Pavel Groisman

Evaporation changes over the contiguous United States and the former USSR: A reassessment

Observed decreases in pan evaporation over most of the United States and the former USSR during the post-WWII period, if interpreted as a decrease in actual evaporation, are at odds with increases in temperature and precipitation over many regions of these two countries. Using parallel observations of actual and pan evaporation at six Russian, one Latvian, and one U.S. experimental sites, we recalibrate trends in pan evaporation to make them more representative of actual evaporation changes. After applying this transformation, pan evaporation time series over southern Russia and most of the United States reveal an increasing trend in actual evaporation during the past forty years.

U.S. temperature and drought: Recent anomalies and trends

The spring and summer (March through August) of 2011–2012 set many new climatological records across the contiguous United States, including the hottest month in the instrumental record: July 2012. Various measures of temperature extremes and drought severity serve to put this period into historical perspective (1895 to present) and to assess to what extent the recent anomalies are consistent with observed trends. During spring and summer, anomalously high temperatures can combine with unusually dry conditions to amplify temperature and drought feedbacks. Observational data from 2011 and 2012 are strongly suggestive of such an amplification and reveal a number of significant trends for various measures of high temperatures in the United States.

Snow cover basal ice layer changes over Northern Eurasia since 1966

An analysis is made of changes in basal ice crust layer characteristics from snow cover surveys made at 958 Russian stations since 1966. The analysis revealed that substantial changes have occurred in response to two competing processes: an increase in thaws associated with strong regional warming and an increase in the duration of the basal ice layer presence on the ground, and a shortening of the snowmelt period associated with a decrease in basal ice layer event frequency and severity. The latter appears to be the more significant process over the past 40 years. Our findings support the notion that the entire spring snowmelt process has become shorter in duration and more intense when taking into account a concomitant trend toward increasing snow depths over large regions of Russia. A more intense spring melt period has important consequences for spring flood dynamics and deserves further study.

Reanalysis data underestimate significant changes in growing season weather in Kazakhstan

We present time series analyses of recently compiled climate station data which allowed us to assess contemporary trends in growing season weather across Kazakhstan as drivers of a significant decline in growing season normalized difference vegetation index (NDVI) recently observed by satellite remote sensing across much of Central Asia. We used a robust nonparametric time series analysis method, the seasonal Kendall trend test to analyze georeferenced time series of accumulated growing season precipitation (APPT) and accumulated growing degree-days (AGDD). Over the period 2000–2006 we found geographically extensive, statistically significant (p<0.05) decreasing trends in APPT and increasing trends in AGDD. The temperature trends were especially apparent during the warm season and coincided with precipitation decreases in northwest Kazakhstan, indicating that pervasive drought conditions and higher temperature excursions were the likely drivers of NDVI declines observed in Kazakhstan over the same period. We also compared the APPT and AGDD trends at individual stations with results from trend analysis of gridded monthly precipitation data from the Global Precipitation Climatology Centre (GPCC) Full Data Reanalysis v4 and gridded daily near surface air temperature from the National Centers for Climate Prediction Reanalysis v2 (NCEP R2). We found substantial deviation between the station and the reanalysis trends, suggesting that GPCC and NCEP data substantially underestimate the geographic extent of recent drought in Kazakhstan. Although gridded climate products offer many advantages in ease of use and complete coverage, our findings for Kazakhstan should serve as a caveat against uncritical use of GPCC and NCEP reanalysis data and demonstrate the importance of compiling and standardizing daily climate data from data-sparse regions like Central Asia.

Icing conditions over Northern Eurasia in changing climate

Icing conditions, particularly in combination with wind, affect greatly the operation of overhead communication and transmission lines causing serious failures, which result in tremendous economic damage. Icing formation is dangerous to agriculture, forestry, high seas fishery, for land and off coast man-made infrastructure. Quantitative icing characteristics such as weight, thickness, and duration are very important for the economy and human wellbeing when their maximum values exceed certain thresholds. Russian meteorological stations perform both visual and instrumental monitoring of icing deposits. Visual monitoring is ocular estimation of the type and intensity of icing and the date of ice appearance and disappearance. Instrumental monitoring is performed by ice accretion indicator that in addition to the type, intensity and duration of ice deposits reports also their weight and size. We used observations at 958 Russian stations for the period 1977–2013 to analyze changes in the ice formation frequency at individual meteorological stations and on the territory of quasi-homogeneous climatic regions in Russia. It was found that hoar frosts are observed in most parts of Russia, but icing only occurs in European Russia and the Far East. On the Arctic coast of Russia, this phenomenon can even be observed in summer months. Statistically significant decreasing trends in occurrence of icing and hoar frost events are found over most of Russia. An increasing trend in icing weights (IWs) was found in the Atlantic Arctic region in autumn. Statistically significant large negative trends in IWs were found in the Pacific Arctic in winter and spring.

Understanding livestock production and sustainability of grassland ecosystems in the Asian Dryland Belt

BackgroundCompanioned by economic development, a dietary shift toward higher meat consumption is seen in developing countries and transitional economies, where the demand for livestock production has been increasing in response to such a dietary shift. In the Asian Dryland Belt, approaches to meet this demand have focused on grazing intensification, cropland conversion for animal feed, and supplemental feeding. With the scarcity of water, energy, and food in the region, a key question is whether or not the current approaches are sustainable. If not, what are the pathways to increase livestock production while protecting the region’s environment for a sustainable future? We provide our reviews and discuss current approaches in response to these dietary shifts and assess their environmental resilience with a focus on the grassland ecosystems in the Asian Dryland Belt.ResultsWhile current approaches alleviate the urgent need for short-term livestock production, they lead to long-term vulnerability in food security. Trade-offs between short gains and long-term losses, between food for humans and for animals, and between agricultural intensification and environmental degradation need to be holistically examined for the sustainable development of the region. A grassland water, energy, and food nexus framework is proposed with specific recommendations to increase livestock production while considering other ecosystem services of the dryland grassland ecosystems in the Asian Dryland Belt.ConclusionsCurrent practices to increase livestock production are likely to lead to long-term, large-scale ecological degradation of the grassland ecosystems in the Asian Dryland Belt and are thus unsustainable. By considering the trade-offs in the nexus of water, land, food, and livelihoods, sustainable pathways were articulated and recommended. Future pilot studies are needed for validation and adoption.

Regional Aspects of Climate-Terrestrial-Hydrologic Interactions in Non-boreal Eastern Europe

non-boreal Eastern Europe: A Summary Statement of the Northern Eurasia Earth Science Partnership Initiative (NEESPI) Workshop held in Odessa, Ukraine, 23-28 August 2008 Topics raised during the Workshop (in 39 oral and 10 poster presentations as well as during the informal discussions) recounted various aspects of the general environmental security as well as of its components such as atmosphere, hydrosphere, coastal zone, and land cover. Different approaches (as well as their syntheses) were presented: (a) in situ and remote sensing tools to observe/monitor environmental changes in Eastern Europe; (b) modeling of environment and human impact in the region; (c) assessment of available databases; (d) accuracy assessment of modern observing techniques, sensitivity of modeling results to errors and uncertainties in initial conditions; and (e) projections of future environmental conditions in the region.

Introduction: Climate and Land-Cover Changes in the Arctic

The last 10 years have been the warmest in the Arctic during the 120-year period of instrumental observations. The global mean surface temperature during that period has increased by about 0.8°C, with stronger changes in the Arctic. Retreat of the Arctic sea ice during the past decades open an additional source of heat and water vapor in the autumn and early winter seasons. If these warming trends continue, they will significantly affect the Arctic land cover and land use, also causing impacts on the global scale. The changes will occur in the natural land cover, with perhaps the greatest effects in that part of the Arctic where the land cover has already been modified by human activities. In many Arctic areas there has been a clear shift from the land use practiced by indigenous peoples to intensive exploitation of the land for commercial and industrial uses. New navigation routes across the Arctic Ocean shelf seas are broadly discussed. If and when implemented, these routes will change the Arctic land use and the life style of the population. The International Polar Year (IPY) program involving over 200 projects with thousands of scientists from over 60 nations is coming to its final stage. This book is a compilation of the studies which have been conducted in the framework of the NASA Land-Cover/Land-Use Change Program and which have been focused on the Arctic region of Northern Eurasia, although some comparisons are made with the results in North America. The region of interest in the current book is north of 60° latitude, specifically transitional forest-tundra and tundra zones.

Northern Eurasia Future Initiative (NEFI): facing the challenges and pathways of global change in the twenty-first century

AbstractDuring the past several decades, the Earth system has changed significantly, especially across Northern Eurasia. Changes in the socio-economic conditions of the larger countries in the region have also resulted in a variety of regional environmental changes that can have global consequences. The Northern Eurasia Future Initiative (NEFI) has been designed as an essential continuation of the Northern Eurasia Earth Science Partnership Initiative (NEESPI), which was launched in 2004. NEESPI sought to elucidate all aspects of ongoing environmental change, to inform societies and, thus, to better prepare societies for future developments. A key principle of NEFI is that these developments must now be secured through science-based strategies co-designed with regional decision-makers to lead their societies to prosperity in the face of environmental and institutional challenges. NEESPI scientific research, data, and models have created a solid knowledge base to support the NEFI program. This paper presents the NEFI research vision consensus based on that knowledge. It provides the reader with samples of recent accomplishments in regional studies and formulates new NEFI science questions. To address these questions, nine research foci are identified and their selections are briefly justified. These foci include warming of the Arctic; changing frequency, pattern, and intensity of extreme and inclement environmental conditions; retreat of the cryosphere; changes in terrestrial water cycles; changes in the biosphere; pressures on land use; changes in infrastructure; societal actions in response to environmental change; and quantification of Northern Eurasia’s role in the global Earth system. Powerful feedbacks between the Earth and human systems in Northern Eurasia (e.g., mega-fires, droughts, depletion of the cryosphere essential for water supply, retreat of sea ice) result from past and current human activities (e.g., large-scale water withdrawals, land use, and governance change) and potentially restrict or provide new opportunities for future human activities. Therefore, we propose that integrated assessment models are needed as the final stage of global change assessment. The overarching goal of this NEFI modeling effort will enable evaluation of economic decisions in response to changing environmental conditions and justification of mitigation and adaptation efforts.n

Northern Eurasia in the global Earth system

Northern Eurasia is undergoing significant changes associated with warming climate and with socioeconomic changes during the entire twentieth century. Climatic changes over this vast landmass interact and affect the rate of global change through atmospheric circulation and through strong biogeophysical and biogeochemical couplings. Current and future interactions and feedbacks to the global system of this carbon- rich, cold-region component of the Earth system remain to a large extent unknown. n nThe Northern Eurasia Earth Science Partnership Initiative (NEESPI; http://neespi.org), an international and interdisciplinary program, was established to address these issues. NEESPIs overarching science question is, How do we develop our predictive capability of terrestrial ecosystems dynamics over northern Eurasia for the 21st century to support global projections as well as informed decision-making and numerous practical applications in the region? Since 2004, more than 100 international research projects have joined NEESPI, and the initiative has been endorsed by several international programs and projects.