Southern hemisphere reference middle atmosphere

The wind part of the rocket-based empirical model of the middle atmosphere of the Southern Hemisphere is revised on the basis of new rocket and radar data. Wind and temperature values from this empirical model are compared with corresponding values from the satellite-based reference atmosphere compiled by Barnett and Corney. General similarity of the two models is confirmed, though marked discrepancies are sometimes revealed.     

The temporal variation of mean gravity of atmosphere

One of the precise widely used global Zenith Hydrostatic Delay (ZHD) model is based on the gravity value at the centroid of the atmospheric column at the station of observation and gravity value at the centroid is constant in this model for a specific location throughout the year. However, as the content and extent of atmosphere varies temporally, its centroid and consequently gravity value at the centroid also varies. Apart from this, the actual atmospheric condition of different region is not alike. Therefore, there is a need to develop a regional mean gravity model and development of such model has been discussed in this paper. To obtain the mean gravity model, first a regional model of centroid height of atmospheric column was developed as a function of the surface pressure and temperature. It was developed by multiple regressions between estimated centroid of the atmosphere and surface pressure, surface temperature using radiosonde data of five radiosonde stations spread over the Indian subcontinent. Three years radiosonde data from 2006 to 2008 was used for each station. The root mean square error in estimating centroid of the atmospheric column is about ±326 m, which is negligible considering the variability of the atmosphere and its content. The centroid height model has been used to formulate the mean gravity model, considering uniform lapse rate in gravity with height. It is found that proposed mean gravity model provides temporal variation of mean gravity values at the centroid and thus matches with the reality. The interesting advantage of the developed model is that the model shows diurnal variation of mean gravity. The accuracy of ZHD has shown of the order of about 0.3 mm using the developed regional mean gravity model. However, already developed ZHD model has shown a slight inferior result compared to the developed model. These models have shown accuracy of about 0.8 mm and 0.6 mm.     

Reports to COSPAR from the International Lunar Exploration Working Group (ILEWG)

In accordance with its charter, the International Lunar Exploration Working Group (ILEWG) reports to COSPAR, and a summary was given at the Beijing COSPAR 2006 Assembly on ILEWG activities conducted since the previous COSPAR 2004 assembly held in Paris. This included reports from the 6th and 7th ILEWG International Conference on Exploration and Utilization of the Moon, held respectively in Udaipur, India on 22–26 November 2004 (ICEUM6) and in Toronto, Canada on 18–23 September 2005 (ICEUM7). We give in this issue of Advances in Space Research the “lunar declarations” from these ICEUM conferences, as well as for the ICEUM8 conference held in Beijing immediately after the 2006 COSPAR Assembly. One year after the COSPAR Beijing assembly, the 9th ILEWG International Conference on Exploration and Utilization of the Moon (ICEUM9), was held in Sorrento, Italy on 18–23 September 2007. We report also in this issue the “Sorrento Lunar Declaration” in advance of the ILEWG formal report to be given at the COSPAR Assembly to be held in Montreal, Canada in July 2008.     

Proposed ozone reference models for the middle atmosphere

Since the publication of the last COSPAR International Reference Atmosphere (CIRA 72), large amounts of ozone data acquired from satellites have become available in addition to increasing quantities of rocketsonde, balloonsonde, Dobson, M83, and Umkehr measurements. From the available archived satellite data, models are developed for the new CIRA using 5 satellite experiments (Nimbus 7 SBUV and LIMS, AEM-2 SAGE, and SME IR and UVS) of the monthly latitudinal and altitudinal variations in the ozone mixing ratio in the middle atmosphere. Standard deviations and interannual variations are also quantified. The satellite models are shown to agree well with a previous reference model based on rocket and balloon measurements.     

COSPAR Symposium 2017 News

<正>The 3rd COSPAR Symposium on Small Satellites for Space Research will be held in Jeju,Korea from 18 to 22 September 2017.The symposium program is designed to cover the wide scope of space research under the theme ofSmall Satellites for Space Research.The keynote,plenary and interdisciplinary talks will give the insight of space research with small satellite platform and     

A middle atmosphere temperature reference model from satellite measurements

Temperature fields in the stratosphere and mesosphere have been derived from radiance measurements made by the Nimbus 5 SCR, the Nimbus 6 PMR, and the Nimbus 7 SAMS and LIMS radiometers. These instruments cover different latitude and height ranges and different times during the 1973–1983 period. The problems of combining different data sets are discussed, and examples from a proposed model atmosphere for the stratosphere and mesosphere are presented. The model is given in terms of zonal means and amplitude and phase of zonal waves 1 and 2 for temperature and geopotential height, as functions of latitude and pressure for each calendar month. Comparisons are made with the CIRA 1972 and the Koshelkov Southern Hemisphere models and with the SAMS results and in-situ rocket/radio sondes.     

A proposed international tropical reference atmosphere up to 80 km

Motivated by the need in many aerospace applications for a meaningful reference atmosphere characteristic of the whole of the tropics in both the northern and southern hemispheres of the globe, a proposal is made here for such an atmosphere upto an altitude of 80 km. The proposal is based on balloonsonde, rocketsonde and grenade and falling sphere data, respectively, in the range of about 0–20, 20–50 and 50–80 km height. The final proposal consists of six linear segments in the temperature distribution, with temperature values in degrees Centigrade of 27, ?9, ?74, ?5, ?5, ?74 and ?74 at altitudes of 0, 9, 16, 46, 52, 75 and 80 km respectively. The sea level pressure is taken as 1010 mb, and abridged tables of quantities of interest in meteorological and aerospace applications are provided.     

Proposed reference models for nitrous oxide and methane in the middle atmosphere

Data from the Stratospheric and Mesospheric Sounder (SAMS) on the Nimbus 7 satellite, for the three years from January 1979–December 1981, are used to prepare a reference model for the long-lived trace gases methane (CH₄) and nitrous oxide (N₂O) in the stratosphere. The model is presented in tabular form on seventeen pressure surfaces from 20 to 0.1 mb, in 10° latitude bins from 50S to 70N, and for each month of the year. The means by which the data quality and interannual variability, and some of the more interesting globally and seasonally variable features of the data are discussed briefly.     

Report of the COSPAR mars special regions colloquium

In this paper we present the findings of a COSPAR Mars Special Regions Colloquium held in Rome in 2007. We review and discuss the definition of Mars Special Regions, the physical parameters used to define Mars Special Regions, and physical features on Mars that can be interpreted as Mars Special Regions. We conclude that any region experiencing temperatures > −25 °C for a few hours a year and a water activity > 0.5 can potentially allow the replication of terrestrial microorganisms. Physical features on Mars that can be interpreted as meeting these conditions constitute a Mars Special Region. Based on current knowledge of the martian environment and the conservative nature of planetary protection, the following features constitute Mars Special regions: Gullies and bright streaks associated with them, pasted-on terrain, deep subsurface, dark streaks only on a case-by-case basis, others to be determined. The parameter definition and the associated list of physical features should be re-evaluated on a regular basis.     

Proposal for a reference model of the middle atmosphere of the southern hemisphere

Available rocketsonde information has been used to compile tables of monthly mean temperature, pressure, density and zonal wind for the middle atmosphere of the southern hemisphere with the purpose of revising similar tables presented to COSPAR earlier. The altitude range is 25 to 80 km in steps of 5 km. The latitude range is 0° to 70°S with a 10° step. The compatability of different sets of temperature measurements is discussed. Mean values of temperature, pressure and zonal wind obtained for the southern hemisphere are compared with northern hemisphere model values. Large differences between the hemispheres (up to 20°C in temperature, 20–30% in pressure, 30–50 m/s in wind) imply that reference atmospheres such as CIRA should be complemented by southern hemisphere climatology.     

Highlights of the 1975 URSI/COSPAR workshop on the IRI

Some of the presentations made at the IRI Workshop held at Louvain in 1985 have not appeared in the Proceedings. Some discussions which took place during the workshop could be of interest in future work. This article tries to highlight the IRI modelling aspects in the four principal height regions of the ionosphere.