Establishment of Geomagnetic Observatories in Pakistan and Repeat Station Results from Northern Part of Pakistan

A geomagnetic observatory was established at Karachi （geog coord： 24.95°N, 167.14° E）, Pakistan in 1983 which comprised of AMOS-Ⅲ （Automatic Magnetic Observatory System）. In 2006 SUPARCO （Space and Upper Atmosphere Research Commission） planned to upgrade the old observatory of Karachi in order to qualify it as an IMO （Intermagnet Magnetic Observatory）. Dr. Jean Rasson agreed to give support and assist us in the upgradation. BGS （British Geological Survey） provided a complete observatory instrument setup. Due to perturbations traceable to the increased urbanization, the observatory has been shifted to a site ＂Sonmiani＂, 80 km north-west of Karachi, where long term protection from cultural noise is offered. This site in a sparsely built research complex was selected after a magnetic survey. A new observatory has also been established at Islamabad （geog cord： 33.75° N, 72.87° E） which is mountainous region. SUPARCO purchased new equipment for the establishment of new observatories. Plan of upgradation of observatory at Quetta is also under consideration in order to improve the monitoring of geomagnetic field on the western part of Pakistan. Repeat station work has been done for the northern part of Pakistan with the collaboration of IRM, Belgium. The obtained results also compared with the global geomagnetic model （IGRF）.

GPS Water Vapor and Its Comparison with Radiosonde and ERA-Interim Data in Algeria

Remote sensing of atmospheric water vapor using global positioning system（GPS） data has become an effective tool in meteorology,weather forecasting and climate research. This paper presents the estimation of precipitable water（PW）from GPS observations and meteorological data in Algeria,over three stations located at Algiers,Bechar and Tamanrasset.The objective of this study is to analyze the sensitivity of the GPS PW estimates for the three sites to the weighted mean temperature（T;）,obtained separately from two types of T;–T;regression [one general,and one developed specifically for Algeria（T;stands for surface temperature）],and calculated directly from ERA-Interim data. The results show that the differences in T;are of the order of 18 K,producing differences of 2.01 mm in the final evaluation of PW. A good agreement is found between GPS-PW and PW calculated from radiosondes,with a small mean difference with Vaisala radiosondes.A comparison between GPS and ERA-Interim shows a large difference（4 mm） in the highlands region. This difference is possibly due to the topography. These first results are encouraging,in particular for meteorological applications in this region,with good hope to extend our dataset analysis to a more complete,nationwide coverage over Algeria.

Global observation of urban expansion and land-cover dynamics usingsatellite big-data

Humans deeply influence the urbanizing of earth’s surface system in an exacerbating manner across space and time[1].Around the globe,urban land-use/cover changes reflect the intensities of human activities and land shifts from nature or semi-nature lands to man-made–dominated surfaces[2].

Narrative warm/cold variations in continental western Europe, AD 708-1426

An extended narrative dataset of the Medieval time AD 708-1426 in continental western Europe was set up. Some 30-year-moving mean seasonal temperature deviation series were reconstructed. A warming trend occurred around AD 1200. During the warm stage, seasonal cycle might be weak due to frequent cool summers. Significant warm summer conditions did not occur until the late 14th century, when the annual temperature level began decreasing. The mean warm season temperature level during the late 14th to the early 15th century might be about 0.3℃ higher than the present. It was suggested to cautiously comment on historical climates for different seasons.