David T. Ho

Adjunct Senior Research Scientist
Lamont-Doherty Earth Observatory
Geochemistry
61 Route 9W - PO Box 1000
Palisades
NY
10964-8000
US
Fields of interest: 
Air-water gas exchange, tracer oceanography, transport in continental waters

To assess how human impact will affect the natural environment, we need to understand the relevant environmental processes. I have focused my studies on transport processes in natural systems (atmosphere, oceans, lakes, rivers and groundwater), using natural and anthropogenic tracers.

Tracers, whether they are of natural or anthropogenic origin, have the potential to be valuable tools for studies of the dynamics of the atmosphere and natural water systems. The tracer techniques that I have employed could be divided into two categories: 1) transient tracers, which are like 'dyes' with known delivery rates to the environment (CFCs, SF6), and 2) deliberate tracers, which are purposefully released into water bodies (SF6, N2O, 4He, 3He, florescent dyes).

I'm currently working in the following areas: Quantifying the effect of environmental variables on air-water gas exchange, developing of tracers for ocean mixing and circulation, and investigating transport and mixing in continental waters.

Some of my projects include:

  • Development of SF6 as a transient tracer for ocean circulation
  • Develop SF5CF3 as a deliberate tracer for ocean mixing
  • Air-Sea Gas Exchange investigations as part of SOLAS (Surface-Ocean Lower-Atmospheric Studies)
  • Studying sheetflow in the Florida Everglades
  • Studying transport and air-water gas exchange in the Hudson River Estuary

 

Education
List of degrees from highest to lowest:
Ph.D.
Columbia University
2001
M.Phil.
Columbia University
2000
M.A.
Columbia University
1997
B.A.
Columbia University
1994
Selected Publications: 
Advances in Quantifying Air-Sea Gas Exchange and Environmental Forcing, Wanninkhof, R.; Asher, W. E.; Ho, D. T.; Sweeney, C.; McGillis, W. R. , Annual Review of Marine Science, Volume 1, p.213-244, (2009), DOI 10.1146/annurev.marine.010908.163742

Rain-induced turbulence and air-sea gas transfer, Zappa, C. J.; Ho, D. T.; McGillis, W. R.; Banner, M. L.; Dacey, J. W. H.; Bliven, L. F.; Ma, B.; Nystuen, J. , Journal of Geophysical Research-Oceans, Jul 9, Volume 114, p.-, (2009), Doi 10.1029/2008jc005008

Degradation rates of CFC-11, CFC-12 and CFC-113 in anoxic shallow aquifers of Araihazar, Bangladesh, Horneman, A.; Stute, M.; Schlosser, P.; Smethie, W.; Santella, N.; Ho, D. T.; Mailloux, B.; Gorman, E.; Zheng, Y.; van Geen, A. , Journal of Contaminant Hydrology, Apr 4, Volume 97, Issue 1-2, p.27-41, (2008), DOI 10.1016/j.jconhyd.2007.12.001

Use of SF5CF3 for ocean tracer release experiments, Ho, D. T.; Ledwell, J. R.; Smethie, W. M. , Geophysical Research Letters, Feb 19, Volume 35, Issue 4, p.-, (2008), Doi 10.1029/2007gl032799

Widespread elevated atmospheric SF6 mixing ratios in the Northeastern United States: Implications for groundwater dating, Santella, N.; Ho, D. T.; Schlosser, P.; Stute, M. , Journal of Hydrology, Jan 30, Volume 349, Issue 1-2, p.139-146, (2008), DOI 10.1016/j.jhydrol.2007.10.031

An SF6 Tracer Study of the Flow Dynamics in the Stockton Deep Water Ship Channel: Implications for Dissolved Oxygen Dynamics, Schmieder, P.J.; Ho, D.T.; Schlosser, P; Clark, J.F.; Schladow, S.G. , Estuaries and Coasts, Volume 31, p.14, (2008), 10.1007/s12237-008-9093-0

Degradation rates of CFC-11, CFC-12 and CFC-113 in anoxic shallow aquifers of Araihazar, Bangladesh, Horneman, A.; Stute, M.; Schlosser, P.; Smethie, W.; Santella, N.; Ho, D. T.; Mailloux, B.; Gorman, E.; Zheng, Y.; van Geen, A. , Journal of Contaminant Hydrology, Apr 4, Volume 97, Issue 1-2, p.27-41, (2008), DOI 10.1016/j.jconhyd.2007.12.001

The combined effect of rain and wind on air-water gas exchange: A feasibility study, Ho, D. T.; Veron, F.; Harrison, E.; Bliven, L. F.; Scott, N.; McGillis, W. R. , Journal of Marine Systems, Jun, Volume 66, Issue 1-4, p.150-160, (2007), DOI 10.1016/j.jmarsys.2006.02.012

Environmental turbulent mixing controls on air-water gas exchange in marine and aquatic systems, Zappa, C. J.; McGillis, W. R.; Raymond, P. A.; Edson, J. B.; Hintsa, E. J.; Zemmelink, H. J.; Dacey, J. W. H.; Ho, D. T. , Geophysical Research Letters, May 17, Volume 34, Issue 10, p.-, (2007), Doi 10.1029/2006gl028790

Comparison of SF6 and fluorescein as tracers for measuring transport processes in a large tidal river, Ho, D. T.; Schlosser, P.; Houghton, R. W.; Caplow, T. , Journal of Environmental Engineering-Asce, Dec, Volume 132, Issue 12, p.1664-1669, (2006), Doi 10.1061/(Asce)0733-9372(2006)132:12(1664)

Measurements of air-sea gas exchange at high wind speeds in the Southern Ocean: Implications for global parameterizations, Ho, D. T.; Law, C. S.; Smith, M. J.; Schlosser, P.; Harvey, M.; Hill, P. , Geophysical Research Letters, Aug 25, Volume 33, Issue 16, p.-, (2006), Doi 10.1029/2006gl026817

Seasonal variability and long term trends of chlorofluorocarbon mixing ratios in the unsaturated zone, Santella, N.; Schlosser, P.; Smethie, W. M.; Ho, D. T.; Stute, M. , Environmental Science & Technology, Jul 15, Volume 40, Issue 14, p.4414-4420, (2006), Doi 10.1021/Es052376o

Effect of tides on solute flushing from a strait: Imaging flow and transport in the East River with SF6, Caplow, T.; Schlosser, P.; Ho, D. T.; Enriquez, R. C. , Environmental Science & Technology, Sep 1, Volume 38, Issue 17, p.4562-4571, (2004)

Influence of rain on air-sea gas exchange: Lessons from a model ocean, Ho, D. T.; Zappa, C. J.; McGillis, W. R.; Bliven, L. F.; Ward, B.; Dacey, J. W. H.; Schlosser, P.; Hendricks, M. B. , Journal of Geophysical Research-Oceans, Jul 1, Volume 109, Issue C8, p.-, (2004), Doi 10.1029/2003jc001806

Tracer study of mixing and transport in the upper Hudson River with multiple dams, Caplow, T.; Schlosser, P.; Ho, D. T. , Journal of Environmental Engineering-Asce, Dec, Volume 130, Issue 12, p.1498-1506, (2004), Doi 10.1061/(Asce)0733-9372(2004)130:12(1498)

Transport in the Hudson estuary: A modeling study of estuarine circulation and tidal trapping, Hellweger, F. L.; Blumberg, A. F.; Schlosser, P.; Ho, D. T.; Caplow, T.; Lall, U.; Li, H. H. , Estuaries, Jun, Volume 27, Issue 3, p.527-538, (2004)

Distribution of atmospheric SF6 near a large urban area as recorded in the vadose zone, Santella, N.; Ho, D. T.; Schlosser, P.; Stute, M. , Environmental Science & Technology, Mar 15, Volume 37, Issue 6, p.1069-1074, (2003), Doi 10.1021/Es0156993

Transport dynamics in a sheltered estuary and connecting tidal straits: SF6 tracer study in New York Harbor, Caplow, T.; Schlosser, P.; Ho, D. T.; Santella, N. , Environmental Science & Technology, Nov 15, Volume 37, Issue 22, p.5116-5126, (2003), Doi 10.1021/Es034198+

Determination of longitudinal dispersion coefficient and net advection in the tidal Hudson River with a large-scale, high resolution SF6 tracer release experiment, Ho, D. T.; Schlosser, P.; Caplow, T. , Environmental Science & Technology, Aug 1, Volume 36, Issue 15, p.3234-3241, (2002), UNSP ES015814+

Atmospheric SF6 near a large urban area, Ho, D. T.; Schlosser, P. , Geophysical Research Letters, Jun 1, Volume 27, Issue 11, p.1679-1682, (2000)

On mechanisms of rain-induced air-water gas exchange, Ho, D. T.; Asher, W. E.; Bliven, L. F.; Schlosser, P.; Gordan, E. L. , Journal of Geophysical Research-Oceans, Oct 15, Volume 105, Issue C10, p.24045-24057, (2000)

Variability in atmospheric chlorofluorocarbons (CCl3F and CCl2F2) near a large urban area: Implications for groundwater dating, Ho, D. T.; Schlosser, P.; Smethie, W. M.; Simpson, H. J. , Environmental Science & Technology, Aug 15, Volume 32, Issue 16, p.2377-2382, (1998)

The effect of rain on air-water gas exchange, Ho, D. T.; Bliven, L. F.; Wanninkhof, R.; Schlosser, P. , Tellus Series B-Chemical and Physical Meteorology, Apr, Volume 49, Issue 2, p.149-158, (1997)

Gas exchange, dispersion, and biological productivity on the west Florida shelf: Results from a Lagrangian tracer study, Wanninkhof, R.; Hitchcock, G.; Wiseman, W. J.; Vargo, G.; Ortner, P. B.; Asher, W.; Ho, D. T.; Schlosser, P.; Dickson, M. L.; Masserini, R.; Fanning, K.; Zhang, J. Z. , Geophysical Research Letters, Jul 15, Volume 24, Issue 14, p.1767-1770, (1997)

Gas Transfer Velocities for Sf6 and He-3 in a Small Pond at Low Wind Speeds, Clark, J. F.; Schlosser, P.; Wanninkhof, R.; Simpson, H. J.; Schuster, W. S. F.; Ho, D. T. , Geophysical Research Letters, Jan 15, Volume 22, Issue 2, p.93-96, (1995)