5. Current Research
In this section, we highlight some recent research achievements of
the Division. More detailed summaries are contained in the Division's
bi-annual Reports.
Environmental Monitoring Branch
New Vegetation Products Transitioned to Operations
A VCI product that measures the condition of local vegetation world-wide
and a Global Vegetation Fraction (GVF) that provides data on the fraction
of green vegetation in a global array of grid boxes have been successfully
transitioned from research to operations in 2004. Both products are based
on AVHRR observations and are produced weekly.
The VCI indicates whether the health, vigor and amount of vegetation in
a particular area are above normal or below normal for that time of year.
Together with satellite observations of land surface temperatures, the VCI
can be used to monitor drought conditions globally.
The GVF shows how much of the land surface is covered with actively
growing vegetation. It is used in NWP Models to calculate the rates of
heat and moisture transfer from the surface to the atmosphere. An example
of the GVF for North America for June 16, 2003 is shown below.
Figure 6: Green Vegetation Fraction for the week of June 16, 2003.
Detection of Severe Drought in Horn of Africa
Using the AVHRR Vegetation Condition Index, SMCD scientists have
detected areas of extreme drought conditions in parts of Kenya, Ethiopia and
Somalia for the sixth year in a row. These conditions leave the region
with threats of starvation, water shortages, widespread crop losses and
disease outbreaks.
A New Capability: Automated Ice Cover Maps
SMCD has developed an algorithm to identify and map ice cover using
observations from GOES Imager and NOAA AVHRR. Ice distribution is
derived over seas and oceans surrounding North America as well as
over internal water bodies (lakes, reservoirs, etc.).
The retrieval results are validated against snow and ice cover maps
generated within snow and ice maps prepared at the NOAA National Ice
Center (NIC). Ice cover will be added to currently operational North
America automated snow cover maps after a year-round validation of
the product is completed.
Figure 8: Comparison of snow/ice maps produced using the new SMCD
automated algorithm (left) and the NOAA Interactive Multisensor Snow
and Ice Mapping System (IMS) for December 27, 2004.
