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Cold temperatures and a strong polar vortex allowed chemicals to gnaw away at the protective ozone layer in the north. Cold temperatures and a strong polar vortex allowed chemicals to gnaw away at the protective ozone layer in the north., Author(s): Alexandra Witze Author Affiliations: Rare ozone hole opens over Arctic -- and it's big A vast ozone hole -- probably the biggest on record in the north -- has [...]

During the Validation of the Aeroclipper System under Convective Occurrences (VASCO) test experiment in January and February 2007, eight Aeroclipper prototypes were launched from Mahe Island in the tropical Indian Ocean. The Aeroclipper is a streamlined balloon maintained in the atmospheric surface layer by a guide rope dragging on the ocean surface. While requiring some design improvements, these prototypes showed good potential for the exploration of the tropical air-sea interface, even under rough cyclonic conditions.

Documentation during January and February 2000 of the structure of severe convective storms in Mendoza, Argentina, with a cloud-physics jet aircraft penetrating the major feeder clouds from cloud base to the -45[degrees]C isotherm level is reported. Complementary radar, satellite, and radiosonde measurements are incorporated into the study. The main research goal was the description of the microphysical evolution of the convective feeders of the hailstorms from cloud base to the anvil in an attempt to gain insights into the microphysical evolution of the clouds that are associated with the high frequency of large hail in the region. The aircraft penetrated preferentially the tops of young growing elements, which were typically the major feeders to severe hailstorms, producing hail that is large (>3 cm) in size. Cloud bases typically were at 6[degrees]-14[degrees]C, with typical base updrafts of 4-7 m [s.sup.-1]. The cloud updrafts increased with height, exceeding 25 in m [s.sup.-1] at heights [greater than or equal to] 7 km and, on occasion, 40 m [s.sup.-1] at heights >8 km. Thermal buoyancies of 5[degrees]-8[degrees]C were measured in the convective towers at heights of 8-10 km. The vertical wind shear was weak below 6 km but increased strongly above that level as the west winds cleared the Andes barrier, which averages 6.1 km to the west of Mendoza. The clouds had very little coalescence and contained no detectable precipitation-sized particles >100/[micro]m at temperatures > -15[degrees]C. Nearly adiabatic cloud water with most cloud water still not converted into precipitation-sized hydrometeors (> 100/[micro]m in diameter) was found in cloud filaments within the strongest updrafts up to the level of homogeneous freezing, reaching 4 g [m.sup.-3] at -38[degrees]C in one cloud before vanishing abruptly at colder temperatures. Graupel >l mm appeared at the tops of growing new towers at temperatures < 27[degrees]C, in agreement with radar first-echo heights of about 8 km.

In 1976 and 1977, the National Oceanic and Atmospheric Administration purchased two customized WP-3D (P-3) aircraft to conduct tropical cyclone (TC) research. During their first 30 years, the P-3s have proved to be invaluable research platforms, obtaining data at the micro- to synoptic scale, with missions conducted in 134 TCs in the Atlantic and eastern Pacific Oceans and near Australia. Analyses of the observations led to many new insights about TC structure, dynamics, thermodynamics, and environmental interactions. The real-time use of the information by the National Hurricane and Environmental Modeling Centers of the National Centers for Environmental Prediction (NCEP), as well as later research, has helped to increase the accuracy of wind, flood, and storm surge forecasts and severe weather warnings and has resulted in significant improvements to operational numerical model guidance for TC-track forecasts. In commemoration of the first 30 years of research with these aircraft, this manuscript presents a brief overview of the instrumentation aboard the aircraft and the major research findings during this period.

Transformations that take into account the characteristics of balloon motion and wave propagation to infer the 'real' vertical wavelengths from the 'apparent' ones measured during soundings were derived in a flint paper. These results are now used to estimate the deviation of the saturated spectra obtained with balloon measurements from the theoretically expected shape. It is found that data stemming from slowly ascending or descending balloons may lead to a significant distortion of spectra.

Transformations that take into account the characteristics of balloon motion and wave propagation to infer the 'real' wavelengths and frequencies from the 'apparent' ones measured during sounding are derived. To estimate the differences that may arise in the observations of internal gravity waves, a statistical relation between their wavelength and period recently found from theory and experiment is applied. It is shown that it may not be possible to determine from each apparent datum a unique real value, because up to four different transformations may be applicable for each experimental datum of wavelength or frequency. However, under certain conditions this ambiguity can be removed. The omission of the appropriate transformation may lead one to seriously misinterpret the data.

The Rubsonde meteorological balloon used with the Global Positioning System (GPS), gave as precise wind measurement results compared with the Jimsphere balloon tracked with the Acquitaine radar system. The total precision of wind measurement in the case of the Rubsonde was as low as 0.3 ms (super 1-). The Rubsonde-GPS had numerous advantages, such as accuracy independent of tracking range, ability to carry a meteorological package, easy launching conditions and low-cost soundings.

The National Institute of Polar Research and the Institute of Space and Astronomical Science launched two large zero-pressure balloons from Syowa Station, the Japanese research base in Antarctica. The balloon launched on Dec 25, 1994, achieved a total circumpolar flight over Antarctica. These Polar Patrol Balloons (PPB) employ a ballast control system to automatically regulate the ceiling height. PPBs can help study electric and magnetic fields, auroral X-rays, ozone, NOx and astronomical features such as isotope separation of cosmic rays, gamma ray bursts and low energy antiparticles in cosmic rays.