◽  
Patrick Chuang ◽  
...  
Keyword(s):  
Boundary Layer ◽  
North Atlantic ◽  
Cloud Base ◽  
Cumulus Clouds ◽  
Air Masses ◽  
Shallow Marine ◽  
Cloud Radar ◽  
Aerosol Cloud ◽  
The North ◽  
The North Atlantic

Abstract. Shallow marine cumulus clouds are by far the most frequently observed cloud type over the Earth's oceans; but they are poorly understood and have not been investigated as extensively as stratocumulus clouds. This study describes and discusses the properties and variations of aerosol, cloud, and precipitation associated with shallow marine cumulus clouds observed in the North Atlantic trades during a field campaign (Barbados Aerosol Cloud Experiment- BACEX, March–April 2010), which took place off Barbados where African dust periodically affects the region. The principal observing platform was the Center for Interdisciplinary Remotely Piloted Aircraft Studies (CIRPAS) Twin Otter (TO) research aircraft, which was equipped with standard meteorological instruments, a zenith pointing cloud radar and probes that measured aerosol, cloud, and precipitation characteristics.The temporal variation and vertical distribution of aerosols observed from the 15 flights, which included the most intense African dust event during all of 2010 in Barbados, showed a wide range of aerosol conditions. During dusty periods, aerosol concentrations increased substantially in the size range between 0.5 and 10 µm (diameter), particles that are large enough to be effective giant cloud condensation nuclei (CCN). The 10-day back trajectories showed three distinct air masses with distinct vertical structures associated with air masses originating in the Atlantic (typical maritime air mass with relatively low aerosol concentrations in the marine boundary layer), Africa (Saharan air layer), and mid-latitudes (continental pollution plumes). Despite the large differences in the total mass loading and the origin of the aerosols, the overall shapes of the aerosol particle size distributions were consistent, with the exception of the transition period.The TO was able to sample many clouds at various phases of growth. Maximum cloud depth observed was less than ∼ 3 km, while most clouds were less than 1 km deep. Clouds tend to precipitate when the cloud is thicker than 500–600 m. Distributions of cloud field characteristics (depth, radar reflectivity, Doppler velocity, precipitation) were well identified in the reflectivity–velocity diagram from the cloud radar observations. Two types of precipitation features were observed for shallow marine cumulus clouds that may impact boundary layer differently: first, a classic cloud-base precipitation where precipitation shafts were observed to emanate from the cloud base; second, cloud-top precipitation where precipitation shafts emanated mainly near the cloud tops, sometimes accompanied by precipitation near the cloud base. The second type of precipitation was more frequently observed during the experiment. Only 42–44 % of the clouds sampled were non-precipitating throughout the entire cloud layer and the rest of the clouds showed precipitation somewhere in the cloud, predominantly closer to the cloud top.

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