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Abstract Globally, lake surface water temperatures have warmed rapidly relative to air temperatures, but changes in deepwater temperatures and vertical thermal structure are still largely unknown. We have compiled the most comprehensive data set to date of long-term (1970–2009) summertime vertical temperature profiles in lakes across the world to examine trends and drivers of whole-lake vertical thermal structure. We found significant increases in surface water temperatures across lakes at an average rate of + 0.37 °C decade−1, comparable to changes reported previously for other lakes, and similarly consistent trends of increasing water column stability (+ 0.08 kg m−3decade−1). In contrast, however, deepwater temperature trends showed little change on average (+ 0.06 °C decade−1), but had high variability across lakes, with trends in individual lakes ranging from − 0.68 °C decade−1to + 0.65 °C decade−1. The variability in deepwater temperature trends was not explained by trends in either surface water temperatures or thermal stability within lakes, and only 8.4% was explained by lake thermal region or local lake characteristics in a random forest analysis. These findings suggest that external drivers beyond our tested lake characteristics are important in explaining long-term trends in thermal structure, such as local to regional climate patterns or additional external anthropogenic influences.
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This content will become publicly available on August 6, 2026
Are historical trends in weather consistent with model predictions in the Central United States?
Abstract Model projections predict increasing temperatures and precipitation change in many locations in the Central United States. To provide perspective on what these trends might bring relative to what has already happened, we compared historical temperature and precipitation change with what models from the Coupled Model Intercomparison Project (CMIP6) predict. The analysis focuses on regions represented by five long‐term agroecosystem research sites along a latitudinal transect from Michigan to Iowa, Missouri, Oklahoma, and Mississippi. We analyzed trends in long‐term records (≥50 years) of precipitation and temperature data at annual and monthly scales using indicators that characterize extreme and average temperature and rainfall amounts. Results show that temperatures have changed from 1900 to 2020, more for minimum (0.1°C–0.3°C decade−1) than maximum (−0.1°C–0.2°C decade−1), more for winter (−0.1°C–0.3°C decade−1) than summer (−0.1°C–0.1°C decade−1), and more often in the north than in the south. Except in Mississippi, annual precipitation has increased at rates of 25 mm decade−1or greater over 1950–2020, but monthly trends were inconsistent. Projected trends suggest continued temperature increases, highlighting the urgent need for research on management systems that are resilient to such increases.
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- Award ID(s):
- 2224712
- PAR ID:
- 10630428
- Publisher / Repository:
- Soil Science Society of America
- Date Published:
- Journal Name:
- Journal of Environmental Quality
- ISSN:
- 0047-2425
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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