Images

Cloud Seeding Descriptions:

All photos were taken in Monclova, Coahuila for the PARC project (Program for the Augmentation of Rainfall in Coahuila). Credit should be given to the National Center for Atmospheric Research.

"Seeding": Seeding with hygroscopic flares over Monclova, Coahuila Mexico.

"Burning Flares": Burning hygroscopic flares to seed a cloud over Monclova, Coahuila.

"Install Flares": Researchers install hygroscopic flares onto a Piper Cheyenne twin-engine turboprop airplane prior to cloud seeding. The gentleman are,

On the left: Bruno Garcia, a professor at Universidad Autonoma Agraria Antonio Narro (UAAAN).
In the middle: Francisco Covarrubias, an administrator at Secretaria de Fomento Agropecuario State of Coahuila.
On the right: Jeff Lund from Weather Modification, Inc. (WMI)

"Window Flare": View of hygroscopic flares burning from the window of the PARC research aircraft.

"Aircraft": A photo of the aircraft used in the project; it is a Piper Cheyenne twin-engine turboprop airplane.

Turbulence Image Descriptions

Reference: Kane, T.L., B.G. Brown, and R. Sharman, 1999: A Preliminary Climatology of Upper Level Turbulence Reports. Preprints, 8th Conf. on Aviation, Range, and Aerospace Meteorology, 10-15 January, Dallas, American Meteorological Society, 363-367.

Click here for an abstract.

Description: Figure POS shows the percent of all turbulence (i.e. positive plus negative) reports which are positive for the winter months (November through March) of 1992 through 2000. This analysis is an attempt to remove reporting biases (e.g. related to flight paths or report solicitation), in an effort to answer the question, "How often does turbulence occur?" The POS figure indicates that the Rocky Mountain region, the Pacific Northwest, and the Gulf Coast have a high percentage of positive PIREPs.

The proportion of Moderate or Greater (MOG) out of all positive PIREPs during the same time period is shown in Figure MOG. This statistic gives information about the relative severity of turbulence in different regions. The Rocky Mountain region and Gulf Coast show a high percentage of MOG PIREPs, i.e. turbulence is both frequent and severe. Interestingly, the Pacific Northwest has a high percentage of positive turbulence, but a low percentage of MOG turbulence. This comparison implies that turbulence in that region is frequent, but rarely severe.

Seasonal (i.e. three-monthly) analyses have been undertaken for the period from July 1992 through June 2000. The figures show the seasonal proportions of Moderate or Greater (MOG) to positive PIREPs over 20,000 feet. Each map is based on data collected over an 8-year period. The maps for fall (October -December), winter (January - March), and spring (April - June) all suggest a relationship between topography and a high proportion of MOG/positive PIREPs. During these seasons, high proportions are evident along the Rocky Mountains, the Sierra Nevadas and the Cascades. The proportions along the Appalachians are also higher than in the surrounding areas, although not as high as near other mountain ranges. In fall and winter, the Gulf Coast also shows a high proportion of MOG/positive PIREPs. However, in spring and summer, high numbers appear less frequently along the Gulf Coast. The summer seasons (July to September) have considerably fewer PIREPs than the other seasons , so much of the map is blank. High proportions of MOG PIREPs appear less often in summer than the other seasons. Those that do appear seem to fall just east of the mountain ranges rather than over them.