Josefine AxelssonPhD student
About me
- PhD student at the Department of Physical Geography - Climate Science and Quaternary Geology Research Unit, Paleoclimate Modelling Group. Supervisor: Qiong Zhang. Co-supervisors: Jesper Sjolte, Andreas Nilsson och Margareta E Hansson
- Member of the Bolin Centre for Climate Research: Research Area 1 (Ocean-atmosphere dynamics and climate), 3 (Hydrosphere, Cryosphere and Climate) and 5 (Historical to millennial climate variability)
- Member of the PhD council and the physical geography department board.
My research aims to use stable water isotopes (SWI) from precipitation and other paleo records along with models embedded with SWI diagnostics, to investigate the processes in the hydrological cycle in the monsoon regions (primarily Asia). The focus of the research will be to compare observational SWI with model results and examine the value of using SWI to understand monsoon variability in the past and present.
Teaching
I am currently involved in the following courses:
Climate Model Simulations, 7.5 credits
Climate and Society, 15 credits
Methods in Physical Geography and Quaternary Geology, 15 Credits
Research
- Past-present-future monsoon variability revealed by stable water isotopes, 2018-2020, VR
- Simulating green Sahara with an earth system model, 2018-2021, VR
Stable water isotopes and modelling
Stable water isotopes (SWI) enables an in-depth evaluation of the physical representation of the hydrological cycle within the model.
For paleoclimate studies, forward modelling of climate proxies such as water would reveal further insights into temperature and spatial isotope-temperature relationships and the effects of climate change imprinted in paleo records.
Climate reconstructions using SWI
Observational studies have linked paleoclimatic isotope data to non-local patterns of climate variability, particularly to midlatitude atmospheric circulation patterns and to variations in the tropics. Hence, paleoclimate reconstructions may better utilize isotope data as proxies by combining them with isotope‐enabled climate models.
Current work
I am currently working on projects focusing on data-model comparisons between isotope enabled models and paleoclimatic archives (focus on speleothems). The main focus is on the last millennium and is done both on a global scale as well as on the Indian Summer monsoon region. The projects involves both statistical assessments (globally) and an aim to produce climate field reconstructions (Indian Summer monsoon) using data assimilation techniques and speleothem proxy records.
Publications
A selection from Stockholm University publication database
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Simulating the mid-Holocene, last interglacial and mid-Pliocene climate with EC-Earth3-LR
2021. Qiong Zhang (et al.). Geoscientific Model Development 14 (2), 1147-1169
ArticleRead more about Simulating the mid-Holocene, last interglacial and mid-Pliocene climate with EC-Earth3-LRAs global warming is proceeding due to rising greenhouse gas concentrations, the Earth system moves towards climate states that challenge adaptation. Past Earth system states are offering possible modelling systems for the global warming of the coming decades. These include the climate of the mid-Pliocene (similar to 3 Ma), the last interglacial (similar to 129-116 ka) and the mid-Holocene (similar to 6 ka). The simulations for these past warm periods are the key experiments in the Paleoclimate Model Intercomparison Project (PMIP) phase 4, contributing to phase 6 of the Coupled Model Intercomparison Project (CMIP6). Paleoclimate modelling has long been regarded as a robust out-of-sample test bed of the climate models used to project future climate changes. Here, we document the model setup for PMIP4 experiments with EC-Earth3-LR and present the large-scale features from the simulations for the mid-Holocene, the last interglacial and the mid-Pliocene. Using the pre-industrial climate as a reference state, we show global temperature changes, large-scale Hadley circulation and Walker circulation, polar warming, global monsoons and the climate variability modes - El Nino-Southern Oscillation (ENSO), the Pacific Decadal Oscillation (PDO) and the Atlantic Multidecadal Oscillation (AMO). EC-Earth3-LR simulates reasonable climate responses during past warm periods, as shown in the other PMIP4-CMIP6 model ensemble. The systematic comparison of these climate changes in past three warm periods in an individual model demonstrates the model's ability to capture the climate response under different climate forcings, providing potential implications for confidence in future projections with the EC-Earth model.
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The Role of El Niño in Driving Drought Conditions over the Last 2000 Years in Thailand
2020. Katherine Power (et al.). Quaternary 3 (2)
ArticleRead more about The Role of El Niño in Driving Drought Conditions over the Last 2000 Years in ThailandIrregular climate events frequently occur in Southeast Asia due to the numerous climate patterns combining. Thailand sits at the confluence of these interactions, and consequently experiences major hydrological events, such as droughts. Proxy data, speleothem records, lake sediment sequences and tree ring chronologies were used to reconstruct paleo drought conditions. These trends were compared with modelled and historic El Nino Southern Oscillation (ENSO) data to assess if the ENSO climate phenomena is causing droughts in Thailand. Drought periods were found to occur both during El Nino events and ENSO neutral conditions. This indicates droughts are not a product of one climate pattern, but likely the result of numerous patterns interacting. There is uncertainty regarding how climate patterns will evolve under climate change, but changes in amplitude and variability could potentially lead to more frequent and wider reaching hydrological disasters. It is vital that policies are implemented to cope with the resulting social and economic repercussions, including diversification of crops and reorganisation of water consumption behaviour in Thailand.
Show all publications by Josefine Axelsson at Stockholm University