Seasonal migration of cirrus clouds by using CALIOP observations

Nee, J. B.; Lu, Chih-Wen

doi:10.1007/s00703-020-00769-8

Cited by 2 publications

(2 citation statements)

References 52 publications

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“…The seasonal cycles of convective and non-convective cirrus described here are generally consistent with previous studies of cirrus clouds below 14 km-15 km (Sassen et al, 2008;Nee and Lu, 2021) and cirrus clouds above 14 km-15 km (Tseng and Fu, 2017;Nee and Lu, 2021) respectively. However, the significance here is that we are able to distinguish convective and non-convective cirrus from each other despite the overlapping in their vertical distributions (see between convective cirrus and convection, and between non-convective cirrus in the TTL and the temperature there.…”

Section: Seasonal Cyclessupporting

confidence: 91%

Tropical cirrus clouds of convective and non-convective origins

Huang

Dinh

2022

Preprint

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Abstract. The occurrence of cirrus clouds in the tropics (24 °S–24 °N) is analyzed using the 2007–2015 monthly data from the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) and the fifth generation reanalysis product (ERA5) of the European Centre for Medium-Range Weather Forecasts. In most cirrus clouds, the specific humidity (SPH) is larger than in cloud-free air and/or the temperature is smaller than in cloud-free air. Both positive SPH perturbations and negative temperature perturbations increase the relative humidity, resulting in favorable conditions for the formation and maintenance of clouds. The clouds in which there are positive SPH perturbations are considered to originate from convection. This is because, in the free troposphere, positive SPH anomalies are largely produced by the upward transport of moisture by convection followed by detrainment of the convective plumes. The remaining clouds that are not directly influenced by convection are driven by negative temperature perturbations. These temperature-driven clouds are formed and maintained in the cold phases of gravity waves and/or by the adiabatic cooling associated with the upwelling branch of the Brewer–Dobson circulation. Averaged over all altitudes of the tropical atmosphere, there are about three times more convective cirrus than non-convective ones. The level of maximum convective cirrus occurrence is at 14 km, i.e., the bottom of the tropical tropopause layer (TTL). Non-convective cirrus obtain their maximum frequency of occurrence at about 16 km, which is below the cold point tropopause (CPT). The seasonal cycle of convective cirrus is consistent with that of tropical convection, while the seasonal cycle of non-convective cirrus in the TTL is consistent with that of the CPT. There are two maxima in the frequency of occurrence of convective cirrus, one at around 10 °S in the austral summer, and the other at around 10 °N in the boreal summer. In contrast, non-convective cirrus occur most frequently near the equator in the boreal winter. The ice water content (IWC) in both convective and non-convective cirrus increases with increasing temperature (decreasing altitude). Thus, non-convective cirrus—which on average occur at lower temperatures (higher altitudes)—tend to have lower IWCs than convective cirrus.

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Section: Seasonal Cyclessupporting

confidence: 91%

Tropical cirrus clouds of convective and non-convective origins

Huang

Dinh

2022

Preprint

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“…In this research, we used MODIS (MOD09) adapted satellite recordings. These satellite recordings were adapted and cropped in shape format, covering the whole territory of Serbia [32][33][34][35][36]. The data on cloud frequencies had a resolution of 500 m. The most efficient method for estimating cloud cover is based on multispectral time series and surface reflectance.…”

Section: Datamentioning

confidence: 99%

Long Term Monitoring and Connection between Topography and Cloud Cover Distribution in Serbia

et al. 2021

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The use of weather satellite recordings has been growing rapidly over the last three decades. Determining the patterns between meteorological and topographical features is an important scientific job. Cloud cover analysis and properties can be of the utmost significance for potential cloud seeding. Here, the analysis of the cloud properties was conducted by means of Moderate Resolution Imaging Spectroradiometer (MODIS) satellite recordings. The resolution of used data was 1 km2 within the period of 30 years (1989–2019). This research showed moderate changing of cloudiness in the territory of Serbia with a high cloudiness in February, followed by cloudiness in January and November. For the past three decades, May has been the month with the highest cloudiness. The regions in the east and south-west, and particularly in the west, have a high absolute cloudiness, which is connected with the high elevation of the country. By means of long term monitoring, the whole territory of Serbia was analyzed for the first time, in terms of cloudiness. Apart from the statistical and numerical results obtained, this research showed a connection between relief and clouds, especially in the winter season. Linear regression MK (Mann–Kendall test) has proven this theory right, connecting high elevation sides with high absolute cloudiness through the year.

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Seasonal migration of cirrus clouds by using CALIOP observations

Cited by 2 publications

References 52 publications

Tropical cirrus clouds of convective and non-convective origins

Tropical cirrus clouds of convective and non-convective origins

Long Term Monitoring and Connection between Topography and Cloud Cover Distribution in Serbia

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