River ice responses to a warming Arctic—recent evidence from Russian rivers

This paper looks at the response of river ice to recent warming in the Arctic at six major downstream gauges on large Russian rivers flowing to the Arctic Ocean. For the Severnaya Dvina, Ob, Yenisey, Lena, Yana and Kolyma we determine how river ice has changed in recent years and we try to understand the underlying causes of those changes. Long-term variability and trends in beginning and ending dates of ice events, duration of ice conditions, and maximum ice thickness were analyzed over 1955–2012. Significant changes in timing of ice events and a decrease in ice thickness were found for the five Siberian rivers. Duration of ice conditions decreased from 7 days for the Severnaya Dvina, Lena and Yenisey to almost 20 days for the Ob at Salekhard. The change in timing of ice events is consistent with changes in regional air temperature, which has significantly increased at each of these river gauges, except Lena-Kusur. The primary cause of the considerable increase in maximum ice thickness was not identified. Variation of mean winter air temperature and river discharge do not correlate well with maximum ice thickness and it is assumed the influence of specific local conditions can play a more important role in ice formation at these locations. Understanding this interrelationship across the Eurasian pan-Arctic using more comprehensive data archives for river ice and discharge is therefore needed

River Discharge, Arctic Report Card: Update for 2011

Total annual discharge, 1813 km3 /year, in 2010 from the six largest Eurasian rivers (Sev. Dvina, Pechora, Ob, Yenisey, Lena and Kolyma) flowing into the Arctic Ocean was very close to the 1936-2009 long-term mean of 1808 km3 /year. Mean annual discharge, 514 km3 /year, in 2010 from the four large North American Arctic rivers (Mackenzie, Yukon, Back and Peel) was ~3% lower than the long-term mean (529 km3 /year)

River Discharge, in Chapter 5, Arctic, State of the Climate in 2010

Several large-scale climate patterns influenced climate conditions and weather patterns across the globe during 2010. The transition from a warm El Niño phase at the beginning of the year to a cool La Niña phase by July contributed to many notable events, ranging from record wetness across much of Australia to historically low Eastern Pacific basin and near-record high North Atlantic basin hurricane activity. The remaining five main hurricane basins experienced below- to well-below-normal tropical cyclone activity. The negative phase of the Arctic Oscillation was a major driver of Northern Hemisphere temperature patterns during 2009/10 winter and again in late 2010. It contributed to record snowfall and unusually low temperatures over much of northern Eurasia and parts of the United States, while bringing above-normal temperatures to the high northern latitudes. The February Arctic Oscillation Index value was the most negative since records began in 1950

Record Russian river discharge in 2007 and the limits of analysis

The Arctic water cycle has experienced an unprecedented degree of change which may have planetary-scale impacts. The year 2007 in particular not only was unique in terms of minimum sea ice extent in the Arctic Ocean but also was a record breaking year for Eurasian river inflow to the Arctic Ocean. Over the observational period from 1936 to 2006, the mean annual river discharge for the six largest Russian rivers was 1796 km3 y−1, with the previous record high being 2080 km3 y−1, in 2002. The year 2007 showed a massive flux of fresh water from these six drainage basins of 2254 km3 y−1. We investigated the hydroclimatological conditions for such extreme river discharge and found that while that year\u27s flow was unusually high, the overall spatial patterns were consistent with the hydroclimatic trends since 1980, indicating that 2007 was not an aberration but a part of the general trend. We wanted to extend our hydroclimatological analysis of river discharge anomalies to seasonal and monthly time steps; however, there were limits to such analyses due to the direct human impact on the river systems. Using reconstructions of the naturalized hydrographs over the Yenisey basin we defined the limits to analysis due to the effect of reservoirs on river discharge. For annual time steps the trends are less impacted by dam construction, whereas for seasonal and monthly time steps these data are confounded by the two sources of change, and the climate change signals were overwhelmed by the human-induced river impoundments. We offer two solutions to this problem; first, we recommend wider use of algorithms to \u27naturalize\u27 the river discharge data and, second, we suggest the identification of a network of existing and stable river monitoring sites to be used for climate change analysis

Discharge Characteristics and Changes over the Ob River Watershed in Siberia

This study analyzes long-term (1936–90) monthly streamflow records for the major subbasins within the Ob River watershed in order to examine discharge changes induced by human activities (particularly reservoirs and agricultural activities) and natural variations. Changes in streamflow pattern were found to be different between the upper and lower parts of the Ob watershed. Over the upper Ob basin, streamflow decreases in summer months and increases in the winter season. The decreases in summer are mainly due to water uses along the river valley for agricultural and industrial purposes and to reservoir regulation to reduce the summer peak floods. The increases in winter streamflow are caused by reservoir impacts to release water for power generation over winter months. In the lower Ob regions, however, streamflow increased during midsummer and winter months and weakly decreased in autumn. These increases in summer flow are associated with increases in summer precipitation and winter snow cover over the northern Ob basin. Because of reservoir regulations and water uses in the upper parts of the Ob basin, it is a great challenge to determine hydrologic response to climate change and variation at the basin scale. Discharge records observed at the Ob basin outlet do not always represent natural changes and variations mainly due to impacts of large dams; they tend to underestimate the natural runoff trends in summer and overestimate the trends in winter and autumn seasons. This study clearly demonstrates regional differences in hydrologic response to climate changes and variations within a large watershed such as the Ob River. It also illustrates that, relative to climatic effects, human activities are sometimes more important and direct in altering regional hydrologic regimes and affecting their long-term changes particularly at both seasonal and regional scales. It is, therefore, necessary to consider human activities in regional/global environment change analyses and further examine their impacts in other large northern watersheds

Environmental science applications with Rapid Integrated Mapping and analysis System (RIMS)

The Rapid Integrated Mapping and analysis System (RIMS) has been developed at the University of New Hampshire as an online instrument for multidisciplinary data visualization, analysis and manipulation with a focus on hydrological applications. Recently it was enriched with data and tools to allow more sophisticated analysis of interdisciplinary data. Three different examples of specific scientific applications with RIMS are demonstrated and discussed. Analysis of historical changes in major components of the Eurasian pan-Arctic water budget is based on historical discharge data, gridded observational meteorological fields, and remote sensing data for sea ice area. Express analysis of the extremely hot and dry summer of 2010 across European Russia is performed using a combination of near-real time and historical data to evaluate the intensity and spatial distribution of this event and its socioeconomic impacts. Integrative analysis of hydrological, water management, and population data for Central Asia over the last 30 years provides an assessment of regional water security due to changes in climate, water use and demography. The presented case studies demonstrate the capabilities of RIMS as a powerful instrument for hydrological and coupled human-natural systems research

Development of Distributed Research Center for analysis of regional climatic and environmental changes

We present an approach and first results of a collaborative project being carried out by a joint team of researchers from the Institute of Monitoring of Climatic and Ecological Systems, Russia and Earth Systems Research Center UNH, USA. Its main objective is development of a hardware and software platform prototype of a Distributed Research Center (DRC) for monitoring and projecting of regional climatic and environmental changes in the Northern extratropical areas. The DRC should provide the specialists working in climate related sciences and decision-makers with accurate and detailed climatic characteristics for the selected area and reliable and affordable tools for their in-depth statistical analysis and studies of the effects of climate change. Within the framework of the project, new approaches to cloud processing and analysis of large geospatial datasets (big geospatial data) inherent to climate change studies are developed and deployed on technical platforms of both institutions. We discuss here the state of the art in this domain, describe web based information-computational systems developed by the partners, justify the methods chosen to reach the project goal, and briefly list the results obtained so far

Pan‐Arctic river discharge: Prioritizing monitoring of future climate change hot spots

The Arctic freshwater cycle is changing rapidly, which will require adequate monitoring of river flows to detect, observe, and understand changes and provide adaptation information. There has, however, been little detail about where the greatest flow changes are projected, and where monitoring therefore may need to be strengthened. In this study, we used a set of recent climate model runs and an advanced macro‐scale hydrological model to analyze how flows across the continental pan‐Arctic are projected to change and where the climate models agree on significant changes. We also developed a method to identify where monitoring stations should be placed to observe these significant changes, and compared this set of suggested locations with the existing network of monitoring stations. Overall, our results reinforce earlier indications of large increases in flow over much of the Arctic, but we also identify some areas where projections agree on significant changes but disagree on the sign of change. For monitoring, central and eastern Siberia, Alaska, and central Canada are hot spots for the highest changes. To take advantage of existing networks, a number of stations across central Canada and western and central Siberia could form a prioritized set. Further development of model representation of high‐latitude hydrology would improve confidence in the areas we identify here. Nevertheless, ongoing observation programs may consider these suggested locations in efforts to improve monitoring of the rapidly changing Arctic freshwater cycle

Widespread decline in hydrological monitoring threatens Pan‐Arctic Research

Operational river discharge monitoring is declining in both North America and Eurasia. This problem is especially severe in the Far East of Siberia and the province of Ontario, where 73% and 67% of river gauges were closed between 1986 and 1999, respectively. These reductions will greatly affect our ability to study variations in and alterations to the pan‐Arctic hydrological cycle

Variability in river temperature, discharge, and energy flux from the Russian pan‐Arctic landmass

We introduce a new Arctic river temperature data set covering 20 gauges in 17 unique Arctic Ocean drainage basins in the Russian pan‐Arctic (ART‐Russia). Warm season 10‐day time step data (decades) were collected from Russian archival sources covering a period from 1929 to 2003 with most data falling in the range from the mid‐1930s to the early 1990s. The water temperature data were combined with river discharge data to estimate energy flux for all basins and over the Russian pan‐Arctic as a whole. Tests for trend were carried out for water temperature, river discharge, and energy flux. Spatially coherent significant increases in the maximum decadal river temperature were found in the European part of the Russian pan‐Arctic. Several other drainage basins showed significant changes, but there was no strong pattern either in the connections between variables or spatially. The trend in area averaged energy flux for the three largest drainage basins (Ob, Yenisey, Lena) combined was found to be significantly decreasing. We speculate that in the Yenisey basin, this decrease was due to large impoundments of river water. The lack of consistency between temperature and energy flux trends was due to the difference in timing between peaks in river temperature and river discharge. The mean area averaged energy flux from the Russian basins was 0.2 W m−2. Using this mean we estimated the total energy flux from the entire Russian pan‐Arctic, both gauged and ungauged, to be 82 EJ a−1