Light-absorbing Particles in Snow and Ice: Measurement and Modeling of Climatic and Hydrological impact

Light absorbing particles（LAP, e.g., black carbon, brown carbon, and dust） influence water and energy budgets of the atmosphere and snowpack in multiple ways. In addition to their effects associated with atmospheric heating by absorption of solar radiation and interactions with clouds, LAP in snow on land and ice can reduce the surface reflectance（a.k.a., surface darkening）, which is likely to accelerate the snow aging process and further reduces snow albedo and increases the speed of snowpack melt. LAP in snow and ice（LAPSI） has been identified as one of major forcings affecting climate change, e.g.in the fourth and fifth assessment reports of IPCC. However, the uncertainty level in quantifying this effect remains very high. In this review paper, we document various technical methods of measuring LAPSI and review the progress made in measuring the LAPSI in Arctic, Tibetan Plateau and other mid-latitude regions. We also report the progress in modeling the mass concentrations, albedo reduction, radiative forcing, and climatic and hydrological impact of LAPSI at global and regional scales. Finally we identify some research needs for reducing the uncertainties in the impact of LAPSI on global and regional climate and the hydrological cycle.

Assessing the Impact of Land-Use Land-Cover Change on Stream Water and Sediment Yields at a Watershed Level Using SWAT

Flint River watershed is located in northern Alabama and southern Tennessee, USA and is home to several species of rare, threatened, or endangered plants and animals in a rapidly urbanizing area. Dominant land uses are forest and agricultural, with row crops and livestock production as major farm enterprises. Soil and Water Assessment Tool (SWAT), a deterministic hydrologic model that can predict hydrologic conditions over various temporal and spatial scales, was used to simulate the hydrologic response of the watershed to land-use/land cover (LULC) change. Analysis between observed and predicted stream flow demonstrated that the initial SWAT model run requires calibration of stream parameters in order to give a more accurate output from the model. The calibration was performed with sequential uncertainty fitting, ver. 2 (SUFI-2) in the SWAT Calibration Uncertainty Program. After calibration, stream sediment yield values were compared by sub-basin between a current (2001) and three future (2030) land use scenarios, in order to identify areas in the watershed that were the most susceptible to increased sediment yield in the future. The future growth scenarios (smart, plan and sprawl) were created using the ArcGIS extension, Prescott Spatial Growth Model. Sub-basins with the greatest sensitivity for larger sediment yields were identified and prioritized for conservation efforts.

Group dynamics motivation to increase exercise intensity with a virtual partner

Background: The effect of the K?hler group dynamics paradigm(i.e., working together with a more capable partner where one's performance is indispensable to the team outcome) has been shown to increase motivation to exercise longer at a strength task in partnered exercise video games (exergames) using a software-generated partner(SGP). However, the effect on exercise intensity with an SGP has not been investigated. The purpose of this study was to examine the motivation to maintain or increase exercise intensity among healthy, physically active middle-aged adults using an SGP in an aerobic exergame.Methods: Participants(n = 85, mean age = 44.9 years) exercised with an SGP in a 6-day cycle ergometer protocol, randomly assigned to either(a)no partner control,(b) superior SGP who was not a teammate, or(c) superior SGP as a teammate(team score was dependent on the inferior member). The protocol alternated between 30-min continuous and 4-min interval lhigh-intensity session days, during which participants could change cycle power output(watts) from target intensity to alter distance and speed.Results: Mean change in watts from a targeted intensity(75% and 90% maximum heart rate) was the primary dependent variable reflecting motivational effort. Increases in performance over baseline were demonstrated without significant differences between conditions. Self-efficacy and enjoyment were significantly related to effort in the more intense interval sessions.Conclusion: Under these conditions, no K?hler effect was observed. Exercise performance during the higher-intensity interval format is more closely related to enloyment and self-efficacy beliefs compared to the continuous sessions.

On the photoevaporation,dust polarization and kinematics of two nebulae in Sh2-236

In the work presented here,the impact of magnetic field on the dynamical evolution of cometary globules Sim 129 and Sim 130 in the Sh2-236 HⅡregion and the ionized gas streaming out of their surfaces is investigated.The magnetic field morphology in the region associated with these globules is inferred using optical polarization measurements with the Sampurnanand Telescope at ARIES.The nebular emission is probed through radio continuum mapping at 1.4 GHz with the archival National Radio Astronomy Observatory(NRAO)Very Large Array(VLA)Sky Survey(NVSS)data.The correlation of these measurements suggests that photoevaporated gas from the surfaces of Sim 129 and Sim 130 accumulates in clouds and starts streaming along the magnetic field lines.The ^(12)CO(J=1-0)molecular line observations are performed towards NGC 1893 from the 14-m single dish radio telescope in Taeduk Radio Astronomy Observatory(TRAO).The velocity dispersion in the ^(12)CO(J=1-0)molecular line and the dispersion in polarization angles are considered in the Davis-Chandrasekhar-Fermi formulation to estimate the magnetic field strength towards two Sim nebulae.The average value of field strength is found to be~60μG with uncertainty of 0.5 times the estimated value.

Future Land-Use Land-Cover Scenarios for the Flint River Watershed in Northern Alabama Using the Prescott Spatial Growth Model

A changing mosaic of natural vegetation and human land uses has evolved within and around the Flint River Watershed (FRW) in Alabama and Tennessee over the past several decades. To determine the cause of change and linkage between human activities and environmental change can prove problematic. Subsequently, there is a need to produce projections of future environments based on planning instruments and socio-economic parameters. Scenarios of potential future land use land cover (LULC) change are required in order to better manage potential impacts on many environmental issues. This study creates future scenarios for the year 2030 from baseline land use of 2001, relative to three projected land use scenarios which include differences related to conservation, planning, and development. The future growth scenarios were created using the ArcGIS tool, Prescott Spatial Growth Model (PSGM). The model allows users to build different future growth scenarios based on socio-economic projections such as population, employment and other controlling factors. The simulation results indicate that LULC changes associated with future urbanization can increase by ~23% - 43% within the FRW, which will lead to significant environmental issues if not managed properly. The overall analysis and model results demonstrate the ability of future growth scenarios to explore and evaluate options for a future environment. Spatial modeling and analysis tools, such as PSGM, provide a powerful approach to evaluate potential impacts of LULC change in the future and should be used to manage urbanization in areas with more intense development.

Data Mining for Flooding Episode in the States of Alagoas and Pernambuco—Brazil

The increasing volume of data in the area of environmental sciences needs analysis and interpretation. Among the challenges generated by this “data deluge”, the development of efficient strategies for the knowledge discovery is an important issue. Here, statistical and tools from computational intelligence are applied to analyze large data sets from meteorology and climate sciences. Our approach allows a geographical mapping of the statistical property to be easily interpreted by meteorologists. Our data analysis comprises two main steps of knowledge extraction, applied successively in order to reduce the complexity from the original data set. The goal is to identify a much smaller subset of climatic variables that might still be able to describe or even predict the probability of occurrence of an extreme event. The first step applies a class comparison technique: p-value estimation. The second step consists of a decision tree (DT) configured from the data available and the p-value analysis. The DT is used as a predictive model, identifying the most statistically significant climate variables of the precipitation intensity. The methodology is employed to the study the climatic causes of an extreme precipitation events occurred in Alagoas and Pernambuco States (Brazil) at June/2010.

Using MAN and Coastal AERONET Measurements to Assess the Suitability of MODIS C6.1 Aerosol Optical Depth for Monitoring Changes from Increased Arctic Shipping

Collocated data of the moderate resolution imaging spectroradiometer (MO-DIS) Collection 6.1 aerosol optical depths (AOD) at 3 km × 3 km north of 59.9°N over ocean were assessed at 550 nm by aerosol robotic network (AERONET) data from coastal sites and marine aerosol network (MAN) data from vessels during June to October 2006 to 2018. Typically, MODIS AOD was higher at low and lower at high values than the AERONET AOD. Discrepancies were largest for sites where the Earth’s surface around the site is very heterogeneous (Canadian Archipelago, coast of Greenland). Due to the higher likelihood for sea-ice, MAN and MODIS AOD differed stronger west of Greenland and over the Beaufort Sea than at location in the Greenland and Norwegian Seas and Atlantic. MODIS AOD well captured the inter-seasonal variability found in the AERONET AOD data (R = 0.933). At all sites, MO-DIS and AERONET AOD agreement improved as time progressed in the shipping season, hinting at errors in sea-ice vs. open water classification. Overall 75.3% of the MODIS AOD data fell within the limits of the error envelops of the AERONET/MAN AOD data with MAN ranging between 87.5% and 100%. Changes in both MODIS and AERONET mean AOD between two periods of same length (2006-2011, 2013-2018) were explainable by changes in emissions for all sites.

Locating the source field lines of Jovian decametric radio emissions

Decametric(DAM) radio emissions are one of the main windows through which one can reveal and understand the Jovian magnetospheric dynamics and its interaction with the moons. DAMs are generated by energetic electrons through cyclotron-maser instability. For Io(the most active moon) related DAMs, the energetic electrons are sourced from Io volcanic activities, and quickly trapped by neighboring Jovian magnetic field. To properly interpret the physical processes behind DAMs, it is important to precisely locate the source field lines from which DAMs are emitted. Following the work by Hess et al.(2008, 2010), we develop a method to locate the source region as well as the associated field lines for any given DAM emission recorded in a radio dynamic spectrum by, e.g.,Wind/WAVES or STEREO/WAVES. The field lines are calculated by the state-of-art analytical model, called JRM09(Connerney et al., 2018).By using this method, we may also derive the emission cone angle and the energy of associated electrons. If multiple radio instruments at different perspectives observe the same DAM event, the evolution of its source region and associated field lines is able to be revealed. We apply the method to an Io-DAM event, and find that the method is valid and reliable. Some physical processes behind the DAM event are also discussed.

Forecasting tropical cyclone tornadoes and impacts:Report from IWTC-X

This report synthesizes global tropical cyclone(TC)tornado research and operational practices to date.Tornadoes are one of the secondary(and lesser researched)hazards contributing to the devastation TCs leave in their wake.While gale-force winds and storm surge produce the majority of damage and fatalities globally,TC tornadoes also pose a fatal threat,complicating evacuation plans and protective actions as the storm moves inland.Climatological studies characterize TC-spawned tornadoes as usually weak and short-lived,primarily originating from miniature supercells in the outer rainbands.These tornadic features pose challenges to forecasting and radar detection.Additionally,TC tornadoes can pose a threat to communities 12 h prior to and beyond 48 h after a TC makes landfall.Research,both basic and operational,has increased globally over the last few years in efforts to move from a climatological to ingredientsbased approach to detect and forecast TC tornadoes.While the United States has led the charge,given the increased exposure to tornadoes year round,other nations such as China,Japan,and Australia have increased their efforts to record and detect TC tornadoes.Despite these advancements,more work needs to be done globally to understand the TC environment conducive for tornadic activity.Recommendations for future forecasting and research for TC tornadoes include i)develop a comprehensive global tornado database to improve research and forecasting efforts;ii)apply innovative technology to detect tornadoes;and iii)conduct field campaigns to thoroughly sample TC tornado environments,particularly along coastlines.

Skill-assessments of statistical and Ensemble Kalman Filter data assimilative analyses using surface and deep observations in the Gulf of Mexico

基于整体 Kalman 过滤器计划，在海洋建模的一个新数据吸收算法(Quasi-EnKF ) 在这份报纸被建议。这个算法吸收表面大小(海表面高度) 不仅，而且深(2000 m ) 从进地区性的海洋模型的墨西哥湾的温度观察。与普林斯顿海洋模型(POM ) 的使用，为由吸收表面和深观察的约二年综合，这个新算法在不同决定与一个存在吸收算法(Mellor-Ezer 计划) 相比。结果证明由比较观察，新算法超过存在那个[出版摘要]

Development of an operational land water mask for MODIS Collection 6,and influence on downstream data products

Data from the Moderate Resolution Imaging Spectro-radiometer(MODIS)on-board the Earth Observing System Terra and Aqua satellites are processed using a land water mask to determine when an algorithm no longer needs to be run or when an algorithm needs to follow a different pathway.Entering the fourth reprocessing(Collection 6(C6))the MODIS team replaced the 1 km water mask with a 500 m water mask for improved representation of the continental surfaces.The new water mask represents more small water bodies for an overall increase in water surface from 1%to 2%of the continental surface.While this is still a small fraction of the overall global surface area the increase is more dramatic in certain areas such as the Arctic and Boreal regions where there are dramatic increases in water surface area in the new mask.MODIS products generated by the on-going C6 reprocessing using the new land water mask show significant impact in areas with high concentrations of change in the land water mask.Here differences between the Collection 5(C5)and C6 water masks and the impact of these differences on the MOD04 aerosol product and the MOD11 land surface temperature product are shown.