Coupled Surface Meteorological Processes and Regional Climate

Background

World Health Organization (WHO) districts for which we have meningitis reports

Figure 1. World Health Organization (WHO) districts for which we have meningitis reports allowing us to develop a disease forecasting model relying on weather forecast information (polygons with dots); from this model, we plan on providing meningitis outbreak forecasts for the majority of districts shown (polygons).

RAL scientists are involved in a variety of projects related to hydrometeorological processes at the land–atmosphere interface including evapotranspiration, runoff (flash floods and river discharge), infiltration, snowmelt and soil moisture. With collaborators from the university and federal agency communities, RAL scientists lead and participate  in field observational studies as well as model development and model assessment activities. The major goal of these efforts is to improve our understanding and predictive capabilities of land–atmospheric interactions spanning a variety of time and space scales (weather to climate).  Field research activities broadly center on improving understanding and prediction of the factors controlling land-atmosphere exchanges with increasing emphases on complex terrain, forested and seasonally snow-covered regions.  Model activities include development of the community Noah land–surface model and coupled WRF/Noah regional climate models, development of probabilistic precipitation estimates and forecasts, and deployment of multi-model, or ‘ensemble’ prediction systems.

Current field research projects being conducted by RAL scientists include boundary layer evolution studies over the Rocky Mountain foothill regions, precipitation hydrometeor characterization studies for quantitative precipitation estimation (QPE), studies on the impacts of insect-driven forest mortality on land-atmosphere exchanges of energy, water and volatile organic compounds (VOCs), and snow energy-water balance studies. 

Model development and evaluation studies engage a broader suite of topics including flash flood prediction, research on the North American Monsoon climate system, investigating land–atmospheric feedback in semi–arid regions in the US and China, ten–year reanalysis of land–surface component for arctic region, medium range and climate forecasting applications in Bangladesh and California, enhancement of land surface models (Noah and CLM) for disturbed (fire and beetle infestation) land surfaces, and improving the Water Evaluation And Planning (WEAP) model used by water managers to assess the impact of future climate predicted precipitation on the operation of reservoirs, diversions, power production and irrigation. 

Key tools for these process and prediction studies include radars, satellites, surface observational networks, the WRF mesoscale model with the Noah land surface model for both weather and regional climate, ensemble forecast systems, a distributed version of the Noah land surface model that allows for overland, channel and subsurface flows, and the WEAP water evaluation and planning tool. The community models, including the Noah-distributed and WRF/Noah regional climate models continue to serve as frameworks from which increasingly deep interactions with the hydrological community occurs.  Each of the activities in which RAL scientists engage is aimed at advancing the science of coupled land-atmosphere exchange processes while also helping forecasting agencies, water managers and the emergency response sectors to more effectively plan for and mitigate high impact weather and climate events.

FY2009-2010 Accomplishments

  • Updated the time-varying albedo characteristics of snowpack in the Noah land surface model
  • Improved the estimation of the surface exchange coefficient in Noah
  • Expanded functionality of the Noah-distributed model for coupled, regional climate-hydrology applications
  • Conducted climate change impacts studies for the Colorado Front Range, State of California, and the country of Peru with WEAP
  • Collected and quality-controlled boundary layer/land-surface/hydrometorological data from non-infested/beetle-infested and non-burned/burned forests
  • Collected and quality controlled spatially-distributed rainfall and hydrometeor data across the Colorado Front Range in support of dual polarimetric radar QPE validation and nowcasting studies
  • Continued improvements of operational real-time calibration of NWP ensemble forecasts of weather variables over Dugway Proving Grounds
  • Quantified important errors in numerical approximations effecting multi-facted aspects of hydrological model behavior and accuracy
  • Initiated implementation of a post-processing algorithm for calibrating NWP wind speed over wind farms of the Xcel wind energy project
  • Produced operational flood forecasts for the Brahmaputra and Ganges Rivers as they enter into Bangladesh, and forecasts of the Surma and Meghna Rivers in the Northeast Highlands region of this country
  • Designed a framework for quantifying contributions of multi-physics parameterizations in hydrological models
  • Initiated new deployment of the coupled WRF/Noah-distributed model in continuously-running regional climate mode over the northern Alps region of Bavaria, Germany

FY2010-2011 Plans

  • Radar
    Figure 2. Map on left shows the location of the Col. State CHILL radar (blue star) and the ground observing network of rain gauges (blue and red squares) and other intensive ground observing sites. Panels on right show range-height indicator (RHI) plots of radar reflectivity (top), differential reflectivity (middle) and surface disdrometer measured hydrometeor drop size distributions (bottom) for a heavy rainfall event observed at the Niwot Ridge study site on Aug. 9, 2010.
    Develop an operational meningitis vaccine decision support tool utilizing ensemble weather forecast information for susceptible, developing regions of Africa (Figure 1)
  • Complete development of a set of observational-based Noah model land surface parameters for beetle-infested and burned areas
  • Develop and evaluate a new version of the Noah-Multi-Physics (Noah-MP) land surface model
  • Intercompare the performance of four land-surface models (Noah-CLM, LEAF, Noah-MP) over the Colorado Headwater region
  • Contrast impacts of land-atmosphere interactions on precipitation in IHOP-02 with those of the BAMEX-04 field campaigns
  • Continue to make improvements of flood forecasting algorithms utilizing Thorpex-Tigge forecast data and possible new regional applications
  • Develop improving post-processing algorithms and applications, including the CBRFC
  • Complete testing and evaluation of dual-polarimtric radar-based precipitation and flash flood nowcasting system for the Colorado Front Range (Figure 2)
  • Initiate new intra-seasonal forecasting project aimed at quantifying the impacts of land surface forcing on warm-season medium range precipitation forecasts in the southwest U.S. and northwest Mexico
  • Complete a climate change impacts study for Peruvian water development project
  • Expand observational and modeling activities into snowpack energy-water exchange studies in forested and un-forested environments