A13B-0099 1340h
Modeling the Impact of Changing Climate and Permafrost on Emission of Greenhouse Gases From the Arctic Wetlands.
There is growing evidence that climatic warming and changes in permafrost may enhance the emission of the greenhouse gases from the Arctic wetlands. Arctic soils contain approximately 455 Gt C, or 14% of the global soil carbon of which about 50Gt C are accumulated in the Arctic wetlands. Deeper seasonal thawing may lead to enhanced decomposition of the organic material and release of soil carbon to the atmosphere in the form of either CO2 (typical for dry soils with high ventilation), or CH4 (typical for wetlands where decomposition takes place under anaerobic conditions). We used the digital contours of 112,520 Siberian wetlands, permafrost and soil carbon models, and GCM-based scenarios of future climate to calculate the changes in the volume of seasonally thawing organic-rich soil and emission of greenhouse gases from the wetlands in the Russian Arctic. By 2050 the overall volume of seasonally thawing carbon-rich soils is likely to increase on average by 20% - 30%. The largest relative increase, up to 50%, will be in the northernmost permafrost locations while in the southern zone of sporadic permafrost increase in the volume of seasonally thawing organic material will be relatively small, within 10%-15%. Such changes of permafrost, higher soil temperature and longer warm period may lead to enhanced emission of greenhouse gases. It may increase by 80% at selected locations along the arctic coast, by 30%-50% over the discontinuous permafrost region, and up to 20% in the southern permafrost zone. Better drainage conditions and enhanced evapotranspiration under warmer climate may lower the water table and improve soil ventilation, ultimately shifting the currently existing balance in favor of CO2 rather than CH4 production.
A13B-0100 1340h
A New Northern Eurasia Earth Science Partnership Initiative (NEESPI): Science Plan of Integrated Approach to Regional Climate and Environment Change Studies
The Northern Eurasia Earth Science Partnership Initiative (NEESPI) is an international large-scale, integrated, regional program of research focusing on the area of Northern Eurasia initiated by NASA and Russian Academy of Sciences. A brief introduction of the NEESPI Science Plan (SP) will be presented. While extensive and diverse, Northern Eurasia has common (and unique) features, the studying of which in a corroborated fashion under the NEESPI umbrella will produce synergetic effects. SP specifically addresses the reasons to look on the region as a "single" piece: transitional economies and land use (the legacy of the former USSR), geographical features (largest landmass in the extratropics mostly isolated from humid air masses), one of the world highest sensitivities to climatic and environmental changes with feedbacks of global concern and extensive and fluent transitional zones between ecosystems. The major NEESPI science question is: How do Northern Eurasia's terrestrial ecosystems dynamics interact with and alter the biosphere, atmosphere, and hydrosphere of the Earth? These dynamics have several facets: Biogeochemical Cycles, Surface Energy and Water Cycles, and Interactions with Human Society, each of which have to be studied in their interactions and complexity. Studying of Ecosystem-Climate Interactions mechanisms and Modeling component became a centerpiece of the SP. These studies can be conducted within a suite of models that are considered as a major instrument to assess our predictive capabilities of environmental changes and ecosystem sustainability in Northern Eurasia to support numerous applications and decision making. The creation of such a suite of models and providing it with an appropriate input data stream emerges as a focus of the Initiative. Remote sensing has an important role in the NEESPI science program, providing up to date and historical, spatially explicit information to inventory and quantify changes in the land surface and in the coastal zone for use in process and modeling studies. Social aspects of the NEESPI SP include the Education and land use components.
A13B-0101 1340h
Testing MODIS Capability to Map Peatlands
Although peatlands cover only about 3 percent of our planet's land and freshwater surface, they play a major role in the global carbon cycle. Despite their importance, peatlands are largely overlooked in current large-scale vegetation mapping efforts. In this study, we investigated the potential of the MODIS sensor to capture extent and distribution of peatlands in the St. Petersburg region of Russia. We used Forest Inventory and Peat Deposit Inventory data to extract characteristics of 50 peatlands and map them across the study area. The mapped peatlands vary in size from 0.6 ha to 7710 ha and represent three major nutritional types (oligotrophic, mesotrophic, eutrophic). In addition, parts of 6 peatlands have been used for peat-mining and these were mapped separately. MODIS Nadir BRDF-Adjusted Reflectance data from 2002 at a spatial resolution of 1-km was used to empirically model continuous estimates of percent peatland and percent mined peatland. We extracted spectral information from MODIS pixels that were completely covered by our mapped areas. In total we sampled 1105 pixels, where peatlands occupied from 0 to 100 per cent; 50 per cent of these pixels were used for regression analysis and the other half for model validation. We employed a canonical correlation analysis on the MODIS reflectance bands, producing a multi-spectral percent Peatland Cover Index (PCI). The PCI was then used as the predictor in a Reduced Major Axis (RMA) regression model. Our results suggest high potential for peatland mapping with MODIS. The RMA regression models explained much of the variance in the PCI (r2 = 0.86 for mined and r2 = 0.81 for unmined peatlands). The validation showed a high correlation between observed vs. predicted peatland cover (mined: r = 0.87; unmined: r = 0.92). We will produce a peatland map for the study area from the developed PCI models and compare it with MODIS land cover products.
A13B-0102 1340h
Potential forest fire danger over Northern Eurasia: Changes during the 20$^{th}$ century
Significant climatic changes over Northern Eurasia during the 20$^{th}$ century have been reflected in numerous variables of economic, social, and ecological interests, including the natural frequency of forest fires. For the former USSR, we are now using the Global Daily Climatology Network (Gleason et al. 2002) and a new Global Synoptic Data Network archive, GSDN, created jointly by NCDC an RIHMI. Data from these archives are employed to estimate systematic changes in indices used in the United States and Russia to assess potential forest fire danger. Within the boundaries of the former USSR, each of the archives, GHCN and GSDN, includes more than 2100 stations with only approximately 1500 of them having sufficiently long meteorological time series suitable for participation in our analyses. We use three indices: (1) Keetch-Byram Drought Index, (KBDI; this index uses only daily data on maximum temperature and precipitation and is developed and widely used in the United States); (2) Modified Nesterov, and (3) Zhdanko Indices (these indices are developed and widely used in Russia; their computation requires synoptic daytime data on temperature and humidity and daily precipitation and snow on the ground). Analyses show that after calibration, time series of the days with increased potential forest fire danger constructed using each of these three indices (a) are well correlated and (b) deliver similar conclusions about systematic changes in the weather conditions conducive to forest fires. Specifically, over the entire Eastern half of Northern Eurasia (Siberia and the Russian Far East) we found a statistically significant increase in indices that characterize the weather conditions conducive to forest fires. These areas coincide with the areas of most significant warming during the past several decades south of the Arctic Circle. West of the Ural Mountains, the same indices show a steady decrease in the frequency of the "dry weather summer days" during the past sixty years. This study supports and justifies our previous findings based on a data set five-times smaller (Groisman et al. 2003) and is corroborated with available statistics of forest fires (Korovin and Zukkert 2003) and with observed changes in characteristics of the forest phenology (Lapenis et al. 2004). Scenarios of the possible future climatic change in Northern Eurasia (IPCC 2001) indicate that the changes will be most prominent in the region. The superposition of these scenarios with the present characteristics of the potential forest fire danger in the Eastern half of Northern Eurasia, show that forest fires themselves may be an important feedback mechanism affecting both the rate and magnitude of the continental climatic changes. An unfortunate corollary is a need to reassess the existing scenarios of future climatic change in Northern Eurasia. These scenarios should include accounting for interactions with the biosphere and its changes.
A13B-0103 1340h
Hemispheric-Scale Climate Response to Northern Eurasia Snow Anomalies
Seasonal snow cover represents one of the dominant land surface characteristics within Northern Eurasia. This large, contiguous region is essentially snow-free during the summer season, and completely snow-covered during the winter. However, the transition between these two states during the autumn and spring seasons is subject to considerable interannual variability. Our research over the past several years has demonstrated that anomalies in Northern Eurasia autumn snow conditions can influence winter climate throughout the entire Northern Hemisphere. Observational analyses have detected a significant statistical relationship between autumn snow anomalies and the winter Arctic Oscillation (AO) Index, the dominant mode of Northern Hemisphere climate variability. Numerical general circulation model experiments have attributed this large-scale climatic response explicitly to regional Northern Eurasia snow forcings, and identified physically-based mechanisms by which this teleconnection occurs. Additional model experiments have identified unique orographic features in Northern Eurasia which enable this relationship. Our research reveals new ways by which the surface energy budget and water cycle of Northern Eurasia interacts with and alters the Earth's atmosphere and climate. This work also suggests Northern Eurasia as a potentially important precursive region for seasonal climate prediction.
A13B-0104 1340h
Modeling study on Inter annual variation of Asian dust storms for recent 25 years with a regional dust transport model
Asian dust particles largely impact on local air quality and the regional or global climate by modifying radiative budget. It is also well known that dust storm activity in East Asia has a strong inter-annual variation. Inter annual variation of dust storm is mainly controlled by the several climatic factors (Asia monsoon/ ENSO). However the mechanism of climatic factors which drive the dust storm is not clearly understood. To clarify the climatic factors affecting the inter annual variation of dust storm, and to evaluate the radiative impact of Asian dust on the atmospheric radiation field, we simulate Asian dust transport over the springtime 25 years with the regional-scale sophisticated dust transport model. This dust model uses a desertification map including the effect of anthropogenic desertification. We will show (1) the detailed validations of the inter annual variation with the long term observations (satellite remote sensing, visibility of surface observation site), and the characteristics of inter annual variation of Asian dust; (2) the result of correlation analysis among climatic indices (ENSO index, intensity index of the Asian polar vortex, Asia monsoon index etc.) and dust activity; and (3) the evaluation of impact of dust aerosol on the atmospheric radiation field over East Asia using the aerosol optical thickness.
A13B-0105 1340h
Climate on Abnormal Occurrence of Wildfires around Eurasia and Northern America
A great many wildfires sometimes occurred around Eurasia and Northern America: especially, Siberia and Mongolia in summer of 1998 and 2002. Generally speaking, the wildfires are caused by extreme hot and dry conditions. We could see what was happened in 1998 (Kimura et al., 2002, 2003). Now we can analyze the climatic conditions in 2002. Then we found that the climatic conditions in 1998 and 2002 from Siberia to Northern America. Indeed, in 1998 summer it was high temperature and little precipitation, and it was hotter and drier than that of 2002 summer. We can see the pressure distribution at Sea Level and 500hPa in summer. The ridge or blocking high pressure at 500hPa level is seen over the western Siberia. It corresponds to the high pressure area at Sea Level in Siberia. And also the waves at the 500hPa meander effect to the climate of North America. Next, seasonal change in summer is picked up, as wildfire had seasonal change. Sometimes it rains, but sometimes no precipitation continued more than 2 weeks in Siberia. During this period, the SLP had been high level, and southern component of wind continued to blow. This phenomenon means hot and dry condition was kept. The low relative humidity air mass moved eastward gradually, but sometimes it covered for many days. While this climatic condition continues, many wildfires occurred. In addition, a olt of wildfires were occuered in Alaska in 2004 summer. We are analizing about it.
A13B-0106 1340h
Grey Scale Record in Lake Baikal Sediments: Climate Significance for the Last 20 ka.
Three sediment cores from Lake Bakal (52°N) are investigated to evidence Northern Eurasian regional climate and environmental changes. The last 20 ka are analyzed from Kasten cores (3-4 m) and short cores (60 cm) taken in turbidite free key-sites: Vydrino Shoulder, Posolsky Bank, and Continent Ridge (EU-CONTINENT project). The age-models of the cores are based on 14C AMS datings and magnetic susceptibility correlations. From the Late Glacial Maximum (LGM) to Present, sedimentation rates range around 0,05 to 0,14 mm/yr. Thus, the standard 5 mm sampling step represent a temporal resolution of no more than 100 to 30 years. The cores material was impregnated by a new polymer technique to analyze the sediments at higher resolution from continuous thin-section cover. We present continuous grey-scale record at 20 m resolution, measured in the undisturbed part of the sediment, i.e. outside punctual burrows. The grey-scale is visually controlled by optical microscopy, and compared with magnetic susceptibility. Due to sediment properties, the grey-scale provides a high resolution record of diatom/clay ratio. For the Holocene, the grey density record shows that the biogenic productivity (diatoms) is related to the highest values (120-150 units), whereas the lowest values (80-100 units) are related to clays mixed with iron oxides and phosphates. The grey densities show an opposite trend compared to magnetic susceptibility. Our Baikal results are compared with Siberian chronozones and with global ice core record from Greenland (GISP 2).
http://www.ulg.ac.be/urap/
A13B-0107 1340h
Quantifying CO2 fluxes of boreal forests in Northern Eurasia
A number of global carbon balance studies suggested that there is very likely a large carbon sink in the northern Hemisphere, but its spatial patterns and temporal dynamics remain uncertain. International research communities have recently made great efforts establishing a network of CO2 eddy flux towers across boreal forests in Northern Eurasia. The eddy flux tower network has produced and will continue to produce rich data sets of net ecosystem exchange of CO2 (NEE) at the sites. The arisen challenge is how to interpret the rapidly accumulated data sets, and how to upscale the observations into regional scale to explain the global C imbalance. In this presentation, we will introduce a new NASA-funded project that integrates the eddy tower observation, remote sensing analysis, and biogeochemical modeling for quantifying CO2 fluxes of boreal forests in Russia. We will also present some preliminary results from the satellite-based Vegetation Photosynthesis Model (VPM) model and the process-based DNDC model for boreal forests in Europe and North America.
A13B-0108 1340h
Vegetation-soil water interaction within a dynamical ecosystem model of grassland in semi-arid areas
In semi-arid areas (e.g., part of northern Eurasia), land ecosystem is primarily determined by the annual precipitation via its impact on soil moisture. Multiple equilibrium states of an ecosystem (e.g., grassland and desert) are found to coexist, and the transition from grassland to desert is often abrupt at the boundary and can occur in both spatial and temporal domains. A dynamical ecosystem model is developed to study the vegetation-soil water interaction and provide the biophysical explanation of such abrupt transitions. It considers a single vertical column of soil and one species of grass, and has three variables: living biomass, wilted biomass, and the available soil wetness. The moisture index, which is the ratio of the annual precipitation to potential evaporation, is the only external climate driving force. Both numerical results and qualitative analysis show that the land system with soil water-vegetation interaction alone can possess multiple ecosystems over arid and semi-arid regions, as observed over northern Eurasia. And these results are robust with respect to model parameters and the transformation functions. Especially, it is found that the wilted vegetation plays a very important role in shaping the transition between grassland and desert. Further details are provided in Zeng et al. (2004a,b). Reference: Zeng X. D., S. S. P. Shen, X. Zeng, and R. E. Dickinson, Multiple equilibrium states and the abrupt transitions in a dynamical system of soil water interacting with vegetation, Geophys. Res. Lett. 31, 5501, doi:10.1029/2003GL018910, 2004a Zeng X. D., X. Zeng, S. S. P. Shen, R. E. Dickinson, and Q-C Zeng, Vegetation-soil water interaction within a dynamical ecosystem model of grassland in semi-arid areas, Tellus B. (submitted), 2004b
A13B-0109 1340h
Permafrost Degradation in the Tien Shan Mountains, Central Asia
The climatic processes during the 20th century and especially during the last three decades have a significant impact on the thermal state of mountain permafrost. Geothermal observations in the Tien Shan Mountains indicate that during the last 30 years permafrost temperatures have increased by 0.2-$0.3\deg$C for undisturbed sites, and up to $0.6\deg$C of those affected by human activities. In the Northern Tien Shan, the average active layer thickness increased by 26% in comparison with the early 1970s. At the same time, most glaciers in Central Asia have a substantial loss of their masses. The glaciated area of the Zailiysky Alatau (Northern Tien Shan) has been reduced by 29.2% during 1955-90 (Vilesov and Uvarov, 2001). Mountain permafrost and associated periglacial landforms contain large quantities of stored ground ice. The moraines, rock glaciers and other coarse blocky material have especially high ice content (40-90% by volume). Coarse blocky debris of various origins is widespread in the Tien Shan and occupies a large area of high-mountain territory. Convective mass and heat transfer, especially during the cold period, are very typical for the blocky material because of its high porosity. The mean annual temperatures inside coarse debris are typically 2.5-$4.0\deg$ colder than the mean annual air temperatures. Melted and condensed water penetrates into coarse debris, then freezes and cements the debris. The result is an ice-block mass with high ice content up to 50% by volume. The approximate evaluation shows that the quantity of water stored as ground ice in the Tien Shan is comparable with the volume of modern glaciers in the region. The total volume of surface ice over the Tien Shan Mountains is about 423 km$^{3}$ (Vilesov and Belova, 1989). The estimated ground ice volume is about 320 km$^{3}$ (Gorbunov and Ermolin, 1981). Under continuing warming and recession of glaciers in Central Asia, the ground ice could increase future water supply, and the melt waters from permafrost could become an increasingly important source of fresh water in this region in the near future. Gorbunov, A. and Ermolin, E. 1981. Ground Ice of Central Asian Mountains. Glac. Studies, Moscow, 41:59-62 (in Russ.). Vilesov, E. and Uvarov, V. 2001. The evolution of modern glaciation of the Zailiysky Alatau in the 20th century. Almaty, 252 p. (in Russ.). Vilesov, E. and Belova, I. 1989. Reserves of ice and general features of modern glaciation of the Tien Shan. Geocryological Research in the Mountains of USSR, Yakutsk, 117-130 (in Russ).
A13B-0110 1340h
Assessment, Changes, and Prediction of Water Cycle Components in Central Asian Alpine Basins
To estimate the modern condition of river runoff in Tien Shan alpine basins and to forecast its variability in relation to global and regional climate changes, means of the major water cycle characteristics (air temperature, precipitation, evapotranspiration and river runoff) have been simulated using data from 212 hydro-meteorological stations and 304 precipitation gauges. The mean evapotranspiration was calculated using data on air temperature, precipitation, and the topography aspects (including type of vegetation). Findings were simulated over the Tien Shan relief using rectangular coordinates of the equivalent cone projection with standard parallels 1:500 000 scale 100 m grid resolution Digital Elevation Model covering 800 000 knotted points. Applicable GIS-based distributed River Runoff Model was implemented for regional conditions and tested in three different Tien Shan basins, taking into account snow and glacial melt, forest, grassland and irrigated areas. Simulations of glacier river runoff accounts for glacier recession by using geodetic and terrestrial photogrammetry data (1869, 1932, 1956), aerial photography (1943, 1977), GPS survey (2002), ASTER images (2003), and Shuttle Topography Radar Mission data (2000). The parameterization between measured and simulated runoff occurred by least squares method with discrepancy approximation using linear functions with multiple parameters: annual precipitation, snow and glacial runoff and first-derivative of previous year river runoff. The mean square discrepancy between measured and simulated runoff is in accordance with the root-mean-square error of measured runoff, ranging from 8% to 12%. The rank of calculated evapotranspiration revealed the same level as the river runoff. Hypothetical climate-change scenarios in Tien Shan modeled as a stepwise progression predict an increase in air temperature of $1.8\deg$C - $4.4\deg$C (i.e., on average $3\deg$) and precipitation at 0.94 to 1.54 times (1.2 times) during the XXI Century, leading to a reduction of river runoff by only 0.008 times. If we assume that precipitation remains constant and air temperature increases by $5\deg$, river runoff in Tien Shan and Central Asia can decrease two-fold due to increased evapotranspiration.
http://www.uidaho.edu/~aizen
A13B-0111 1340h
Measuring Non-spherical Airborne Dust with Space-based MISR Multi-angle Imaging.
Some of the world's largest dust plumes emanate from Northern Eurasian deserts and are expected to increasingly affect Asian ergonomics. Together with field experiments, satellite observations of dust outbreaks, placed into the context of large-scale dust transport modeling, can help understand the impact of mineral dust aerosols on past and present climate and climate predictions in North and Central Asia. Multi-angle instruments such as the Multi-angle Imaging SpectroRadiometer (MISR) provide independent constraints on aerosol properties based on sensitivity to the shape of the scattering phase function. We present an analysis of the Multi-angle Imaging SpectroRadiometer (MISR) Standard Aerosol Retrieval algorithm, updated with new non-spherical dust models (Version 16 and higher). We compare the MISR products with coincident AERONET surface sun-photometer observations taken during the passage of dust fronts. Our analysis shows that during such events MISR retrieves Angstrom exponents characteristic of large particles, having little spectral variation in extinction over the MISR wavelength range (442, 550, 672 and 866 nm channels), as expected. Also, the retrieved fraction of non-spherical particles is very high. This quantity is not retrieved by satellite instruments having only nadir-viewing cameras. We assess whether MISR aerosol optical thickness (AOT) acquired at about 10:30 AM local time, can be used to represent daily mean AOT in dust climate forcing studies, by comparing MISR-retrieved aerosol optical thickness (AOT) with AERONET daily-mean values. We also compare the effect of particle shape on MISR and MODIS dust retrievals, using co-located MISR, MODIS, and AERONET AOTs and Angstrom exponents. In most cases obtained for this study, MODIS had no retrievals due to sun-glint when MISR's narrower swath observed AERONET sties on islands surrounded by dark water. For the few coincident MISR-MODIS-AERONET dark-water, dusty condition retrievals we obtained, the MISR retrievals were in better agreement with AERONET than those from MODIS. Over bright desert sites, MODIS AOTs at visible wavelengths was systematically higher than those of AERONET and MISR. MISR-derived aerosol type mixtures for these cases included non-spherical dust components with high frequency in retrievals over dark water, and slightly lower frequency over land. The frequency with which non-spherical dust models were selected by the algorithm also decreased in dusty regions affected by pollution. Both MISR and MODIS retrievals have a high fail rate over optically thick dust plumes.
A13B-0112 1340h
Elucidating the Linkage Between Changes in Land Use, Atmospheric Mineral Dust Loading, and Precipitation in Central Asia During the Past 50-years
It is believed that both land-use/land cover changes and atmospheric mineral dust are among the main factors controlling the precipitation and hydrological cycle. Over the past 50-years Central Asia has been undergoing major human-induced land-use changes that altered the geographical area and intensity of dust sources. Desiccation of the Aral Sea and conversion of the steppe in Kazakhstan to the agriculture fields are just a few examples of occurred land-use changes. Interactions of precipitation with land use changes and atmospheric dust can occur at a variety of scales through a poorly understood series of feedback mechanisms. This study addresses this issue by performing a detailed analysis of empirical data at a variety of spatial and temporal scales. The 50-year daily precipitation observations reported from ground-based stations in Central Asia were analyzed to 1) determine the changes in the precipitation distribution and trends and 2) elucidate the potential linkages between precipitation trends and land use and dust loading changes. Utilizing several statistical techniques, we analyzed the precipitation time series for the individual stations as well as for a subset of the stations considering different time-averaging. Several criteria were used to group the stations to separate those affected by dust transport and/or by same types of land-use changes. The consistency between observed precipitation trends and those predicted by the models will be discussed.
A13B-0113 1340h
Assessment of Glacial Area and Volume Change in Tien Shan (Central Asia) During the Last 60 years Using Geodetic, Aerial Photo, ASTER and STRM Data
The water-issue problems that occur during times of persistent drought are extremely important for central Asia. Despite the presence of large deserts and prairies with very low precipitation and extremely dry climates, central Asian mountains hold one of the greatest concentrations of perennial snow and ice in the mid-latitudes and constitute a vital source of water for more then 100,000,000 people living in this region. This research aims to evaluate glacial area and ice volume changes using aerial photographs from 1943, 1977, and Satellite Remote Sensing data from 2000/2003 over the Akshiirak ice-fields and Ala Archa glacierized basin in the central and northern Tien Shan to understand changes in the glacier water resources of central Asia during the last 60 years. These data were converted from WGS-84 to STRM and then to the Pulkovo 1942 (Russian) coordinate system using a 7-parameter Helmert transformation method. For vertical validation, the STRM DEM was compared to a DEM constructed with additional 5 m and 10 m contour lines digitized from 1:25000 topographic maps for low-relief, non-glacial areas. Glacier boundaries were digitized from an ASTER L1A image acquired on August 18, 2003 and orthorectified using Orthobase digital photogrammetric package with 9.5 m RMSE of 28 ground control points. To delineate glaciers in problem areas, resulting from debris-covered termini and shadows, thermal bands and true hardware-enabled stereo viewing with nadir 3N and backward-looking 3B bands was used. Digitizing accuracy of the 2003 glacier boundaries was verified from GPS field measurements of 7 glacier termini in 2002. For surface elevation comparison, a second DEM was generated from 10 m contour lines for all glaciers (424 km$^{2}$) using 16 topographic maps of 1:25000 scale that were created using the aerial photographs of 1977. In 1943, the glaciers of the Akshiirak massif covered 424.7 km$^{2}$ and 42.8 km$^{2}$ in the Ala Archa glacierized basin. From 1943 to 1977, the glacial area shrunk to 406.8 km$^{2}$ (4.2%) in Akshiirak, and to 40.6 km$^{2}$ (5.2%) in Ala Archa Basin. From 1977 to 2003, glacial recession reached 8.6% in the Akshiirak massif and 10.5% in the Ala Archa Basin. During the last 60 years ice volume of the Akshiirak glaciers was reduced on 10 km$^{3}$. However, the overall trend of glacier recession is variable: while 150 glaciers in Akshiirak were significantly reduced, 24 glaciers increased their volume by 1.8%. According to the Russian military geodetic data and aerial photographs the Akshiirak glaciers have retreated up to 3 km from 1869 to 1943, with surface elevation decreasing 50-80 m.
http://www.uidaho.edu/~aizen
A13B-0114 1340h
Physiological Regulation of Stomatal Conductance in Boreal Forest Species: Do Species Differ and Does it Matter?
Measurements of energy and water balance over Boreal forest ecosystems have generally shown very large ratios of sensible heat flux to latent heat flux (Bowen ratio) - especially on fine summer days. This strong control on evaporation at the plant scale can restrict precipitation and effect hydrometeorlogy at the regional scale. The large Bowen ratio is, in part, explained by the low maximum stomatal conductance of Boreal forest tree species and is probably related to their very low photosynthetic capacity. However, mid-day conductance can be much lower than expected on this basis and reflects the additional effect of a dynamic feedback system between stomatal conductance and the properties of the atmospheric boundary layer. Low stomatal conductance leads to a large sensible heat flux which, in turn, leads to a deeper, warmer and dryer atmospheric boundary layer and to a greater evaporative demand on the plant, causing the stomata close still more. Predicting the response of this non-linear system presents a major challenge. Physiological studies conducted in the Canadian Boreal forest show very large differences in the tendency of species to experience mid day stomatal closure. Jack pine was found to be quite susceptible while black spruce the most resistant to mid day stomatal closure. These species had very similar photosynthetic capacity (Vmax) and Ball-Berry stomatal sensitivity coefficients. Jack pine was, however, more sensitive to inhibition of photosynthesis by elevated temperatures and, as a consequence, stomata closed as temperature and the vapor pressure deficit increased during mid day. In contrast, black spruce was much less effected. These differences could have profound implications for simulating regional scale hydrometeorology over large areas dominated by monospecific stands in the NEESPI domain.
A13B-0115 1340h
Interannual variability in summer precipitation and surface cyclone activity in northern Eurasia
This study examines the interannual variability in summer precipitation, surface cyclone activity in northern Eurasia, and their possible connections to other climate signals. An east--west seesaw alternation of relatively dry and wet extremes is the primary mode of interannual variability in summer precipitation in Siberia. This signal occurs on time scales of about 6- to 8- years, which has been pronounced during the last 30 years. Our previous works have focused on the large-scale atmospheric circulation associated with this precipitation seesaw and their generation and maintenance processes. We extend those to diagnose northern Eurasian summertime storm track activity from a Lagrangian approach. The purpose of this study is to identify occurrence locations and primary paths of surface cyclones associated with the summer precipitation seesaw events, and to confirm this seesaw signal is linked to year-to-year variation of high-latitude cyclone activity. Spatial characteristics of cyclone frequency and cyclone tracks involved in two opposite phases of the precipitation seesaw (eastern Siberia (ES)-wet--western Siberia (WS)-dry and WS-wet--ES-dry) are examined, and temporal characteristics of regional cyclone frequency are compared with the basin-scale precipitation variability. The number of cyclones increases (decreases) in the above (below) normal precipitation region in both two phases. The difference field of cyclone frequency anomalies exhibits quite similar east-west pattern in Siberia with that of precipitation. Most of cyclones moving into ES for the ES-wet--WS-dry summers originate in western Siberia and the Kara Sea, and pass through central and eastern Siberia. On the other hand, those enter WS for the WS-wet--ES-dry summers cross western Siberia. These tracks start in northeast Europe, European Russia, and the Barents Sea and extend into western and central Siberia. Summer cyclone occurrences are counted for two boxes located over the cyclone frequency dipole. Time series of cyclone counts for these boxes tend to be out-of-phase with each other. The interannual variability of the cyclone counts in box E (W) for ES (WS) significantly correlates with that of the area-averaged precipitation for the ES (WS) domain. These results suggest that the interannual variability in the cyclone activity is capable of producing the precipitation seesaw. We further explore connections of the regional precipitation and cyclone activity with various climate signals. The result shows that statistical relationships between the cyclone counts and precipitation series for the WS region and the winter (DJF) North Atlantic Oscillation (NAO) index. The correlation coefficient between the summer (JJA) counts (precipitation) in box W (the WS domain) and the winter (DJF) NAO index is -0.39 (-0.47) for 1973--2002, which exceeds the 95% confidence level. However, dynamical linkage between the summer cyclone occurrences over WS and preceding climate conditions associated with the winter NAO is still unclear.
A13B-0116 1340h
Reconstruction of Fire Spread within Wildland Fire Events in Northern Eurasia from the MODIS Active Fire Product
Russian boreal forests have been reshaped by wildland fire for millennia. While fire is a natural component of boreal ecosystems, it impacts various aspects of the environment and affects human well-being. A significant progress has been made in mapping burned area from satellite imagery, which provides consistent and fairly unbiased estimates of fire impact on areas of interest at multiple scales. Although the information provided by burned area products is highly important, the spatio-temporal dynamics of individual fire events and their impact are less known. Often fires occur over large remote areas with limited access, which makes their ground-based observation difficult. In high northern latitudes of Northern Eurasia, MODIS (Moderate Resolution Imaging Spectroradiometer) makes up to four daily observations from each of the Terra and Aqua satellites. Here we provide an approach to reconstruct the development of fire events based on active fire detections from MODIS. Fire Spread Reconstruction (FSR) provides a means for characterization of fire occurrence over large territories from remotely sensed data. Individual fire detections are clustered within a GIS environment based on a set of rules determining proximity between fire observations in space and time. FSR determines the number of fire events, their approximate size, duration, and fire spread rate. FSR clusters were compared to burned scars mapped from Landsat7/ETM+ imagery over Yakutia (Russia). While some smaller burn scars were found to be formed through a continuous burning of a single fire event, large burned areas in Siberia were created by a constellation of fire events incorporating over 100 individual fire clusters. This in part explains patterns of burning and regrowth observed within large burn scars and difficulty of end of season automated burn scar mapping. Our FSR approach allows for the analysis of fire spread as a function of land cover, fire season, fire weather and other parameters. These parameters help to identify phenomena and conditions enhancing fire propagation and therefore creating high fire danger conditions. FSR is currently applied for an AVHRR (Advanced Very High Resolution Radiometer) and MODIS fire product intercomparison and validation effort within Northern Eurasian regional GOFC/GOLD Fire network. FSR identified fire spread as one of the error sources for mapping burned areas from active fire products. It is also used to identify the points of ignition for individual fire events in spatio-temporal domain for fire danger and fire threat modeling.
A13B-0117 1340h
Land use Changes and Mineral Dust Emission in Central and East Asia: the Role of Model's Spatial Resolution
The vast arid and semi-arid regions of Northern Eurasia are the world's largest sources of atmospheric mineral dust. Over the past century human-induced changes in land use resulted in the expansion of dust sources likely causing an additional dust burden (called anthropogenic dust). Reliable assessment of the anthropogenic component of mineral dust is needed to improve the understanding of climate change in this region. Practically all previous studies (including IPCC, 2001) relied on the general circulation models (GCMs) to predict dust emission from the natural and anthropogenic sources, although it has been demonstrated that the GCM coarse resolution hampers the realistic simulation of dust entrainment processes. Here we examine how the selection of model spatial resolution affects the dust emission and implications to the assessment of anthropogenic dust in the Aral Sea and Gobi-Taklamakan regions. A series of modeling experiments has been conducted with the PSU/NCAR Mesoscale Model MM5 coupled with dust production schemes at different spatial model grids ranging from 10 km to 200 km. The effects of spatial averaging for individual dust sources with different topography, vegetation cover, surface soil properties and erodibility were investigated. By relating dust modeling to ground-based and satellite observations, we attempt to identify the appropriate temporal and spatial resolution for adequate intercomparison between model results and observational data.
A13B-0118 1340h
Projecting large-scale ecosystem change: A Forest Gap Model to Simulate Dynamics and Patterns of Eastern Eurasian Forests
Change in the cover of the vast Eurasian super-continent has a potential to interact with the atmosphere with meso- and global-scale climatic consequences. An example of one such change is the potential positive feedback attending a warming-induced greening of the northern boreal zone of Eurasia. The predictions of the surface changes involved with such an interaction involve the development of a continental-scale capability to predict such changes. This presentation will illustrate an approach to this problem with an individual-based simulation model (the forest gap model, FAREAST) that simulates the distribution, composition and dynamics of forests in Eastern Eurasia. Tests of the model are along tall mountains in Northern China and include: 1. Direct species composition comparisons between simulated and observed mature forests at the same locations; 2. Forest type comparisons between simulated and observed forests along altitudinal gradients of several different mountains; 3. Comparison with forest stands in different succession stages of simulated forests. Model comparisons with independent data indicate the FAREAST model is capable of representing many of the broad features of the forests of Northeastern China. After model validation in the Northeast China region, model applications were developed for the forests of the Russian Far East. In simulations at 31 different sites distributed across the entire Russian Far East and including a wide variety of natural forests, the model demonstrates an ability to reproduce observed vegetation pattern. Continental-scale forest cover can be simulated to a relatively realistic degree using a forest gap model with standard representations of individual-plant processes. It appears that such a model, validated relatively locally in this case, in Northeastern China, can then be applied over a much larger region
A13B-0119 1340h
Shared Knowledge for Addressing Impacts of Land Use Transitions on Reindeer Husbandry in Northern Russia
Reindeer husbandry in Northern Russia is an economic activity with a special cultural dimension of utmost importance to the indigenous peoples. Climate changes with warmer temperatures are creating significant problems now in the Arctic for the reindeer herds. These climate factors, industrial development, and the recent transition of Russia to a market economy have resulted in a nearly complete disruption of any system of supply of goods and services and health care to indigenous peoples. In turn, this has caused rapidly deteriorating health and living conditions in the indigenous reindeer herder communities. To try to address some of these issues, a NASA-reindeer herder partnership, called Reindeer Mapper, has been initiated which is establishing a system to bring indigenous traditional and local knowledge together with scientific and engineering knowledge, remote sensing and information technologies to create a more powerful information base for addressing these environmental, climate, industrial, political, and business problems. Preliminary results from the Reindeer Mapper pilot project will be presented including a special information-sharing communications system for the Reindeer Mapper project (a private intranet system), several NASA data sets useful to the herders including SAR and Landsat imagery, local knowledge of herd distributions, ground-based data, and weather observations. Results will also be presented from the first NASA-reindeer herder science and indigenous knowledge summer camp for children of reindeer herders from the Republic of Sakha (Yakutia).
A13B-0120 1340h
Seasonal Changes in SAR Backscatter of Certain Land Features in Chukotka: Preliminary Results
Studies of seasonal changes of SAR backscatter from certain land features in two locations (Anadyr river area and Vaegi settlement area) in Chukotka, Russia, have been conducted for the four seasons for the period between the years 2000 to 2004. These studies are being carried out to determine the usefulness of SAR time series data for characterization of reindeer pastures in the Russian North, to demonstrate that SAR could provide useful information about some of the key parameters which characterize pasture quality. Preliminary results provide information on seasonal changes in data from tussock and mountain tundra, and from a set of Anadyr river area lakes. The geobotanic map of Anadyr research area was used for comparison with some SAR image texture features. SAR results were compared with ground-based data as well as meteorological data from local weather stations. Also it was demonstrated how SAR data shows forest-tundra fire scars during snow and snow-free conditions. An assessment of some snow parameters based on fire scar contrast measurements was done. A similarity analysis was applied to some reindeer pasture areas to characterize the seasonal correlations in their backscatter. Based on these data some conclusions were drawn regarding the quantity of vegetation cover within the study area. Future steps for improving SAR data analysis are also discussed.
A13B-0121 1340h
Hydrologic Changes in the Large Northern Siberian Watersheds
Observational records show significant climate change in the high latitude regions over the past several decades. Hydrologic response of the large northern watersheds to climate change and variation is one of the key issues in understanding atmosphere-land interactions in the northern regions. Examination and documentation of changes in the major northern rivers are also important to studies of global change, regional water resources, and distribution of ecosystems. This presentation provides a comprehensive review of hydrologic system changes over northern Siberian regions, with emphasizes on watershed/basin-scale hydro-climatic characteristics and differences. In order to define the hydrologic regime, and to document its changes induced by human activities (particularly large reservoirs) and by climate variations/changes, we have analyzed long-term records of streamflow, river ice thickness, water temperature, and sediment records over the past 40-50 years for the largest Siberian watersheds, such as the Lena, Yenisei, Ob rivers. Our results demonstrate remarkable changes in northern hydrology system. These include changes in streamflow seasonal cycle (such as shifts of snowmelt timing and peak flow, decreases in summer discharge, and increases of winter discharge in the Siberian watersheds), thinning of river ice thickness, and warming of stream water temperatures over eastern Siberia. These changes identified indicate a hydrologic regime shift due to recent climate warming, changes in permafrost conditions, and influence of human activities over the northern regions. Our efforts continue to identify changes in the arctic hydrologic system, and to examine hydrologic responses to climatic change and human impact in the arctic regions.
http://www.uaf.edu/water
A13B-0122 1340h
Land surface model evaluation using a new soil moisture dataset from Kamennaya Steppe, Russia
The land surface affects the atmosphere through the transfer of energy and moisture and serves as the lower boundary in numerical weather prediction and climate models. To obtain good forecasts, these models must therefore accurately portray the land surface. Actual in situ measurements are vital for testing and developing these models. It is with this in mind that we have obtained a dataset of soil moisture, soil temperature and meteorological measurements from Kamennaya Steppe, Russia. The meteorological dataset spans the time period 1965-1991, while the soil moisture dataset runs from 1956-1991. The soil moisture dataset contains gravimetric volumetric total soil moisture measurements for 10 layers taken from forest, agricultural and grassland soils. The meteorological dataset contains 3-hourly measurements of precipitation, temperature, wind speed, pressure and relative humidity. We obtained longwave and shortwave radiation data from standard formulae. The data will be made available to the public via the Rutgers University Center for Environmental Prediction Global Soil Moisture Data Bank. Soil temperature is important in determining the timing, duration and intensity of runoff and snowmelt, particularly at the beginning and end of the winter when the ground is only partially frozen. Soil temperature can in turn be affected by the vertical distribution of roots. The soil temperature data are for 1969-1991. The data are daily averaged for every 20 cm to 1.2 meters in depth. These data are used to investigate the natural sensitivity of soil temperature to vegetation type and root distribution. We also use the temperature data, as well as water balance and snowfall data to test the sensitivity of the Noah land surface model (LSM) soil temperature to vertical root distribution, and what effect that has on the hydrology of the site. In addition to soil temperature data, we also have soil moisture data for several vegetation types. We compare the soil moisture time series for different vegetation types, in order to ascertain the effect of different root distributions on natural soil moisture variations, as well as provide information on the root distribution itself, which was not measured at the site. We then run several Noah LSM simulations, which include different vegetation parameters, as well as three different vertical root distributions. These distributions are the standard Noah LSM uniform root distribution, a non-uniform root distribution in which root mass density decreases exponentially with depth, using standard parameters based on the Zeng model, and a non-uniform distribution with parameters based on information about the actual root distribution at the site. The in situ soil moisture data was then used to validate the Noah LSM results. The results of those validation experiments are presented here.
A13B-0123 1340h
Long-Range Weather Forecasting In The Ukraine
The operational system for long range weather forecasting (LRF) was developed by Ukrainian Hydrometeorological Institute (UHMI) in the result of studies of general circulation and on the long-range weather forecasting which were began in 1975 by research group leaded by Prof. V. Martazinova. Three key approaches are used in the operational system LRF of UHMI: (1) Floating analog method (FAM); (2) Two-month quasi-periodicity of atmospheric processes in the troposphere of the Northern Hemisphere; (3)Ethalon-field approach. The based on the pattern recognition technique FAM is the continuation of the ideas of former Soviet Union school of long-range forecasting. The traditional method of analog was generalized and advanced as the method of "floating analog" (Martazinova and Sologub, 1986; Martazinova, 1989; 2001). FAM requires only geometrical similarity of the planetary high-level frontal zone and surface pressure on the Northern Hemisphere. The limiting conditions of the coincidence in time and space are lifted. The use of FAM made it possible to reveal the two-month quasi-periodicity of synoptic situation in the Northern Hemisphere. The strong changes of weather within month are predicted using statistical "ethalon field" approach that was developed for classification of meteorological fields in the climate research and the long-range forecasting (Martazinova and Prokhorenko, 1991). The meteorological information for the forecast is used only for the last two months before the target month. The fields of geopotential and pressure are recognized by the "ethalon-field-analog" which corresponds to two-month quasi-periodicity of the ethalon-fields. The forecast for days the strong changes of weather over the territory of Ukraine in next two months. Recognition of daily synoptic situations of last two months by the synoptic situation of two-month quasi-periodicity of atmospheric processes for ethalons when there are waves of cold and heat, strong precipitation, strong winds over the territory of Ukraine. Method of the LRF by using FAM and "ethalon field" approach is suitable for forecasting of the atmospheric circulation in the different regions of the Northern Hemisphere. For recognizing of the important meteorological events for the different regions of the Northern Hemisphere the construction of "ethalon-fields" of the strong changes of weather is necessary. The universality of proposed method was confirmed by operational forecasts for the territory of Bulgaria, Poland, the Netherlands, Germany and Great Britain. At present time LRF by this metod are official in the Ukraine. They are issued by the Department of the Climate Research and Long-Range Weather Forecasting of UHMI from 1992.