Optical Scattering and Microphysical Properties of Subvisual Cirrus Clouds, and Climatic Implications

Sassen, Kenneth; Griffin, Michael K.; Dodd, Gregory C.

doi:10.1175/1520-0450(1989)028<0091:osampo>2.0.co;2

Cited by 139 publications

(107 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Here we argue that infrared (IR) limb sounding from space provides an alternative measurement technique of high sensitivity for the detection of optically thin clouds (Mergenthaler et al, 1999;Massie et al, 2007;Griessbach et al, 2014), subvisible cirrus (SVC) defined by the extinction range 2 × 10 −4 -2 × 10 −2 km −1 (Sassen et al, 1989), or the even thinner ultra-thin tropical cirrus (UTTC) Luo et al, 2003). The IR limb sounder detection sensitivity for clouds is in the range of spaceborne lidar measurements (Höpfner et al, 2009;Spang et al, 2012).…”

Section: R Spang Et Al: Satellite Observations Of Cirrus Clouds In mentioning

confidence: 99%

Satellite observations of cirrus clouds in the Northern Hemisphere lowermost stratosphere

Spang¹,

Günther²,

Riese³

et al. 2015

Atmos. Chem. Phys.

View full text Add to dashboard Cite

Abstract.Here we present observations of the Cryogenic Infrared Spectrometers and Telescopes for the Atmosphere (CRISTA) of cirrus cloud and water vapour in August 1997 in the upper troposphere and lower stratosphere (UTLS). The observations indicate a considerable flux of moisture from the upper tropical troposphere into the extratropical lowermost stratosphere (LMS), resulting in the occurrence of highaltitude optically thin cirrus clouds in the LMS.The locations of the LMS cloud events observed by CRISTA are consistent with the tropopause height determined from coinciding radiosonde data. For a hemispheric analysis in tropopause relative coordinates an improved tropopause determination has been applied to the European Centre for Medium-Range Weather Forecasts (ECMWF) temperature profiles. We found that a significant fraction of the cloud occurrences in the tropopause region are located in the LMS, even if a conservative overestimate of the cloud top height (CTH) determination by CRISTA of 500 m is assumed. The results show rather high occurrence frequencies ( ∼ 5 %) up to high northern latitudes (70 • N) and altitudes well above the tropopause (> 500 m at ∼ 350 K and above) in large areas at mid-and high latitudes.Comparisons with model runs of the Chemical Lagrangian Model of the Stratosphere (CLaMS) over the CRISTA period show a reasonable consistency in the retrieved cloud pattern. For this purpose a limb ray tracing approach was applied through the 3-D model fields to obtain integrated measurement information through the atmosphere along the limb path of the instrument. The simplified cirrus scheme implemented in CLaMS seems to cause a systematic underestimation in the CTH occurrence frequencies in the LMS with respect to the observations. The observations together with the model results demonstrate the importance of isentropic, quasi-horizontal transport of water vapour from the subtropics and the potential for the occurrence of cirrus clouds in the lowermost stratosphere and tropopause region.

show abstract

Section: R Spang Et Al: Satellite Observations Of Cirrus Clouds In mentioning

confidence: 99%

Satellite observations of cirrus clouds in the Northern Hemisphere lowermost stratosphere

Spang¹,

Günther²,

Riese³

et al. 2015

Atmos. Chem. Phys.

View full text Add to dashboard Cite

show abstract

“…Criterion (3)is a crude measure of optical depth; if it is met, whatever clouds are present are too thin to be detected by nadir sounders. Note here that the use of the term "subvisible cirrus" is avoided, since that term implies a maximum optical depth of 0.03 [Sassen et al, 1989], a quantity that cannot be unambiguously determined from the available data. With few exceptions, the aircraft flew in nearly cloud free zones (essentially by design in order to allow the lidar instruments to make stratospheric observations).…”

Section: Observationsmentioning

confidence: 99%

Aircraft observations of thin cirrus clouds near the tropical tropopause

Pfister¹,

Selkirk²,

Jensen³

et al. 2001

J. Geophys. Res.

129

170

View full text Add to dashboard Cite

show abstract

“…Subvisible cirrus (SVC), defined as an ice cloud with an optical depth t below 0.03 [Sassen et al, 1989], has recently been reported to be abundant not only in the tropics, but also in the midlatitudes. Satellite data suggest a slightly higher occurrence frequency in the northern hemisphere compared to the southern hemisphere [Wang et al, 1996].…”

Section: Introductionmentioning

confidence: 99%

LIDAR measurements of cirrus clouds in the northern and southern midlatitudes during INCA (55°N, 53°S): A comparative study

Immler

Schrems

2002

Geophysical Research Letters

View full text Add to dashboard Cite

[1] Cirrus clouds have been probed at two locations in the midlatitudes of the southern (SH) and northern hemisphere (NH) with a Mobile Raman Aerosol Lidar (MARL) as part of the European INCA field experiments in 2000. MARL offers the opportunity to observe visible and subvisible clouds and to determine the optical depth t in a range from below 10 À3 up to 3. Despite different synoptic conditions we find at both locations similar macrophysical cloud properties, like mean base and top temperature among others. The frequencies of the optical depth show a characteristic distribution with a high share of subvisible clouds at both locations. While thin haze layers are frequently detected in the NH alone, we find highly depolarizing cirrus clouds only in the SH. These differences indicate that different cirrus properties and formation mechanisms are present at the two sites.

show abstract

Optical Scattering and Microphysical Properties of Subvisual Cirrus Clouds, and Climatic Implications

Cited by 139 publications

References 0 publications

Satellite observations of cirrus clouds in the Northern Hemisphere lowermost stratosphere

Satellite observations of cirrus clouds in the Northern Hemisphere lowermost stratosphere

Aircraft observations of thin cirrus clouds near the tropical tropopause

LIDAR measurements of cirrus clouds in the northern and southern midlatitudes during INCA (55°N, 53°S): A comparative study

Contact Info

Product

Resources

About