Synthesis of river-monitoring data reveals that the average annual discharge of fresh water from the six largest Eurasian rivers to the Arctic Ocean increased by 7% from 1936 to 1999, a large-scale change in freshwater flux.
Abstract:
Synthesis of river-monitoring data reveals that the average annual discharge of fresh water from the six largest Eurasian rivers to the Arctic Ocean increased by 7% from 1936 to 1999. The average annual rate of increase was 2.0 ± 0.7 cubic kilometers per year. Consequently, average annual discharge from the six rivers is now about 128 cubic kilometers per year greater than it was when routine measurements of discharge began. Discharge was correlated with changes in both the North Atlantic Oscillation and global mean surface air temperature. The observed large-scale change in freshwater flux has potentially important implications for ocean circulation and climate.
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Q1. What contributions have the authors mentioned in the paper "Increasing river discharge to the arctic ocean" ?
The average annual discharge of fresh water from the six largest Eurasian rivers to the Arctic Ocean increased by 7 % from 1936 to 1999 this paper.
Q2. What is the effect of warming on plant growth?
Because plant growth in many mid-latitude forests is nitrogen-limited, warming has the potential to indirectly stimulate enough carbon storage in plants to at least compensate for the carbon losses from soils.
Q3. What is the role of carbon feedbacks in climate change?
The acceleration of global warming due to terrestrial carbon-cycle feedbacks may be an important component of future climate change (1).
Q4. How many times per year were the discharge measurements made?
Stage height readings to the nearest centimeter were made daily, and cross-channel measurements of discharge for rating curve calibrations were made 25 to 30 times per year in each river.
Q5. What is the recent research on carbon-cycle feedbacks?
Recent experiments with fully coupled, three-dimensional carbon-climate models suggest that carbon-cycle feedbacks could substantially accelerate (2) or slow (3) climate change over the 21st century.
Q6. Who monitors the discharge of Russian arctic rivers?
8. The Russian Federal Service for Hydrometeorologyand Environment Monitoring (Roshydromet) monitors the discharge of Russian arctic rivers.
Q7. What is the definition of the Atlantic HSP?
In addition to river runoff, the Atlantic HSP includes meltwater from sea and continental ice and precipitation minus evaporation (P – E) over the ocean.
Q8. What is the main purpose of the paper?
The downstream stations from which the data in this paper come have been monitored almost continuously from 1936 to 1999, despite a general decline in the arctic hydrologic monitoring network that began in the mid 1980s (29).
Q9. What is the effect of warming on soil carbon and nitrogen?
Here the authors show that whereas soil warming accelerates soil organic matter decay and carbon dioxide fluxes to the atmosphere, this response is small and short-lived for a mid-latitude forest, because of the limited size of the labile soil carbon pool.
Q10. What is the statistical strength of the temporal trend in combined river discharge from the arctic?
The statistical strength of the temporal trend in combined river discharge from the Eurasian arctic is greater than for individual rivers, because the estimated slope for the sum increases with the number of rivers but the standard error of this estimate increases only with the square root of the number of rivers.
Q11. What is the definition of the HSP?
temperature trends over North America that are similar to Eurasian trends over the past century support potential arctic-wide increases in river discharge (30).
Q12. What are the results of this study?
Their results challenge assumptions made in some climate models that lead to projections of large long-term releases of soil carbon in response to warming of forest ecosystems.