7. LSA-NW DATA REQUIREMENTS AND ENHANCEMENTS

The participants at the LSA-NW Detailed Design workshop were provided a summary description entitled "Potential Data Availability for GCIP Research in the LSA-NW". Some recommendations were provided by the work sessions on the data requirements for the research activities they recommended. They also provided recommendations for enhancements to the data potentially available.

The data requirements for the LSA-NW can be summarized at least qualitatively. The Regional Model Output archive from the three regional mesoscale models will be continued with some enhancements. The Satellite Data Products from the operational satellites will be continued. More emphasis will be placed on the use of satellite data products by including data products from the Earth Observing System and the Landsat 7 which are expected to become available during the second year of the Enhanced Annual Observing Period. The In-Situ data collected is similar in type to that collected for the other LSAs in the Mississippi River basin.

The data requirements assembled at the Detailed Design Workshop in October 1998 and supplemented by further analysis of the research activities were assembled into a comprehensive list. This listing provides the basis for the Draft Document entitled "Tactical Data Collection and Management Plan for the LSA-NW Enhanced Annual Observing Period".

7.1 Focus Study Areas

The Work Sessions at the GCIP Detailed Design Workshop held in October, 1998 were asked to recommend:
(i) A candidate list of sub-basins that could serve as focus study areas for process studies and model    development and evaluation activities.

(ii) A candidate list of Intermediate and Small Scale Areas that could provide the data needed for model validation and evaluation activities for hydrometeorological prediction and water resources.

(iii) Enhancements which the GCIP Project should make to assure adequate data are available for the recommended GCIP research activities.

The 12 sites that were suggested were analyzed for the suitability of existing infrastructure and their potential contributions to the GCIP research activities planned for the LSA-NW. As a result of this more detailed investigation, it was decided to identify only the Black Hills Region in this Major Activities Plan. Several other sites are being considered in the Missouri River basin and it is likely that one or more of these sites will become GCIP focus study locations.

The Black Hills of South Dakota and Wyoming cover a region of approximately 200 km in north-south extent by 100 km east-west. The Black Hills rise about 1.2 km above the surrounding plains. This region has been the focus of scientific studies by USGS, NASA, and NSF. The observation network in this region include 60 precipitation gages, 60 observational wells, and 70 streamflow gages. NASA is supporting an intensive field observation period in spring 1999, which will provide enhanced observations of atmospheric water vapor and condensate fluxes for water balance studies. This intensive observation period will include a research aircraft, a wind profiler, and a ground-based microwave radiometer (along with the WSR-88D and rawinsonde sites at Rapid City, SD). This ISA offers the opportunity to study the orographic effects of an isolated mountain range on the precipitation processes and its spatial distribution. Also, it is an excellent test-bed for evaluating the effect of coupled model resolution on precipitation forecasts.

7.2 Model Output During the EOP

The plans for model output data are remaining fairly constant during the five year EOP with an emphasis on the regional model output. These model output data are available for the LSA-NW from the beginning of the EOP in October 1995 for the Eta model. The GEM and MAPS model output data were archived from a later date. There are no plans to subset the model output data by geographical coverage. The regional model output is divided into three types:
(1) One-dimensional vertical profile and surface time series at selected locations referred to as Model Location Time Series (MOLTS)

(2) Gridded two-dimensional fields, especially ground surface state fields, ground surface flux fields, top-of-the-atmosphere (TOA) flux fields, and atmospheric fields referred to as Model Output Reduced Data Sets (MORDS)

(3) Gridded three-dimensional atmospheric fields containing all of the atmospheric variables produced by the models.

Further details on the regional model output is given in Appendix B and in the Tactical Data Collection and Management Plan for the LSA-NW Enhanced Annual Observing Period.

7.3 GCIP Enhancements for the LSA-NW

The sparsity of in-situ measurements in the LSA-NW is well known and it was recognized during the implementation planning for GCIP in 1992 and 1993 that some actions will be needed to alleviate this problem. Also, the implementation schedule for the Weather Services Modernization put this region at the end of the schedule for installing equipment such as the WSR-88D sites. For these reasons the study of the LSA-NW was scheduled for the end of the GCIP Enhanced Observing Period.

At this time GCIP can make use of three approaches to enhance the data available for the LSA-NW:

GCIP can take advantage of the improvements to the current operational satellite remotely sensed data and resulting data product. The current schedules for the launch of the first Earth Observing System (TERRA, formerly EOS-AM1) and the Landsat 7 satellites makes it unlikely that GCIP can expect much data from these satellites before the second year of the EOP.

GCIP has placed a heavy emphasis on the archiving of the data from three regional Mesoscale Models during the EOP starting in 1995. These data have provided geographic coverage over the LSA-NW since the beginning and will provide a valuable set of enhanced data for GCIP research. GCIP will continue to archive the data from these same three regional mesoscale models for the remainder of the EOP. A one-year evaluation period for this model output is tentatively scheduled during the second year of the LSA-NW EOP. In addition some of the vertical profiles, identified as Model Location Time Series (MOLTS) are being relocated to the LSA-NW to further enhance the regional model output data available over this region.

The lack of surface flux data in the LSA-NW is particularly noteworthy. GCIP supported the installation of such sites in the LSA-SW and the LSA-NC. Among the recommendations at the LSA-NW Detailed Design workshop was one to install at least two flux sites in the LSA-NW. Specifically, it was recommended that one of the flux sites be collocated with the current Surface Radiation (SURFRAD) site now operating at Ft. Peck, MT.This recommendation is being implemented.

The lack of soil moisture measurements is also particularly noteworthy. It was recommended at the LSA-NW Detailed Design Workshop that GCIP take steps to assemble a data set of soil moisture estimates. In particular, GCIP needs to extend the soil moisture data and analyses now ongoing in the Oklahoma region to the LSA-NW. GCIP plans to respond to the requirements for soil moisture information through a combination of approaches:

i) The Data collection and Management (DACOM) will inventory and compile the data from all the available soil moisture measurement sites in the LSA-NW. These sites will be identified in the Tactical Data Collection and Management Plan for the LSA-NW Enhanced Annual Observing Period.

ii) GCIP is currently supporting work in NCEP to develop and implement a Land Data Assimilation System (LDAS) as an off-line operation to provide inputs such as soil moisture to the Eta Model. When the LDAS is implemented as an operation in NCEP, DACOM will include these soil moisture data as part of the model output data archived from the Eta regional mesoscale model.

iii) GCIP will take steps to facilitate the analysis of soil moisture over the annual cycle across a range of latitudes by implementing enhancements to a North-South Transect along 96 degrees West longitude within a range of plus or minus three degrees longitude. A Soil Water and Temperature Transect along this longitude (SOWATT-96W) was started in 1996 which runs from Prairie View, TX (30N latitude) to Bemidji, MN (~47N latitude). The soil moisture measurement sites in this Transect are shown in Figure 7-1. The data collection from this Transect is currently on hold awaiting the calibration of the soil moisture data obtained from locations in the Oklahoma "Moistnet" network (ARM/CART site, Little Washita Micronet and Oklahoma Mesonet). It is planned to enhance the SOWATT-96W Transect by placing MOLTS locations for regional model output at key locations along the Transect as shown in Figure 7-2.

Another recommendation from the Workshop is that GCIP assemble a data set consisting of all naturalized streamflow for the region available from various sources such as USGS and US Army Corps of Engineers. The feasibility of implementing this recommendation is being investigated.

[Soil_Moisture]

Figure 7-1.  Soil Moisture Measurement Location for North-South Transect in the Vicinity of 96W Longitude.


[MOLTS]

Figure 7-2.  Model Location Time Series (MOLTS) Sites from NCEP/Eta Regional Model Within Three Degrees Longitude of 96W from 20N to 50N Latitude.