GSAAS Events: DC-AMS joint meeting
February 22, 2011
University of Maryland, College Park

This was a joint meeting of the DC AMS chapter, with members presenting research from University of Maryland, GSSAS, George Mason University, and University of Maryland Baltimore County. 

Notes transcribed by Cassie Stearns. 

Opening Social 
Pizza and other light refreshments were served prior to the beginning of the meeting. Members of all the above groups were invited to mingle and meet one another. 

Welcome and Announcements
Opening remarks were by Andrea, the President of DC-AMS. Andrea asked us to consider becoming officers of DC-AMS, or at least members. Student membership for the year is $5.00. They will be publishing a newsletter soon, and will be participating in a number of upcoming science fairs at schools in Maryland, DC, and Virginia. 

Presentations
Research by members of all four university groups and the DC-AMS was presented. The following were presentations and highlights of the research: 

Jefferey W. Steher –UMD
“Welcome to Maryland” – an overview of the research being pursued at UMD. 
•	CO modeling – current models are having trouble capturing low-level sources
•	WRF modeling – fixing problems with CO also improves weather forecasts
•	Ozone – controls on the NOx effects
•	El Nino: dust bowl and wet period mechanisms from each ocean and effects on North America
•	LETKF – reducing errors from long-term iterations and a “learning system”. 
•	Climate change and floods
•	Thunderstorms and pollution distribution
•	Collaborative efforts such as ozone hole monitoring in the polar vortex 
o	Air is not as isolated in the vortex as we may think – a modeling study presented showed how parcels of air may migrate from the center of the vortex to the outside while the vortex structure remains intact!

Anthony Santorelli – UMD
Difference between air-sea turbulent fluxes over the Atlantic Ocean
•	Measurement of Sensible Heat and Latent Heat at 10 m depth
•	Why are large difference seen in SH and LH for different models?
o	Data comes from different sources (different physical places, satellite vs. in situ sensors, etc.)
o	Formulas are similar, but some assumptions change by calculation method
•	Q-term methods used in this study
•	Differences measured between IFREMER-WHOL 1996-2005
•	Specific Humidity found to be most important variable for generating differences
•	Air temperature, however,  had the most uncertainty 

Adrian Flores – HU
Radiative Forcing and Thermodynamic Impact of Aerosols during AEROSE Campaign
o	AEROSE is an oceanographic cruise in the tropical North Atlantic for research on the Saharan Air Layer (SAL).
o	23 degrees W longitude is main focus
o	Microtops sun photometer used 
o	Angstrom coefficients measured: > 1 = smoke, ~0.2 = dust
o	Huge dust plume passed through from May 12-15, 2007
o	SAL has multiple layers during dust event from wakes and eddies
o	High AOD from Microtops coincide with SAL filaments seen aloft
o	Warming observed just above the marine boundary layer – due to SAL aloft? (Radiative transfer model will be used to verify)

Jian Li – George Mason 
On modeling the sea surface temperature and diurnal cycle
o	Sea Surface Temperature diurnal variations connected to diurnal mixed layer
o	Top 2 m of ocean warmed
o	Want to add a sublayer into ocean models (to 3 m depth)
o	Trying parameterizations to see what works best
o	3-hour coupling used
o	Pulled diurnal signal from SST, but the diurnal signal is NOT constant 
o	Control study underestimated daily change amplitude
o	Want to look at effects on MJO life cycle from diurnal forcing.

	Q: Do models’ parameterization take into account surface roughness of ocean?
	A: The setup of the model is a black-box; it is unknown
  
Gergely Douglass – UMBC
Development of an instrument to measure aerosols from satellite
o	Instrument development: a polarization nephelometer
o	Looking at light scattering of aerosols in a new way
o	Want instrument for in-situ experiments
o	Instrument measures the scatter matrix of aerosols with different polarizations from the laser
o	Pictures of the laser beam are taken form the side 
o	Change laser polarization (and wavelength?) and angle
o	Intended for use in the DEVOTE campaign for satellite validation
o	This instrument will take in situ samples from 2 airplanes flown in concert

Manisha Ganeshan – UMD
Working with WRF model and making improvements by testing heating schemes
o	Look at warm peak resolution for models
o	WRF model used (3-ensamble mode)
o	NCEP stage N observations were used
o	Course and medium resolution did not show peaks at the right time; fine resolution could capture afternoon convective peak
o	This was a very minor improvement
o	Spatial errors make things slightly better for finer resolution
o	Problem encountered: cumulus scheme does not properly simulate CIN
o	Could CIN be connected to evolution of the boundary layer as a fix?
o	Explicit resolution was shown to improve forecast skill

Mayra Oyola – HU
Validation of the Wind Cube lidar on AEROSE campaign
o	Wind cube is a Doppler wind lidar by Leosphere
o	The cube scans 15 degrees with 30s / profile, 4 lines of sight scanned sequentially
o	Wind cube is a land-based instrument – must account for changes at sea
o	Must correct for the motions of the ship to translate measured wind speed to real wind speed
o	Comparison with RS-92 radiosondes for validation – results were good
o	Marine boundary layer was captured by lidar

Erik Swonson – George Mason
Sustained variability in response to ENSO
o	Are subseasonal changes in tropical forcing important to seasonal mean response?
o	There are nonlinear components to the response
o	AGCM model used (NCAR’s CAM 4.0)
o	Anomaly shown from 26-year AMP climatology
o	Vertically integrated diabatic heating calculated
o	Then 300 hPa pressure map (connected to shifts in storm track) and 200 hPa heights map were examined
o	Sustained events have larger mean forcing
o	There is a lag in response
o	Thresholds of event length are sensitive
o	Results need to be reproduced to verify findings 

Debra Kollonige – UMBC
Impacts of upper tropospheric conditions for air quality
o	High ozone events occur during periods of low local production (ex. Winter)
o	Stratospheric air injected into troposphere during tropopause folds
o	Want to know what happens near jet stream/streak
o	Q-vectors were calculated to show mean up/down motions
o	Have direct and indirect circulations set up to create fold; see this in frontogenisis (high potential vorticity regions)
o	Possible wrap-around effect: 2 upper-level sources of ozone form from fronto gensis for 1 location at surface

Post-Presentations
After the presentations, the floor was opened for general questions and socialization. We hope to continue this event in the future. Thank you to our presenters and those who attended!