Abstract
This paper examines the relationship between the Antarctic Oscillation (AAO), cold waves and occurrence of frosts in the state of Santa Catarina, Brazil, during the winter quarter. Research on this topic can assist different spheres of society, such as public health and agriculture, since cold waves can influence and/or aggravate health problems and frosts can inflict economic losses especially in the agricultural sector. For the purpose of this paper, cold wave is considered as the event in which the daily average surface air temperature was at least two standard deviations below the average value of the series on the day and for two consecutive days or more. The data on the average air temperature and frost occurrences are provided by the Company of Agricultural Research and Rural Extension of Santa Catarina/Center for Environmental Information and Hydrometeorology (EPAGRI/CIRAM). The AAO was subjected to statistical analysis using significance tests for the averages (Student’s t-test) and variances (F-test) with a significance level of α = 5%. The results show that cold waves are unevenly distributed in the agroecological zones of Santa Catarina. It is found that the AAO is associated with the occurrence of frosts (in the agroecological zones represented by the municipalities of Itajaí and São José) in the state of Santa Catarina.
Highlights
The geographical situation of the southern region of Brazil in the subtropics ensures the highest thermal amplitude in the annual cycle with a greater distinction between winter and summer.The mountain ranges and the southern plateau determine contrasts in the temperature distribution, this being the only region in Brazil with snow precipitation where noticeably cold temperatures have been registered [1]
During the positive phase of the Antarctic Oscillation (AAO), low pressure anomalies occur in Antarctica and high pressure anomalies occur in the middle latitudes
During the positive phase there is a greater chance of cold events in the middle latitudes, where Santa Catarina (SC) is situated [24,27,28]
Summary
The mountain ranges and the southern plateau determine contrasts in the temperature distribution, this being the only region in Brazil with snow precipitation where noticeably cold temperatures have been registered [1]. Sharp temperature drops associated with incursions of cold air masses in the southern and southeastern regions of Brazil have great social impacts as they often cause damage, especially in the agricultural sector. These sudden temperature drops are usually accompanied by cold winds, accentuating the sensation of thermal discomfort. In different seasons of the year, these systems make temperatures drop below the expected average, since the polar air masses that come subsequently have great frequency and intensity and are responsible for the occurrences of cold and even snow [2,3]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
