On the reliability of geostationary satellite observations for diagnosing indirect aerosol effects

Daniel Merk; Hartwig Deneke; Bernhard Pospichal; Patric Seifert

doi:10.1117/12.2194897

16 October 2015 On the reliability of geostationary satellite observations for diagnosing indirect aerosol effects

Daniel Merk, Hartwig Deneke, Bernhard Pospichal, Patric Seifert

Proceedings Volume 9640, Remote Sensing of Clouds and the Atmosphere XX; 96400D (2015) https://doi.org/10.1117/12.2194897
Event: SPIE Remote Sensing, 2015, Toulouse, France

Abstract

Aerosol indirect effects are poorly understand and constitute a highly uncertain anthropogenic forcing of climate change. The interaction of aerosols with clouds together with entrainment and turbulent mixing processes modulate cloud microphysics and radiative effects. In the current study we present preliminary results to diagnose indirect aerosol effects from the synergy of geostationary satellite observations, surface observations and MACC aerosol analysis. We examine if the sub-adiabatic factor - representative for entrainment - can be obtained from the combination of passive-satellite observations with ground-based cloud base height from a ceilometer network. Therefore the uncertainty of the sub-adiabatic factor due to its required input parameters, the cloud geometrical thickness and liquid water path, is explored. We use a two year dataset from SEVIRI and compare it to the LACROS supersite at Leipzig, Germany. We find that the comparison of satellite-retrieved cloud top heights shows a RMSD of 1100 m and the liquid water path of 75 gm^-2, which are too large to provide a meaningful estimate of the instantaneous sub-adiabtic factor. Linking the cloud microphysical properties from passive satellites with aerosol properties obtained from MACC, we investigate the Twomey hypothesis, namely that smaller droplets and a higher cloud droplet number concentration result from higher aerosol load for a given liquid water path (positive change). A positive relative change is obtained for aerosol optical depth and the sulphate mass integrated from the surface to the cloud top. In contrast, a negative relative change is however found for sea salt.

Citation Download Citation

Daniel Merk, Hartwig Deneke, Bernhard Pospichal, and Patric Seifert "On the reliability of geostationary satellite observations for diagnosing indirect aerosol effects", Proc. SPIE 9640, Remote Sensing of Clouds and the Atmosphere XX, 96400D (16 October 2015); https://doi.org/10.1117/12.2194897

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available

Members: $17.00

Non-members: $21.00 ADD TO CART

PROCEEDINGS
8 PAGES

DOWNLOAD PAPER SAVE TO MY LIBRARY

GET CITATION

RIGHTS & PERMISSIONS

Get copyright permission Get copyright permission on Copyright Marketplace

KEYWORDS

Clouds

Aerosols

Satellites

Liquids

Earth observing sensors

MODIS

Atmospheric modeling

Show All Keywords

Keywords/Phrases

Search In:

Publication Years