Study of Mars dynamics from lander tracking data analysis

After the touchdown of the two Viking landers on Mars, radio tracking measurements have been performed between them and Earth-based stations. With use of the first 9 months of data, we have improved the rotation rate and the mean orientation of the spin axis of Mars, referred to its mean orbit. For the first time, some nutations terms have also been estimated. Nevertheless the precise determination of the spin axis motion will require additional data collected during the extended mission. Our solution includes also the lander locations and the relativistic parameter .Paper presented at the European Workshop on Planetary Sciences, Organised by the Laboratorio di Astrofisica Spaziale di Frascati, and held between April 23–27, 1979, at the Accademia Nazionale del Lincei in Rome, Italy.     

Simulated effects of land immersion on regional arid climate: a case study of the pre-Saharan playa of Chott el-Jerid (south of Tunisia)

The potential effects on the regional climate induced by partially immersing the arid pre-Saharan playa basin of Chott el-Jerid (south of Tunisia) are investigated by comparing two multi-year (1991–2011) sets of numerical simulations each consisting of ten-member ensemble and performed using the WRF regional climate model. The first WRF ensemble is performed under current land use and land cover, while the second is carried out after introducing a virtual large and shallow surface water reservoir (a lake) in Chott el-Jerid. The most pronounced effects generated by the artificial lake are circumscribed over its surface and slightly spread downwind to the other parts of the Chott. The lake has a clear moderating effect on near-surface air temperatures by increasing (decreasing) the wintertime (summertime) air temperatures. Sensible heat fluxes are remarkably increased in winter and decreased in summer over the lake following the temperature gradient between the lake surface and the overlying atmosphere. Latent heat fluxes, moisture convergence, and water vapor mixing ratio are increased over the lake throughout the year, especially in winter. The lake also induces domain-wide decreased (increased) surface pressures and land (lake) breeze circulation in winter (summer). Simulated rainfall amounts are most increased over the lake in winter likely because of an enhanced atmospheric instability, while they slightly decrease in summer.     

Correction to: Simulated effects of land immersion on regional arid climate: a case study of the pre-Saharan playa of Chott el-Jerid (South of Tunisia)

Theoretical and Applied Climatology - In the original article, the last panel of Fig. 10 should be labeled “h”. Also some data and Table 2 caption were unfortunately incorrect.     

Utilization of the energy in ocean waves

The characteristics of ocean wind waves place certain constraints upon devices designed to convert their energy to a useful form. Here we consider the nature of these constraints and the theoretical analysis of a wave power generator that conforms to the design criteria. We also present the results of field tests with several models of the wave power generator. The experimental results support the theory and indicate that such a wave pump is suitable for power generation in a variety of circumstances.     

Projet d'observation par satellite des irregularites d'ionisation alignees sur le champ magnetique dans la magnetosphere

A study is made of conditions under which a signal of variable frequency emitted from a satellite may be guided by an ionization irregularity existing along a power line of the Earth's magnetic field, as well as conditions under which it may be reverberated to the satellite. Cases are considered of frequencies inferior and superior to the electronic gyrofrequency. From this the form of echoes is deduced, which one may expect from a satellite gravitating up to 2 Earth's radii and it is shown, by analyzing these echoes, that it may be possible to determine the characteristics of existing irregularities in the magnetoshpere along the low-latitude lines of force.

Abstract

Иэyхaoтcя ycлoвия, пpи кoтopых cигнaл c пepeмeннoй хacтoтoй, иcхoдящий oт cиyтникa, мoжeт yпpaвлятьcя нeoднopoднocтью иoнизaции, cyщecтвyющeй вдoль cилoвoй линии мaгнитнoгo пoля зeмли, a тaкжe ycлoвия, в кoтopых этoт cигнaл мoжeт быть cиoвa нaпpaвлeн cпyтникy. paccмaтpивaютcя cлyхaи хacтoт нижe и вышe ∂лeктpoннoй гиpoхacтoты. шз ∂тoгo зaклюхyoт вид ∂хo, кoтopoгo мoжнo oжидaть oт cпyтникa, пepeдвигaющeгocя вдoльopбиты нa paccтoянии дo дв paдиycoв зeмли, пpихeм yкaзывaeтcя кaк, пyтeм aнaлизa ∂тoгo ∂хo, мoжнo ycтaнoвить хapaктepиcтикy нeoднopoдиocтeй, coдepжaщихcя в мaгнитoceфpe вдoль cилoвых линий, нa низких шиpoтaх.     

Sealevel changes associated with hurricane “Gloria”

Gloria was a fast-moving, intense hurricane that grazed the North Carolina coastline in September, 1985. The resulting storm surge was measured remotely using a telephone-linked wave data system as well as a local tide gage. The surge was hindcast using the model of Jelesnianski (1967) which was developed for shore-parallel storm tracks. The agreement with measurement was quite satisfactory. The data suggest extremely rapid rise times for the peak surge of hurricanes moving at high speed along the coast.     

Burgundy regional climate change and its potential impact on grapevines

ARPEGE general circulation model simulations were dynamically downscaled by The Weather Research and Forecasting Model (WRF) for the study of climate change and its impact on grapevine growth in Burgundy region in France by the mid twenty-first century. Two time periods were selected: 1970–1979 and 2031–2040. The WRF model driven by ERA-INTERIM reanalysis data was validated against in situ surface temperature observations. The daily maximum and minimum surface temperature (T_max and T_min) were simulated by the WRF model at 8?×?8?km horizontal resolution. The averaged daily T_max for each month during 1970–1979 have good agreement with observations, the averaged daily T_min have a warm bias about 1–2?K. The daily T_max and T_min for each month (domain averaged) during 2031–2040 show a general increase. The largest increment (~3?K) was found in summer. The smallest increments (<1?K) were found in spring and fall. The spatial distribution of temperature increment shows a strong meridional gradient, high in south in summer, reversing in winter. The resulting potential warming rate in summer is equivalent to 4.7?K/century under the IPCC A2 emission scenario. The dynamically downscaled T_max and T_min were used to simulate the grape (Pinot noir grape variety) flowering and véraison dates. For 2031–2040, the projected dates are 8 and 12?days earlier than those during 1970–1979, respectively. The simulated hot days increase more than 50% in the two principal grapevine regions. They show strong impact on Pinot noir development.     

The Isaacs wave-energy pump: Field tests off the coast of Kaneohe Bay, Hawaii: November 1976 – March 1977

Field tests conducted on a wave-power pump showed that this simple design conceived by Professor John D. Isaacs is suitable for wave-energy extraction around the Hawaiian Islands. In the small model tested, over 200 W of mechanical power were produced. Larger models could extract several orders of magnitude more power. Further research needs to be done with prototype models. The transmission of the power to the shore still needs to be examined.A by-product of the operation of the pump is nutrient rich water pumped from the bottom of the pipe. In our test, the water was pumped from 300 ft. It is feasible with a similar design that the water can be pumped from 1000 ft where the water is richer in nutrients. This water could then be used to stimulate the growth of marine plants.