Ocean wave patterns under hurricane gloria: observation with an airborne synthetic-aperture radar

Surface imagery of ocean waves under Hurricane Gloria (September 1976) has been obtained with an airborne synthetic-aperture imaging radar. Observations were obtained over most of the area within a radius of 150 kilometers around the center of the eye. These direct observations made it possible to derive the wave patterns in the region around a hurricane eye.     

Lunar apennine-hadley region: geological inplications of Earth-based radar and infrared measurements

Recently completed high-resolution radar maps of the moon contain information on the decimeter-scale structure of the surface. When this information is combined with eclipse thermal-enhancement data and with high-resolution Lunar Orbiter photography, the surface morphology is revealed in some detail. A geological history for certain features and subareas can be developed, which provides one possible framework for the interpretation of the findings from the Apollo 15 landing. Frequency of decimeter-and meter-size blocks in and around lunar craters, given by the remote-sensed data, supports a multilayer structure in the Palus Putredinis mare region, as well as a great age for the bordering Apennine Mountains scarp.     

Venus: estimates of the surface temperature and pressure from radio and radar measurements

The radio brightness temperature and radar cross section spectra of Venus are in much better accord with surface boundary conditions deduced from a combination of the Mariner V results and the radar radius than those obtained by the Venera 4 space probe. The average surface temperature and pressure are approximately 750 degrees K and 90 atmospheres.     

Impact of a catastrophic hurricane on island populations

Lizard and spider populations were censused immediately before and after Hurricane Lili on islands differentially affected by the storm surge. The results support three general propositions. First, the larger organisms, lizards, are more resistant to the immediate impact of moderate disturbance, whereas the more prolific spiders recover faster. Second, extinction risk is related to population size when disturbance is moderate but not when it is catastrophic. Third, after catastrophic disturbance, the recovery rate among different types of organisms is related to dispersal ability. The absence of the poorer dispersers, lizards, from many suitable islands is probably the result of long-lasting effects of catastrophes.     

Intense sub-kilometer-scale boundary layer rolls observed in hurricane fran

High-resolution observations obtained with the Doppler On Wheels (DOW) mobile weather radar near the point of landfall of hurricane Fran (1996) revealed the existence of intense, sub-kilometer-scale, boundary layer rolls that strongly modulated the near-surface wind speed. It is proposed that these structures are one cause of geographically varying surface damage patterns that have been observed after some landfalling hurricanes and that they cause much of the observed gustiness, bringing high-velocity air from aloft to the lowest observable levels. High-resolution DOW radar observations are contrasted with lower-resolution observations obtained with an operational weather radar, which underestimated peak low-level wind speeds.     

Simulated increase of hurricane intensities in a CO2-warmed climate

Hurricanes can inflict catastrophic property damage and loss of human life. Thus, it is important to determine how the character of these powerful storms could change in response to greenhouse gas-induced global warming. The impact of climate warming on hurricane intensities was investigated with a regional, high-resolution, hurricane prediction model. In a case study, 51 western Pacific storm cases under present-day climate conditions were compared with 51 storm cases under high-CO2 conditions. More idealized experiments were also performed. The large-scale initial conditions were derived from a global climate model. For a sea surface temperature warming of about 2.2 degrees C, the simulations yielded hurricanes that were more intense by 3 to 7 meters per second (5 to 12 percent) for wind speed and 7 to 20 millibars for central surface pressure.     

Space-based radar

The concept of national air defense against aircraft and cruise missiles has been evolving in parallel with the Strategic Defense Initiative and is being referred to as the Air Defense Initiative. One of the most promising sensor concepts for the Air Defense Initiative is space-based radar. Operated at microwave frequencies as an instrument for wide-area surveillance, space-based radar may be useful in mission areas such as fleet defense and battlefield surveillance.     

大花蕙兰高频再生体系的建立

以大花蕙兰的不同部位作外植体,对其启动诱导;采用正交试验设计等方法筛选大花蕙兰类原球茎诱导、增殖与生根壮苗的最佳培养基。结果表明:在大花蕙兰离体再生过程中,侧芽是最容易启动的外植体;MS 6-BA 1.0 mg/L NAA 0.1 mg/L AC 0.1 g/L是类原球茎诱导的最佳培养基;1/2MS 6-BA 1.0 mg/L NAA 0.1 mg/L是类原球茎增殖和幼苗分化的最适宜培养基;芽分化后,在1/2MS NAA 1.0 mg/L GA31.0 mg/L 香蕉泥150 g/L培养基中生根壮苗效果最好。     

Deconvolution of the factors contributing to the increase in global hurricane intensity

To better understand the change in global hurricane intensity since 1970, we examined the joint distribution of hurricane intensity with variables identified in the literature as contributing to the intensification of hurricanes. We used a methodology based on information theory, isolating the trend from the shorter-term natural modes of variability. The results show that the trend of increasing numbers of category 4 and 5 hurricanes for the period 1970-2004 is directly linked to the trend in sea-surface temperature; other aspects of the tropical environment, although they influence shorter-term variations in hurricane intensity, do not contribute substantially to the observed global trend.     

Modulation of hurricane activity in the gulf of mexico by the madden-julian oscillation

The Madden-Julian oscillation (MJO) is a large-scale episodic modulation of tropical winds and precipitation that travels eastward from Asia to America, with a characteristic repeat time of 30 to 60 days. Here it is shown that when MJO wind anomalies in the lower troposphere of the eastern Pacific are westerly, Gulf of Mexico and western Caribbean hurricane genesis is four times more likely than when the MJO winds are easterly. Accurate predictions of the MJO may lead to improved long-range forecasts of tropical cyclone activity.     

大花蕙兰高频再生体系优化研究

为研究大花蕙兰(Cymbidium hybridum)的高频快繁再生体系,以大花蕙兰无菌原球茎、分化苗为材料,应用正交试验进行不同激素和添加物的优化筛选。结果表明院在1/2 MS+0.3 mg/L KT+0.5 mg/L NAA+25 g/L蔗糖+7 g/L琼脂+1 g/L活性炭的培养基上大花蕙兰的原球茎增殖效果最好,新增原球茎呈深绿色、形状饱满,增殖倍数达11倍;在1/2 MS+0.1 mg/L6-BA+0.4 mg/L NAA+25 g/L蔗糖+7 g/L琼脂+1g/L活性炭的培养基上茎叶分化效果最好,分化丛生芽数量最多、颜色深绿色、生长健壮,分化倍数达6.1倍;在1/2 MS+0.2 mg/L GA3+1.0mg/L NAA+0.2 mg/L IBA+25 g/L蔗糖+7 g/L琼脂+1 g/L活性炭的培养基上生根效果最好,生根数最多,平均生根数达4条,根系生长强健。     

High-frequency switching of colony morphology in Candida albicans

The pathogenic yeast Candida albicans switches heritably and at high frequency between at least seven general phenotypes identified by colony morphology on agar. Spontaneous conversion from the original smooth to variant phenotypes (star, ring, irregular wrinkle, hat, stipple, and fuzzy) occurs at a combined frequency of 1.4 X 10(-4), but is increased 200 times by a low dose of ultraviolet light that kills less than 10 percent of the cells. After the initial conversion, cells switch spontaneously to other phenotypes at a combined frequency of 2 X 10(-2). Switching is therefore heritable, but also reversible at high frequency. The genetic basis of this newly discovered process and its possible role in Candida pathogenesis are considered.     

A radar snapshot of venus

A radar brightness map of Venus has been obtain d. It reveals interesting surface features and much structure over a large area.