7. Janeković, I., Sikirić, M. D., Tomazić, I. and Kuzmić, M. (2010): Hindcasting the Adriatic Sea surface temperature and salinity: A recent modeling experience. Geofizika, 27, 85-100.
Oceanographic model simulations of the Adriatic temperature and salinity fields for the year 2008 were compared against coastal Conductivity Temperature Depth (CTD) observations and satellite detected Sea Surface Temperature (SST) in order to evaluate the model hindcasting skills. To that end, the Regional Ocean Modeling System (ROMS) configured with horizontal resolution of 2 km and forced with 8 km resolution output from the atmospheric model ALADIN (Aire Limitée Adaptation Dynamique développement InterNational), was applied to the Adriatic Sea.
Temperature and salinity CTD measurements collected along the eastern Adriatic coast, within the framework of the Adriatic Sea Monitoring Program, exhibits correlation with model in the temperature field between 0.75 and 0.95, depending on the season/cruise, while for salinity those values are between 0.32 and 0.78. Comparison of the modeled and daily derived satellite SST for the whole 2008 year was made on each data pixel. Results show that the hindcasts are characterized with small model-to-data RMSE, namely with values in the North Adriatic 0.90 °C, in the Middle Adriatic 0.79 °C and in the South Adriatic 0.80 °C. There is a high correlation between modeled and satellite SST data with values in a range of 0.44 to 0.92, depending on month and region, with a value of 0.99 for all time records and in any of three regions.
Keywords: Adriatic Sea, Sea Surface Temperature, ROMS, in situ data
8. Anil Kumar, R., Dudhia, J. and Roy Bhowmik, S.K. (2010): Evaluation of physics options of the Weather Research and Forecasting (WRF) Model to simulate high impact heavy rainfall events over Indian Monsoon region. Geofizika, 27, 101-125.
In this paper the performance of Weather Research and Forecasting (WRF) model for simulation of heavy rainfall events in presence of monsoon depressions over the Indian monsoon region is investigated with different physics options. A number of experiments for forecasts up to 72 hours are performed with two nested domains at the resolution of 45 km and 15 km respectively. The study shows that WRF model is sensitive to the choice of convective scheme. Betts-Miller-Janjic (BMJ) cumulus scheme is found to produce better results compared to other cumulus schemes for the Indian monsoon region. The model is capable of capturing the movement of the monsoon depression with a lead time of 72 hours. The model is expected to be very useful for forecasting of rainfall and depression tracks in short range time scales over Indian monsoon region.
Keywords: Weather Research and Forecasting model, Monsoon depression, Cumulus convective scheme
9. Jurčec, V. and Dragojlović, D. (2010): The unexpected snowstorm of 13 – 14 January 2002 in Zagreb. Geofizika, 27, 127-145.
The purpose of this paper is to present the causes of an unusual event of local snowstorm which lasted continuously for 28 hours resulting in 23 cm of snow. It was poorly forecasted since it occurred under a steady surface anticyclone in south-eastern Europe, east of the Alps. In the troposphere the most noteworthy feature was the middle-upper tropospheric front in an environment marked by sinking motion presented by the Q vectors field. It formed upstream from an intensifying cold trough in less than half a day. Another extraordinary feature was a low tropopause with a breaking region exchanging tropospheric and stratospheric air just above the area of Zagreb. The processes which mainly characterised this event in synoptic scale were advections of potential vorticity in the stratosphere and troposphere along the tropospheric cold trough.
The interactions of orographically induced polar air upsloping clouds by synoptic scale in westerlies and the low level mesoscale saturated air, influenced by the terrain in the area of Zagreb by easterly flow, were considered the causes of the snowfall. Such an event leads to the “feeder-seeder” process in which large scale ascent generating higher level seeder clouds containing ice droplets large enough to efficiently washout precipitation to interact with the lower level (feeder) moisture area and cause precipitation. This is considered one of the few significant mesoscale precipitation processes that is essentially entirely microphysical in nature.
Keywords: middle-upper tropospheric front, potential vorticity, tropopause break, “feeder-seeder” washout process
10. Jelić D. and Klaić Z. B. (2010): Air quality in Rijeka, Croatia. Geofizika, 27, 147-167.
In this paper, the hourly mean ambient concentrations of nitrogen dioxide (NO2), carbon monoxide (CO), hydrogen sulfide (H2S), sulfur dioxide (SO2), ozone (O3), benzene (C6H6) and particulate matter (PM10) measured over the last 4.5 years at the two urban sites in Rijeka are analyzed. The first site is located in the center of the town, whereas the other is located in the southeastern part, closer to the industrial zone of Rijeka. The site in the center of Rijeka is subject to heavy vehicular traffic, thus exhibiting substantially higher NO2, CO and PM10 concentrations; however, the other site is characterized by much higher SO2 concentration. The diurnal and annual variations in pollutant concentrations reflect the effects of both human activity and periodic variations in meteorological conditions, whereas average weekly variations differ as per the anthropogenic emissions. Finally, in accordance with the trend of decreasing pollutant concentrations since the mid-1980s, SO2 concentrations decreased at both the sites, whereas NO2 concentration decreased at the site closer to the industrial area of Rijeka.
Keywords: ambient concentrations, urban pollution, traffic, oil refinery, temporal variations