Written by Alice Wilson and Victoria Ticha
Tahereh Alinejadtabrizi is a climate scientist working on one of the most complex research projects in the Southern Hemisphere.
The Southern Ocean, which encircles Antarctica, is an essential yet underexplored region for understanding the Earth’s climate. Its impact extends globally by regulating weather patterns and ocean currents. Thanks to its unique features, like vast expanses of sea ice and strong winds, the Southern Ocean drives heat and carbon exchange between the atmosphere and the deep ocean, which helps to regulate our global climate, even slowing the effects of climate change.
However, current climate models struggle to accurately represent the Southern Ocean’s climate dynamics due to biases related to aerosols and clouds. These biases result in inaccurate data on sunlight reaching the ocean’s surface. To address this problem, a new research project called the Clouds And Precipitation Experiment at Kennaook (or CAPE-k) was launched in April 2024. Its mission is to gather comprehensive data on clouds and precipitation over the Southern Ocean.
Tahereh Alinejadtabrizi is a climate scientist who is working on this research problem. She is a current PhD student at Monash University and the Australian Research Council (ARC) Centre of Excellence for Climate Extremes, where her work focuses on understanding how aerosols, clouds, and precipitation interact and how these processes impact our climate.
She explained: “The Cape K project is a significant breakthrough, allowing access to comprehensive meteorological data for this region. This and existing aerosol observations will enhance our understanding of these interactions and advance climate science in the Southern Hemisphere.”
From engineer to climate scientist
In 2015, while working on her master’s thesis in environmental engineering, Ms Alinejadtabrizi was exposed to climate modelling for the first time, which sparked her interest in problem-solving as a climate scientist.
“My project assessed the climate change impacts in South Iran to inform the design of a port in this region,” explained Ms Alinejadtabrizi.
“That was the first time I used outputs from climate models, and it was really a big milestone… I found the climate models really interesting.”
Ms Alinejadtabrizi was particularly fascinated by the uncertainties in the climate models. These uncertainties impact how confident we can be in what the models are telling us. Climate models can provide extremely useful information; however, they also contain uncertainties and assumptions we should be aware of to apply their information appropriately. One reason for these uncertainties is that scientists still need to fully understand some climate system processes.
“I was looking at how climate change will affect wind and, subsequently, the waves and sedimentation where the port was being built. It was my first time faced with biases and uncertainties in climate models, and I decided I wanted to work to better understand these processes to help fix the uncertainties in the climate models.”
And so, in 2021, Ms Alinejadtabrizi started her PhD at Monash University with the ARC Centre of Excellence for Climate Extremes. Her research focuses on low-level clouds over the Southern Ocean, one of climate models’ biggest sources of uncertainty.
Tackling climate uncertainty by studying clouds
Many people don’t know that the Southern Ocean is the cloudiest place on Earth, and much is unknown about the cloud processes in this region. This impacts how climate models simulate our future climate, as clouds have an important role in regulating the climate.
Depending on cloud properties, they can either reflect sunlight into space, cooling the Earth or allowing more light to reach the Earth’s surface, causing warming. This balance is crucial for understanding how greenhouse gases are impacting global temperatures.
Ms Alinejadtabrizi’s latest research examined how aerosols interact with shallow clouds over the Southern Ocean. Aerosols are tiny particles in the sky that are known to affect clouds. These aerosol-cloud interactions are one important contributor to the uncertainties in this region.
Ms Alinejadtabrizi said she had to find a way around the lack of cloud observations or measurements due to this region’s tough conditions, which made field studies very difficult. She utilised available precipitation information, aerosol records, and satellite data, employing machine learning to understand the low-level cloud morphology in the area.
“Employing all of the different kinds of available datasets together to try and understand cloud processes is really interesting to me. It allows me to use my creativity and bring innovation,” she said.
The findings from this study are useful for understanding the aerosol budget over the Southern Ocean, allowing the simulation of low-level clouds with much better accuracy.
Ms Alinejadtabrizi explained: “We found the cloud properties are really sensitive to the amount of aerosols over the Southern Ocean. We also saw that rain plays a role in washing the aerosols out of the sky. As the rain falls, it takes aerosols with them, removing them from the atmosphere.
“It’s like a small piece of the big puzzle: the climate models. Each puzzle piece helps us to better understand our current and future climate, which is really important for mitigation and adaptation strategies.”
Recently, Ms Alinejadtabrizi moved on to her next project, looking more in-depth at the aerosols and what weather processes impact them. After that, she plans to start tracking the clouds from when they form to when they disappear.
The CAPE-k research project
Ms Alinejadtabrizi recently travelled to Cape Grim for the opening of the Cloud and Precipitation Experiment at Kennaook (CAPE-k). Located at the northwestern tip of Tasmania, Cape Grim is where her PhD data is collected.
The CAPE-k project aims to gather cloud and precipitation data to address the challenges of simulating these processes over the Southern Ocean. Based at the Cape Grim Baseline Air Pollution Station (CGBAPS) in remote Tasmania, this research initiative seeks to enhance scientists’ understanding of these dynamics and improve climate model accuracy.
“The CAPE-k project is a dream for climate scientists working on climate model biases in the Southern Hemisphere. These observations give us the opportunity to better analyse all the data together and get a better understanding of what’s really going on there.”
Once her PhD is completed at the end of the year, Ms Alinejadtabrizi intends to start a postdoc to continue working in this area. By this time, she may be able to use the data collected from the CAPE-k project.
For people wanting to get into climate science, Ms Alinejadtabrizi’s advice is to “believe in yourself” and then do whatever makes you feel you are doing the thing that aligns most with your values.
“Trust it and just keep working on that one thing. It will give you the opportunity to pursue what you really want,” she said.
