ENGIN5201 Surface Water Hydrology Assignment 1: Climate Systems Impact

This document presents a solution to an ENGIN5201 Surface Water Hydrology assignment. The solution begins by defining system science and explaining why hydrology at the catchment scale can be considered an open system, referencing the hydrological cycle's energy and moisture transfer aspects. It then delves into the influence of climate systems on Victoria's weather, describing the Indian Ocean Dipole (IOD) and its effect on rainfall patterns, the impact of frontal systems characterized by temperature shifts, and the role of the subtropical ridge in influencing seasonal weather variations. The assignment solution is supported by references to relevant literature, providing a comprehensive overview of the topics covered and their practical implications.

Solution (a):
The system science can be defined as an interdisciplinary field in which various topics are
studied such as, system complexity in nature, social and other scientific field. Some of the
system science methods involve agent-based modelling, system dynamics modelling, micro-
simulation and the big data methods ("Systems Science").
The hydrological cycle system operates as an outcome for the surplus of incoming radiation
and the back radiation. On that basis, if the cycle of system involves in the energy changes at
the catchment scale then the hydrological cycle is an open system and if the hydrological
cycle operates in terms of moisture movement then it is a closed system. This closed system
involves in the transfer and the transformation of the water which is the major concern of the
hydrologist (DOOGE, n.d.).
Solution (b):
Indian Ocean dipole and its impact on weather of Victoria:
Indian Ocean dipole can be elaborated as the difference between in sea surface temperature
between the eastern and the western Indian Ocean. In other terms, it can be defined by the
difference in sea surface temperature between two dipoles or poles or areas, in which one
pole is the Arabian sea, which can be termed as western Indian ocean and another one is the
eastern pole, which can be termed as eastern Indian Ocean south of Indonesia.
The IOD affects the weather of Australia region and other nearby countries which surround
the Indian Ocean basin. It is a main contributor of rainfall variability in this area. When the
position of the dipole is in a positive phase then SSTs around Indonesia are cooler than the
average value while SSTs in the western Indian Ocean are warmer than the normal value.
There is an increment in the easterly winds across the Indian Ocean in connection with the
SST pattern. The convection reduces in the nearby region of Australia. It causes an outcome
as suppressed rainfall over the Australian area, with 3-4 rainfall for the SWLD ("Climate
drivers of the South West Land Division", 2019).
Frontal System and its impact on weather of Victoria:

Frontal system is an air system which from due to the opposition of the warm and cold air
masses. The boundary from where the air mass transition occurs from cold to warm is known
as cold front and if this transition occurs from warm to cold then it is known as warm front.
The passage of this frontal system can bring sudden extreme changes in weather, at more
continental areas of the world. From the literature observation, it is observed that in Denver,
Colardo, the temperature reached at a balmy 270C, and after 24 hours, it reflected the
clearance of a cold front temperature at -70C with heavy snow fall. (Nelis, 2019)
Subtropical Ridge and its impact on weather of Victoria:
The subtropical ridge can be elaborated as a belt of high pressure systems which circles the
southern hemisphere mid-latitudes. This region can be defined as the globe between 230S and
660S. it is a dominant impact on the weather of Australia. It brings generally dry climate in
the southern Australia in summer. In the winter season, it migrates to the northern region by
which it allows the cold fronts and the low pressure system at the southern ocean. Due to this,
a heavy rainfall occurs in the Southern Australia.

References
Climate drivers of the South West Land Division. (2019). Retrieved 26 March 2020, from
https://www.agric.wa.gov.au/climate-weather/climate-drivers-south-west-land-
division>
DOOGE, J. THE HYDROLOGIC CYCLE AS A CLOSED SYSTEM. Retrieved 26 March
2020, from https://www.tandfonline.com/doi/pdf/10.1080/02626666809493568
Systems Science. (n.d.). Retrieved March 26, 2020, from
https://www.mailman.columbia.edu/research/population-health-methods/systems-
science
Nelis, A. (2019, October 16). Weatherwatch: how frontal systems work. Retrieved March 26,
2020, from https://www.theguardian.com/news/2019/oct/16/weatherwatch-how-
frontal-systems-work