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.

A Mechanism for the Effect of Tropospheric Jet Structure on the Annular Mode–Like Response to Stratospheric Forcing

2012 ◽  
Vol 69 (7) ◽  
pp. 2152-2170 ◽  
Author(s):  
Isla R. Simpson ◽  
Michael Blackburn ◽  
Joanna D. Haigh
Keyword(s):  
Momentum Flux ◽  
General Circulation ◽  
General Circulation Models ◽  
Lower Latitude ◽  
Mean Flow ◽  
Zonal Winds ◽  
Feedback Strength ◽  
Poleward Shift ◽  
Climate Forcings ◽  
Jet Structure

Abstract For many climate forcings the dominant response of the extratropical circulation is a latitudinal shift of the tropospheric midlatitude jets. The magnitude of this response appears to depend on climatological jet latitude in general circulation models (GCMs): lower-latitude jets exhibit a larger shift. The reason for this latitude dependence is investigated for a particular forcing, heating of the equatorial stratosphere, which shifts the jet poleward. Spinup ensembles with a simplified GCM are used to examine the evolution of the response for five different jet structures. These differ in the latitude of the eddy-driven jet but have similar subtropical zonal winds. It is found that lower-latitude jets exhibit a larger response due to stronger tropospheric eddy–mean flow feedbacks. A dominant feedback responsible for enhancing the poleward shift is an enhanced equatorward refraction of the eddies, resulting in an increased momentum flux, poleward of the low-latitude critical line. The sensitivity of feedback strength to jet structure is associated with differences in the coherence of this behavior across the spectrum of eddy phase speeds. In the configurations used, the higher-latitude jets have a wider range of critical latitude locations. This reduces the coherence of the momentum flux anomalies associated with different phase speeds, with low phase speeds opposing the effect of high phase speeds. This suggests that, for a given subtropical zonal wind strength, the latitude of the eddy-driven jet affects the feedback through its influence on the width of the region of westerly winds and the range of critical latitudes on the equatorward flank of the jet.

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
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