A note on frame transformations with applications to geodetic datums

Rigorous equations in compact symbolic matrix notation are introduced to transform coordinates and velocities between ITRF frames and modern GPS-based geocentric geodetic datums. The theory is general but, after neglecting higher than second-order terms, it is shown that the equations revert to the formulation currently applied in most major continental datums. We discuss several examples: the North American Datum of 1983 (NAD83), the European Terrestrial Reference System of 1989 (ETRS89), the Geodetic Datum of Australia of 1994 (GDA94), and the South American Geocentric Reference System (SIRGAS). Electronic Publication     

A multiple linear statistical model for estimating the mean maximum urban heat island

Summary ¶This study examines the spatial and quantitative influence of urban factors on the surface air temperature field of the medium-sized of Szeged, Hungary, using mobile measurements under different weather conditions in the periods of March 1999–February 2000 and April–October 2002. Efforts have been concentrated on the development of the urban heat island (UHI) in its peak development during the diurnal cycle. Tasks included: (1) determination of spatial distribution of mean maximum UHI intensity and some urban surface parameters (built-up and water surface ratios, sky view factor, building height) using the standard Kriging procedure, as well as (2) development of a statistical model in the so-called heating and non-heating seasons using the above mentioned parameters and their areal extensions. In both seasons the spatial distribution of the mean maximum UHI intensity fields had a concentric shape with some local irregularities. The intensity reaches more than 2.1°C (heating season) and 3.1°C (non-heating season) in the centre of the city. For both seasons statistical model equations were determined by means of stepwise multiple linear regression analysis. As the measured and calculated mean maximum UHI intensity patterns show, there is a clear connection between the spatial distribution of the urban thermal excess and the examined land-use parameters, so these parameters play an important role in the evolution of the strong UHI intensity field. From the above mentioned parameters the sky-view factor and the building height were the most determining factors which are in line with the urban surface energy balance. Therefore in the future, using our model it will be possible to predict mean maximum UHI intensity in other cities, which have land-use features similar to Szeged.Received September 26, 2002; revised February 25, 2003; accepted March 22, 2003 Published online July 30, 2003     

Special Contribution: Pictorial Series of the Manifestations of the Dynamics of the Earth: 4. Historical Images of Rockbursts' Effects in Mines

Studia Geophysica et Geodaetica -     

Special Contributions: Pictorial Series of the Manifestations of the Dynamics of the Earth: 5. Kamchatka,Its Early Cartography and Recent Climate Changes

Studia Geophysica et Geodaetica -     

Automatic Location of Swarm Earthquakes from Local Network Data

An advanced method of automated seismic phase picking and exact location and magnitude determination of swarm micro-earthquakes from local network data is presented. The phase picker is applied in two steps: first, S-wave groups are identified using a polarisation detector, and then corresponding P-wave groups are searched for. The times of maximum P- and S-amplitudes are then used as starting points for the determination of accurate P- and S-arrival times. The maximum S-wave amplitudes are utilised for determining local magnitudes. The whole procedure is checked by simultaneous preliminary hypocentre location providing estimates of local magnitudes and a compatibility check of the candidate P- and S-phases. The closest station to the earthquake cluster is used as a master, and the phase search at the remaining stations is governed by the P- and S-phases identified at the master station. Thanks to the use of apriori information on the approximate position of hypocentres, the procedure is also capable of picking the individual P- and S-phases of sequences of overlapping swarm events. The performance of the procedure was tested by comparison of the automatically and interactively created catalogues of the January 1997 NW-Bohemia micro-earthquake swarm. With stations located at epicentral distances between 0 and 20 km, the difference between hypocentre coordinates obtained by automatic and interactive processing did not exceed 80 m for 86% events. All events above magnitude 0.5 were identified, and the automatically determined polarity of first P-wave motion proved to be correct in 89% of them.     

Köppen Climate Types in Observed and Simulated Climates

The Köppen climate classification was applied to the observed gridded climatological sets and the outputs of four general circulation models (GCMs) over the continents of the Earth. All data had been acquired via the Data Distribution Centre established by the Intergovernmental Panel on Climate Change. The ability of the GCMs to simulate the Köppen climate zones identified in the real data was explored and possible future (global warming) changes in the climate types' distribution for each GCM were assessed. Differences in the area distributions derived from the GCMs' recent climate simulations give evidence about uncertainties generally involved in climate models. As to the global warming simulations, all GCM projections of warming climate (horizon 2050) show that the zones representing tropical rain climates and dry climates become larger, and the zones identified with boreal forest and snow climates together with the polar climates are smaller.     

On the Integrability of Limited-Area Numerical Weather Prediction Model ALADIN over Extended Time Periods

This note summarizes results of the first integration of regional numerical weather prediction model ALADIN in a climate mode. The ALADIN model, developed in an international cooperation led by Météo France, is operationally used for weather prediction. The grid step of the model is 12 km; the integration domain covers a major part of Europe. A one-month-long run has been performed with this model on observed boundary conditions (represented by assimilations by the global model ARPEGE). It is demonstrated that no excessive error is generated and accumulated in the model during the integration; hence the model is integrable for extended time periods and may serve a basis for a development towards a regional climate model.