Details

Autor(en) / Beteiligte

• Reid, Kimberley J.
• Arblaster, Julie M.
• Alexander, Lisa V.
• Siems, Steven T.

Titel

Spurious Trends in High Latitude Southern Hemisphere Precipitation Observations

Ist Teil von

• Geophysical research letters, 2024-03, Vol.51 (6), p.n/a

Ort / Verlag

Washington: John Wiley & Sons, Inc

Erscheinungsjahr

2024

Quelle

Wiley Online Library Journals Frontfile Complete

Beschreibungen/Notizen

• The high latitude Southern Hemisphere (SH) is an important region for Earth's climate. Ocean heat content, cryosphere interactions, Antarctic bottom water development and the cloud‐albedo feedbacks need to be understood to form a complete picture of the climate system. However, the high latitude SH is one of the most under‐observed regions due to its remoteness. The advent of satellites and reanalyses have improved our monitoring of this region. Some previous studies observed an increase in precipitation over the SH high latitudes, however we argue that some of the trends in commonly used data sets may be artifacts. We use regression analysis of trends in precipitation and the Southern Annular Mode to contrast these relationships in satellite and reanalysis products, and to evaluate precipitation over the SH. We suggest that sensor changes and the lack of in situ data available for calibration may be responsible for unusual precipitation patterns especially around 65°S. Plain Language Summary Many important processes in the Earth's climate occur at high latitudes in the Southern Hemisphere. However, due to its remoteness and inhospitable conditions, scientists have trouble obtaining data for this region. Satellites have helped to provide information about this area but are not well constrained due to a lack of in situ data. Sensor changes and the launch of new satellites means that the data can vary in quality and reliability over time. By comparing precipitation trends over the Southern Hemisphere with known climate patterns, we suggest that an observed increase in precipitation over the Southern Hemisphere high latitudes may be due to variations in the satellite technology rather than a physical increase in precipitation. This is important for understanding the impacts of climate change on Earth's water cycle and heat storage. Key Points High latitude precipitation trends are likely artifacts Sensor changes may be responsible for spurious trends in the Southern Ocean Satellite products do not agree on the zonal mean precipitation pattern in the Southern Hemisphere