GEOS-CHEM Near-Real-Time (NRT) Simulations
NOTE: You may encounter problems with INTERNET EXPLORER
using this site. We recommend that you use either NETSCAPE or MOZILLA.
Please report any bugs/comments to Lyatt Jaeglé (email@example.com).
NEW: Near real time comparison to
observations at three west coast sites.
Follow the new option above,
"Ground-station browser", to view real-time observations
of CO, ozone and NOy from the Jaffe research
compare them to the GEOS-CHEM NRT simulation! These observations are
made continuously at two sites: Cheeka Peak
(48.3 N, 124.6 W, 480 m) in Washington State and Mt. Bachelor
Observatory (43.8N, 121.7W, 2.7 km) in Oregon. We are also extracting
NRT results at Whistler Summit in Canada.
The maintenance of this web-site is made possible by funding
from the National Science Foundation under grant ATM 0238530.
QUICKSTART GUIDE to NRT simulation browser
Here you can view output from the daily near-real-time simulations
which are generated with the GEOS-CHEM
model. You can choose to plot timeseries data (CO, NOx,O3, HNO3, PAN,
acetone, sulfate, dust, sea-salt), columns (CO, NO2, HCHO, O3), or
chemical quantities (OH, NO2, NO).
Simply press the "Start NRT browser" button to see maps of the various
products calculated with the GEOS-CHEM chemical transport model. You
can then adjust the day, hour, tracer, latitude, longitude, altitude
and plot the results again. You also have the options of generating an
animation or a postscript file. The curtain display option together
with the 'Zonal Average' or 'Meridional Average' plot type allows you
to enter (latitude, longitude, altitude) along a proposed flighttrack
and then sample it along that flight track. All dates are indicated in
THE GEOS-CHEM Near-Real-Time (NRT) SIMULATIONS
We are producing daily
detailed ozone–aerosol–CO–CO2–methane simulations with the GEOS–CHEM
model. These GEOS–CHEM simulations are being generated at Harvard
University using the GEOS–4 first-look assimilated data product at
2° latitude by 2.5° longitude horizontal resolution and 55
vertical levels. The GEOS-4 meteorological assimilated fields are
generated at NASA's Global
Modeling and Assimilation Office (GMAO).
The simulations lag the present by only 2-3 days, and hence have been dubbed
"near-real-time", or NRT for short.
The GEOS–CHEM NRT
simulations serve 3 purposes:
- To monitor over the
course of ICARTT any large deviations between the aircraft observations
and our understanding of ozone and aerosol processes that may cause
alteration of flight plans,
- To provide
vertical shape information for NO2 and HCHO concentrations to support
near-real-time retrievals of SCIAMACHY column data for these two gases
(by Dalhousie University), and
- To generate
a set of preliminary findings by the end of ICARTT.
The NRT simulations
include our most detailed GEOS–CHEM representation of coupled nonlinear
ozone–NOx–VOC–aerosol chemistry [Park et al 2004], CO2
[Suntharalingam, 2004], and methane [Xiao et al 2004]. Anthropogenic
emissions in the United States will be from the EPA NEI 1999 inventory.
Fires in North American and Northern Asia will be included in the
simulation on the basis of MODIS satellite observations.
Output from the NRT
simulations are posted to this website (maintained by Lyatt
Jaeglé at the University of Washington) and consists of 3
different kinds of quantities:
- 3-D timeseries data
Ozone, NOx, PAN, PMN, HNO3, ACET sulfate, aerosol optical depths, black
columns of O3, NO2, HCHO
- Total CO
data saved along flight tracks
GEOS–CHEM chemical tracers
produced quantities: NO, OH, HO2
Personnel at Harvard
responsible for generating NRT simulations:
- Bob Yantosca
- Rynda Hudman
- Daniel Jacob
forecasting and near-real-time CTM analysis in support of INTEX–NA, D. J. Jacob, 2004.