Bioclimatic characteristics of the county seat cities in the Moldova - Romania region, outlined by ITU

Argument. The bioclimate is one of the most important life factors for humans, influencing a multitude of states, reactions, attitudes, actions and human activities. In the context of the regional warming of the atmosphere, in the conditions where the warming of the atmosphere of the cities of the region is faster and considering that in the cities of Suceava, Botoșani, Piatra Neamț, Iași, Bacău, Vaslui, Focșani and Galaţi there are 1,469,929 inhabitants, this study is necessary and fills a gap in scientific research with the information it brings.

Objectives. Having temperature and humidity data series from 10 stations in the 8 cities for the interval January 1, 2009 - December 31, 2022, we bring to the knowledge plan the temporal and spatial coordinates of the ITU for the Moldova region, with the attention focused on the days of the warm season in which ITU was above the thresholds of 66 (the lower limit of the alert threshold) and 80 units (the lower limit of the bio-meteorological discomfort threshold). The objectives of the study are:

• i) outlining the differences and similarities of the multiannual, annual and daily regime of the ITU, with the identification and determination of the frequency of occurrence of temporal entities in which the value increase exceeded the threshold of 66, respectively 80 units,
• ii) the identification of critical intervals from year and day in which the thermo-hygrometric complex can put man in difficulty, iii) finding some explanations related to the spatiality and temporality of the ITU, focusing on the positional, dimensional-urbanistic and synoptic factors, for the cases where the ITU has passed the threshold of 66/80 units.

Results. From all the processed time series, it emerged that the ITU can exceed the daily threshold of 66 units in the April - October interval. The highest frequency of days with ITU above 66 units is reached at all stations during summer days. ITU went up to over 80 units almost exclusively on summer days, most frequently in big cities (Iași - 9.8%, Galați - 2.9%).In the other cities, the ITU passing over 80 units is almost statistically insignificant at the daily level (in Suceava, Botoșani, Piatra Neamț and Focșani, the share of days with ITU ≥ 80 was equal to 0). Between 11-13 and 19-21 and only in the months of June-August ITU exceeded 80 units. In Iași, the share of hours with ITU over 80% was 14.6%, in Galati 9.8%, and in Piatra Neamț only 0.23%. Daily cases with ITU values above 66% held 57.5% of the time and were due to anticyclonic billow baric fields.

Conclusions. Through the ITU we demonstrated that in Moldova, on summer days, between 11:00 and 21:00, in a predominantly anticyclonic synoptic context, there is a moderate bio-meteorological risk for the population that goes outside the home during this time.