California
Applications Program (CAP) - California
Contributions
to Decision Support: Tools and Resource Forecasts
- US
Streamflow Forecasts: Based on interannual and interdecadal
predictors, CAP researchers create streamflow forecasts considering
the variability of streamflow and the anticipated water year
atmospheric conditions. Historical daily flow records from over
1200 streamgaging stations across the US were used to compute
flood statistics and winter and spring seasonal averages for
each stations period of record. Historical conditioning of flow
terciles by ENSO and PDO status were analyzed and then used
together with summertime predictions of the following year’s
ENSO and PDO conditions to develop a streamflow forecast. (http://meteora.ucsd.edu/cap/flow2003_fcast.html)
- Forecasts
of temperature and precipitation extremes: Using observed
and model predictors, CAP researchers developed a statistical
downscaling scheme to produce useful seasonal forecasts of climate
extremes, such as temperature and precipitation. Energy, water
and fire resource managers use the extreme forecasts in planning
for critical or emergency situations, such as increased power
demand or increased threat of flood or fire.
- Western
US seasonal snowpack forecasts: Using summer and fall
climate conditions, CAP researchers developed a principal component
analysis method for predicting April 1 snowpack over the western
US. Snowpack, as measured on April 1, is the primary source
of warm-season streamflow for most of the western US and thus
represents an important source of water supply. (http://tenaya.ucsd.edu/~dettinge/pdosnow.pdf)
- Wildfire
forecasts for the western US: For lead times of a season
to two years, CAP researchers have developed statistical forecasts
of seasonal area burned based on drought severity indices. For
the past two years, these forecasts have successfully predicted
many features of the western US wildfire season. Fire managers
use these early forecasts for requesting supplemental resources
and making decisions about temporary fire suppression personnel.
(http://meteora.ucsd.edu/cap/fire_forecast2003.html)
Engaging stakeholders
- Northern
California water resource prediction/management (Folsom):
Working with Staff of Central Valley Operations of the Bureau
of Reclamation and NOAA’s regional River Forecast Center
in Sacramento, CAP researchers provide streamflow simulations
for the operational management of the Folsom Lake Reservoir.
Demonstration of the feasibility and utility of climate-hydrology
forecasting and water resources management is accomplished by
inter comparing retrospective reservoir operations under: (1)
current operational practice, (2) integrated forecast-control
operation using climate forecasts based on historical/climatological
information and (3) integrated forecast-control operation using
climate forecasts based on global climate model simulations.
(http://www.hrc-web.org/FOLSOM/)
- Medium
Range Forecasts for city of San Francisco: For the
City of San Francisco / Hetch Hetchy water/power system, CAP
researchers have averaged and scaled 12 individual 15-day forecasts
of precipitation and temperature from the current NCEP medium-range
forecast ensemble. The forecasts are rescaled from the global
grid of the MRF weather model (roughly 2 degrees of latitude
by 2 degrees of longitude), and from the 850 millibar pressure
level in the atmosphere, to be equivalent to the temperatures
routinely observed by the Tuolumne Meadows SNOWTEL site. Precipitation
is scaled to have the same monthly means as the Hetch Hetchy
precipitation station. These rescaled forecasts were designed
to be suitable for input to statistical predictors of Hetch
Hetchy inflows. (http://tenaya.ucsd.edu/~dettinge/hetchy/)
- Web
pages: Public web pages communicate with stakeholders
on issues of immediate interest such as drought, wildfire, snowfall,
Santa Ana and May Gray/June gloom conditions. Web pages also
provide data and forecast resources for stakeholders. CAP actively
maintains and updates two main web informational sources: (1)
the California Applications Program web site (http://meteora.ucsd.edu/cap)
and (2) the California Assessment for the United States Global
Change Research Program: Preparing for a Changing Climate (http://tenaya.ucsd.edu/~meyer/calif_usgcrp.html)
- Stakeholder
briefings: CAP researchers respond to numerous requests
for specific briefings on issues of climate conditions, forecasts
and long-range planning. For example, a recent presentation
was made for the USBR Yuma desalinization plant (Department
of Water Resources) concerning flood and drought possibilities
for the next 30 years. Also, a plenary talk briefed the 2003
Southwest Drought Summit on current and changing southwest climate
conditions. In addition, the Mojave Water Agency requested information
on the most suitable historic periods for testing its long-term
water-resource management alternatives. Recently, many stakeholders,
including Ventura and San Diego counties, have expressed interest
in climatic periods suitable for analyzing total maximum daily
loads, as this is important to water quality.
Influencing operations and policy
- CALFED
and climate change in California: CAP researchers engaged
the interests of CALFED, a CALifornia FEDeration Program of
more than 20 state and federal agencies working with local communities
to develop and implement plans to restore ecological health
and improve water management for the San Francisco Bay-Delta
system over the next 30 years. This system provides water for
2/3 of the state of California (22 million people), irrigation
supplies for $27 billion in agriculture (45% of the nation’s
produce) and is a primary water source for California’s
trillion-dollar economy. The ecosystem and its freshwater supply
are in jeopardy because of freshwater diversions. CAP is working
with CALFED to integrate climate change and variability into
its restoration plans so that they will be able to accommodate
California’s highly variable climate. (http://meteora.ucsd.edu/cap/calfed_climate.html)
- Real-time
climate monitoring for wildfire: CAP’s CEFA (Program
for Climate, Ecosystem and Fire Applications), has developed
a web-based near-real-time climate monitoring section that offers
10 and 30 day anomaly maps of remote automatic weather station
and lightning strikes over the west. Developed for stakeholders,
this site offers previously unavailable information to land
managers and fire weather forecasters. (http://cefa.dri.edu/Assessment_Products/ClimMon/RawsReanalanoms.html)
- Ventura
Basin ground-water management: Working with the United
Water Agency, CAP researchers are developing a ground-water/surface-water
model that incorporates long-range (seasonal) forecasts to address
management issues. Ensembles of hindcast climate simulations
from 1950 to 1998, by three different climate-prediction model
runs, have been used to force a calibrated model of ground-water/surface-water
conditions in the Santa Clara-Calleguas basin of southern California.
(http://meteora.ucsd.edu/cap/ventura.html)
Significant additions to knowledge
- Climate
change impacts on California: CAP research alerted
the California hydrologic community that even modest climate
changes could mean a significant decrease in snowmelt, which
was unexpected. Simulated snowpack under warmed conditions depicts
a severe loss of snow as indicated by changes in the snow water
equivalent (SWE). By 2030, under the "business-as-usual"
scenario, temperature is projected to rise about 0.6 °C,
resulting in a minor decrease in April snowpack at lower elevations.
However, by 2060 a temperature rise of 1.6 °C results in
a loss of one-third of the total snowpack. This loss is focused
in mid to lower elevations since the snowpack there is more
sensitive to temperature changes than at higher, colder elevations.
By 2090, a projected temperature increase of 2.1 °C results
in a loss of about half of the average April snowpack storage,
with greatest losses in the northern headwaters. Spring runoff
is reduced by 5.6 cubic km, with associated increases in winter
flood peaks. (http://meteora.ucsd.edu/cap/hydro_glwarming.html)
- Mosquito
abundance and seasonal moisture: Working with a group
led by Bill Reisen, Arbovirus Research Station, Bakersfield,
CA, CAP researchers are finding links between seasonal moisture
indices and mosquito abundance. With the expected near-future
arrival of West Nile virus in California, the ability to anticipate
mosquito abundances has taken on increased public interest.
There has been considerable interannual variability in mosquito
abundance, part of which is correlated across the entire state
of California. Summer mosquito numbers correlate positively
with moisture accumulation, as indicated by precipitation, streamflow
and snow water content. Prediction of summer mosquito abundance
from prior winter moisture variables may provide a useful look
ahead at several months lead-time. (http://meteora.ucsd.edu/cap/calif_health.html)
- Building
a climate observational capacity: CAP has initiated
several projects towards building climate observational capacity
in California and the western US.
- CAP
is part of a multi-disciplinary, multi-agency team installing
an upgraded set of meteorological, snow and stream instruments
in the Sierra Nevada. These instruments are critical tools
for collecting information leading to further understanding
of the large interannual and lower frequency climate variability
in the Sierra and to learn more about potentially large
impacts due to climate change. Historical measurements of
key physical elements in the mountain snow zone are sparse
and not complete, so the nature of recent, and future, changes
and the processes that drive them are not well understood.
A real-time monitoring system will help greatly to improve
this understanding and better observe climate variability
and change as they occur. (http://meteora.ucsd.edu/cap/snow_monitor.html)
- CAP
is also part of an effort to use wireless communication
to provide real-time detailed weather observations. This
hydro-meteorological effort is located in the coastal sagebrush
of the Santa Margarita Ecological Reserve (SMER), north
of San Diego in southern California. Towers containing instruments
have been established at strategic locations in SMER to
allow for detailed monitoring of air and water mass transfer.
(http://tenaya.ucsd.edu/~meyer/smer_hydromet.pdf)
- CAP
has assumed the role of maintaining the lilac and honeysuckle
records from the Western Regional Phenological Network (WRPN).
This network (established in 1957 for lilac and 1968 for
honeysuckle), shows key phonological phases have fluctuated
over the last 4-5 decades indicating warmer-than-normal
springs which may be an expression of natural variability
or a symptom of global warming. (http://meteora.ucsd.edu/cap/lilac.html)
- Medium-range
forecast (MRF) archive: The CAP historical MRF ensemble
project uses a single, unchanging, global atmospheric model
to make a set of daily medium range (0-14 day) forecasts over
a long historical period. This MRF history is needed to allow
objective, quantitative assessments of forecast skill and the
predictability of various kinds of weather events. For every
day from 1979 to present, CAP is making an ensemble of 10 forecasts.
The model employed is the National Centers for Environmental
Prediction (NCEP)'s MRF model (Reanalysis II version). To produce
an ensemble of 10 forecasts we have adopted the NCEP "breeding"
procedure to make 5 pairs of positively and negatively perturbed
initial conditions for each of the individual forecast runs.
(http://meteora.ucsd.edu/cap/hindcast.html)
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