Petermann, the monsoon and Antarctic soil record change at three scales
Satellite imagery recorded a major Greenland calving as two studies linked the South Asian monsoon to both hemispheres and Antarctic microbes to shared energy genes.
Science··Evening
Petermann lost a 76-square-kilometre ice slab
A Copernicus Sentinel-1 radar image from August 4 showed a 76-square-kilometre section separating from the floating tongue of Petermann Glacier in north-west Greenland. ESA describes it as the tongue's largest loss since 2012 and the Arctic's largest calving event since 2020. Regular all-weather radar coverage will allow the resulting iceberg to be tracked. The single image does not yet establish how much this event contributes to Greenland's annual ice loss.[1]
The monsoon's rain and sea track different hemispheres
Qin Wen and colleagues compared cave and marine-sediment records with 150,000 years of climate simulations. Rainfall over South Asia varies with Northern Hemisphere insolation, while Arabian Sea upwelling varies with Southern Hemisphere insolation and warming over southern Africa. The split means rainfall over the subcontinent and marine productivity that supports fisheries do not respond to the same external forcing in lockstep. The result does not forecast a particular catch; it separates two remote connections within the system.[2]
Antarctic microbes transfer energy genes horizontally
Yongyi Peng and colleagues examined 676 microbial genomes recovered from Antarctic soils and found evidence of horizontal gene transfer in about 98 per cent of species. Energy-production genes were transferred most often; genes enabling aerotrophy, or extracting energy from trace atmospheric hydrogen and carbon monoxide, repeatedly moved between distantly related lineages. The findings show that adaptation in cold, nutrient-poor soils is not confined to individual species. The sampled sites do not represent all of Antarctica, and aerotrophy alone does not explain survival.[3]
