2011 - Cooperative Institute for Research in Environmental Sciences ...

Milestone 1. Quantify the impact of sudden stratospheric
warmings (SSW) on the upper atmosphere. Recent observations
suggest that SSW impact the dynamics and
electrodynamics of the lower thermosphere, and change
the diurnal variation of total electron, which is an important
component of space weather. The recently developed
Whole Atmosphere Model (WAM) simulates SSW naturally,
so will be used to quantify their impact on the thermosphere
and ionosphere.
A whole atmosphere
model has
been used to simulate
the changes in
the global atmosphere
dynamics
and electrodynamics
during the
January 2009 sudden
stratospheric
warming (SSW).
In a companion
paper, it has been
demonstrated that
the neutral atmosphere
response to
the 2009 warming
can be simulated
with high fidelity
and can be forecast
several days
ahead. The 2009
warming was a
large event with
the polar stratospherictemperature
increasing by
70 K. The neutral
dynamics from the
whole atmosphere model (WAM) was used to simulate
the response of the electrodynamics. The WAM simulation
predicted a substantial increase in the amplitude of
the eight-hour ter-diurnal tide in the lower thermosphere
dynamo region in response to the warming, at the expense
of the more typical semi-diurnal tides. The increase in the
ter-diurnal mode had a significant impact on the diurnal
variation of the electrodynamics at low latitude. The
changes in the winds in the dayside ionospheric E region
increased the eastward electric field early in the morning,
and drove a westward electric field in the afternoon. The
initial large increase in upward drifts gradually moved
to later local times, and decreased in magnitude. The
change in the amplitude and phase of the electrodynamic
response to the SSW is in good agreement with observations
from the Jicamarca radar. The agreement of the
electrodynamics with observations serves to validate the
whole atmosphere dynamic response. Since WAM can
forecast the neutral dynamics several days ahead, the
simulations indicate that the electrodynamic response can
also be predicted.
Product: Fuller-Rowell, T, H Wang, R Akmaev, F Wu, T
Fang, M Iredell, and A Richmond (2011), Forecasting the
dynamic and electrodynamic response to the January 2009
sudden stratospheric warming, Geophys. Res. Lett., 38,
L13102, doi:10.1029/2011GL047732.
AMOS-04 Observing Facilities,
Campaigns and Networks
n GMD-02 Surface Radiation Network
n PSD-10 Cloud and Aerosol Processes
n PSD-11 Water Cycle
n GSD-04 Unmanned Aircraft Systems
GMD-02SurfaceRadiationNetwork
FEDERAL LEAD: JOSEPH MICHALSKY
CIRES LEAD: GARY HODGES
NOAA Goal 2: Climate
Project Goal: Collect long-term, researchquality,
up-welling and down-welling
broadband solar and infrared radiation
data at seven U.S. sites. Collect long-term,
broadband ultraviolet radiation data
to evaluate variations in the erythemal
doses. Collect long-term, spectral filter
data to measure column aerosol optical
depth and cloud optical depth. Collect
cloud cover data to assess the effect of
clouds on the surface radiation budget.
Milestone 1. Using SURFRAD databases,
complete and publish an analysis
of spectral albedo at the Table Mountain,
Colorado, SURFRAD station and
present the results in conferences.
To determine surface spectral albedo
requires measuring the incoming
(downwelling) and reflected (upwelling)
irradiance over a range of
wavelengths. Reflected values are divided
by the corresponding incoming
values to give albedo. To measure the
incoming data, we continue to operate
a Multi-Filter Rotating Shadowband
Radiometer (MFRSR) at our Table
View of the albedo
tower located at Table
Mountain, approximately
10 miles north
of Boulder, Colo.
Mounted on the
tower is the head of an
MFRSR. Other instruments
are radiometers
measuring reflected
UV-B and reflected
Photosynthetically Active
Radiation (PAR).
Mountain, Boulder, Colo., Surface Radiation Budget Network
(known as SURFRAD) site. For the reflected data,
we have mounted an MFRSR sensor head in the inverted
position on a 10-m tower located approximately 100 feet
north of the MFRSR. For accurate albedo calculation, it is
important that both instruments undergo routine calibrations
linked to a common source. Instrument calibrations
are performed on a regular basis using a standard lamp.
We have presented spectral albedo results at three
meetings: 1) The annual Atmospheric System Research
Science Team Meeting in Bethesda, Maryland; 2) The
biennial Baseline Surface Radiation Network meeting in
Queenstown, New Zealand; and 3) the 13th Conference on
Atmospheric Radiation in Portland, Ore.
Collecting the necessary data for determining spectral
albedo at Table Mountain is part of an ongoing, long-term
measurement program. These data have been attracting
the interest of other researchers. Most recently, NASA has
requested these data for use in validating the Moderate
Resolution Imaging Spectroradiometer (MODIS), a key
instrument aboard the Terra and Aqua satellites.
CIRES Annual Report 2011 101