- National weather services (incl. COPERNICUS/MACC): calibrated attenuated
backscatter profiles to evaluate NWP models (through forward operators); Cloud
base height for NWP evaluation and weather monitoring.
- Agencies in charge of atmospheric surveillance for air traffic: occurrence, height and mass concentrations of ash layers; diagnostic and short-term forecast of fog and other low visibility events.
- Agencies in charge of Air Quality monitoring: boundary layer height; freetropospheric aerosol transport.
- Networks in charge of GHG monitoring: boundary layer height to quantify GHG
- EUMETSAT: European-wide validation of cloud-base height and fog
- Renewable energy industry: Photovoltaic ReN – cloud/fog fraction and evolution for nowcasting applications (combined with geostationary satellite); Concentrated solar power: aerosol vertical distribution; Wind ReN – wind profiles from Doppler Lidars.
|Title:||Dust storm from Syria- a potential new aerosol source in the E. Mediterranean- A ceilometer and synoptic study|
|Authors:||Alpert, Pinhas; Egert, Smadar; Uzan, Leenes|
On 7 Sep 2015 an unprecedented huge dust plume approached the SE Mediterranean basin from the northeast- Syria region. According to the Israeli meteorological service it is the first time in 75 years of measurements, that a dust storm reaches Israel early September, lasts several days and dust concentrations reach values 100 times the normal (1700µg/m3). Dust storms are normally monitored in the east Mediterranean using satellites and surface PM data. Obviously, these cannot show the vertical evolution of the dust including penetration, sinking and cleaning since vertical profiles are not available. High-resolution, micro Lidar Ceilometer network is gradually established in Israel. A few instruments of this network were already operational during the dust storm. The most crucial vertical information, monitored by these Ceilometers with 10m resolution vertically, every 16s, is analyzed. The difference in the cloud-layers allow the investigation of the high altitude of 1000m dust penetration, its sinking into the complex structured 250-500m mixed layer and the gradual 3D cleaning. This finding contradicts the conventional understanding that cleaning is due to gradual descent and shows not only the vertical fluctuation during the entire event but also the vertical rise to 2000m at the end of the event. The vertical information showed that the actual event period duration was 7 days, compared to only 90 hours based on traditional detectors. Is it a new dust source in the E. Mediterranean-long and short term trends?
The International Commission on Clouds and Precipitation (ICCP) is a Commission of the International Association of Meteorology and Atmospheric Sciences (IAMAS)
The IAMAS is one of the associations of the International Union of Geodesy and Geophysics (IUGG)
The ICCP holds a conference every 4 years. The last conference was at Manchester University in 2016, The next is due in 2020.
Typical subjects in calls for papers are theoretical, observational and numerical modelling studies of cloud and precipitation physics, cloud chemistry and cloud dynamics.
For instance the following subjects are commonly covered at the conferences
- Basic cloud and precipitation physics
- Warm boundary layer clouds
- Convective clouds (including cloud electrification)
- Mixed phase clouds (including Arctic/Antarctic stratus, mid-level clouds)
- Cirrus clouds
- Orographic clouds
- Fog and fog layers
- Mesoscale cloud systems (including severe storms)
- Tropical clouds
- Southern Ocean clouds
- Polar stratospheric clouds and noctilucent clouds
- Aerosol-cloud-precipitation-interactions and processing
- Clouds and climate (including radiative properties of clouds)
- Ice nuclei and cloud condensation nuclei
- Cloud and precipitation chemistry
- Measurement techniques (of cloud and precipitation properties) and uncertainties
- Applications of cloud and precipitation physics
There are very few Ceilometer manufacturers in the world. Ceilometers have advanced technical requirements and the cost of development is high. In the production phase ceilometers are assembled from many special optical and electronic parts. During testing they require specialised pulsed laser power meters, spectrophotometers and advanced electronic test equipment, together with a cloudy climate to enable regular testing and continuous product improvement.
Sensor Range Class
- 12500 ft range, ( 3800m) an example of which was the original CT12K. This range is now encompassed by the 25,000 ft range sensors.
- 25,000 ft range ( 7600m) These are the main sensors on the market since in the main application there is little operational need to go beyond even 12500 ft. These sensors also find application in Planetary Boundary Layer ( PBL) studies.
- 50,000 ft range (15,200m) Special instruments that find more application in volcanic ash warning in aviation and upper atmosphere studies in atmospheric science. Although in theory only requiring a modest increase in signal to noise ratio, the cloud species above 20,000 ft are most often comprised of ice crystals and have much lower volume back-scatter coefficients than water cloud so the reliable detection of thin layers of cirrus cloud becomes very difficult while maintaining the laser eye safety mandate. Ceilometers in this range generally achieve the necessary signal to noise ratio improvement by a range of techniques including increasing laser pulse energy ( while still remaining eye safe ), using a different laser wavelength, and or reducing the telescope field of view and laser beam divergence.
25,000 ft range for Aviation and PBL studies
CL31 : http://www.vaisala.com/en/products/ceilometers/Pages/default.aspx
8200-CHS : http://www.ceilometers.com/
CS135 : https://www.campbellsci.com.au/cs135
50000 ft Range for Atmospheric Science
CL51 : http://www.vaisala.com/en/products/ceilometers/Pages/default.aspx
A good source of atmospheric sensing and measurement research and applications for Ceilometers among other techniques can be reviewed here Atmospheric Measurement Techniques.
This site contains a listing of many research papers and a discussion forum. It is a European based site.
The current link for ceilometer based searches is here
How much do you know about Clouds?
This quiz appeared in an Australian Newspaper.