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Climate And Nitrogen Controls On The Geography And Timescales Of Terrestrial Biogeochemical Cycling, David S. Schimel, Rob Braswell, R Mckeown, Dennis S. Ojima, W J. Parton, W Pulliam
Climate And Nitrogen Controls On The Geography And Timescales Of Terrestrial Biogeochemical Cycling, David S. Schimel, Rob Braswell, R Mckeown, Dennis S. Ojima, W J. Parton, W Pulliam
Earth Sciences
We used the terrestrial ecosystem model “Century” to evaluate the relative roles of water and nitrogen limitation of net primary productivity, spatially and in response to climate variability. Within ecology, there has been considerable confusion and controversy over the large-scale significance of limitation of net primary production (NPP) by nutrients versus biophysical quantities (e.g., heat, water, and sunlight) with considerable evidence supporting both views. The Century model, run to a quasi-steady state condition, predicts “equilibration” of water with nutrient limitation, because carbon fixation and nitrogen fluxes (inputs and losses) are controlled by water fluxes, and the capture of nitrogen into …
Extracting Ecological And Biophysical Information From Avhrr Optical Data: An Integrated Algorithm Based On Inverse Modeling, Rob Braswell, David S. Schimel, Jeffrey L. Privette, B Moore, W J. Emery, E W. Sulzman, A T. Hudak
Extracting Ecological And Biophysical Information From Avhrr Optical Data: An Integrated Algorithm Based On Inverse Modeling, Rob Braswell, David S. Schimel, Jeffrey L. Privette, B Moore, W J. Emery, E W. Sulzman, A T. Hudak
Earth Sciences
Satellite remote sensing provides the only means of directly observing the entire surface of the Earth at regular spatial and temporal intervals. Key Earth system variables can be obtained from satellite data by integrating appropriate processing, interpretation, and modeling. For example, the amount of photosynthetically active radiation absorbed by plants (APAR) and land surface albedo can be inferred from remotely sensed optical measurements. Radiative transfer model inversion exploits the dependence of reflectance on the relative source-sensor geometry to estimate surface parameters. In contrast, geometrical effects are suppressed in most other approaches. We present an algorithm for the retrieval of fractional …
Modeling Of The Processing And Removal Of Trace Gas And Aerosol Species By Arctic Radiation Fogs And Comparison With Measurements, M H. Bergin, S N. Pandis, C Davidson, J L. Jaffrezo, Jack E. Dibb, A G. Russell, H D. Kuhns
Modeling Of The Processing And Removal Of Trace Gas And Aerosol Species By Arctic Radiation Fogs And Comparison With Measurements, M H. Bergin, S N. Pandis, C Davidson, J L. Jaffrezo, Jack E. Dibb, A G. Russell, H D. Kuhns
Earth Sciences
A Lagrangian radiation fog model is applied to a fog event at Summit, Greenland. The model simulates the formation and dissipation of fog. Included in the model are detailed gas and aqueous phase chemistry, and deposition of chemical species with fog droplets. Model predictions of the gas phase concentrations of H2O2, HCOOH, SO2, and HNO3 as well as the fog fluxes of S(VI), N(V), H2O2, and water are compared with measurements. The predicted fluxes of S(VI), N(V), H2O2, and fog water generally agree with measured …
Recent Climate Anomalies And Their Impact On Snow Chemistry At South Pole, 1987 - 1994, Jack E. Dibb, Sallie I. Whitlow
Recent Climate Anomalies And Their Impact On Snow Chemistry At South Pole, 1987 - 1994, Jack E. Dibb, Sallie I. Whitlow
Earth Sciences
Three 2-m deep snowpits sampled at South Pole in 1994 provide detailed (2-cm resolution) profiles of the concentrations of soluble ionic species for the period 1987 - 1994. The most prominent feature is a large concentration spike of SO4 = in snow deposited in 1992 reflecting fallout from the eruptions of Pinatubo and Hudson in 1991. Concentrations of MSA and values of the MSA/(non-sea-salt SO4 =) ratio are elevated for about three years centered on the prominent volcanic signal. These changes appear to be due to the extended 1991 - 1993 El Nino. The overlapping effects of the volcanic eruptions …
Asian Influence Over The Western North Pacific During The Fall Season: Inferences From Lead 210, Soluble Ionic Species And Ozone, Jack E. Dibb, R. Talbot, Anthony Klemm, G L. Gregory, H B. Singh, J D. Bradshaw, S T. Sandholm
Asian Influence Over The Western North Pacific During The Fall Season: Inferences From Lead 210, Soluble Ionic Species And Ozone, Jack E. Dibb, R. Talbot, Anthony Klemm, G L. Gregory, H B. Singh, J D. Bradshaw, S T. Sandholm
Earth Sciences
Aerosol samples collected over the western Pacific during the NASA/Global Tropospheric Experiment Pacific Exploratory Mission (PEM-West A) expedition (September–October 1991) revealed mean 210Pb concentrations in the free troposphere in the 5–10 fCi m−3 STP range. Most soluble ionic aerosol-associated species were near detection limits [≪40 parts per trillion by volume (pptv)] in these same samples. The altitude distribution of O3 near Asia closely resembled that of 210Pb, while no relationship was found between the concentrations of O3 and 7Be. Free tropospheric air over the western Pacific was depleted in soluble aerosol-associated species but enriched …
Chemical Characteristics Of Continental Outflow From Asia To The Troposphere Over The Western Pacific Ocean During September-October 1991: Results From Pem-West A, R. Talbot, Jack E. Dibb, K I. Klemm, J D. Bradshaw, S T. Sandholm, D R. Blake, G W. Sachse, J E. Collins Jr, B J. Heikes, G L. Gregory, B E. Anderson, H B. Singh, D C. Thornton, J T. Merrill
Chemical Characteristics Of Continental Outflow From Asia To The Troposphere Over The Western Pacific Ocean During September-October 1991: Results From Pem-West A, R. Talbot, Jack E. Dibb, K I. Klemm, J D. Bradshaw, S T. Sandholm, D R. Blake, G W. Sachse, J E. Collins Jr, B J. Heikes, G L. Gregory, B E. Anderson, H B. Singh, D C. Thornton, J T. Merrill
Earth Sciences
An important objective of the Pacific Exploratory Mission-West A (PEM-West A) was the chemical characterization of the outflow of tropospheric trace gases and aerosol particles from the Asian continent over the western Pacific Ocean. This paper summarizes the chemistry of this outflow during the period September – October 1991. The vertical distributions of CO, C2H6, and NOxshowed regions of outflow at altitudes below 2 km and from 8 to 12 km. Mixing ratios of CO were ≈130 parts per billion by volume (ppbv), ≈1000 parts per trillion by volume (pptv) for C2H …
Atmospheric Sampling Of Supertyphoon Mireille With Nasa Dc-8 Aircraft On September 27,1991, During Pem-West A, G W. Sachse, R E. Newall, W Hu, Z X. Wu, H Akimoto, B E. Anderson, E V. Browell, G L. Gregory, G W. Sachse, M C. Shipman, A S. Bachmeier, A R. Bandy, D C. Thornton, D R. Blake, F Sherwood Rowland, J D. Bradshaw, J H. Crawford, D D. Davis, S T. Sandholm, W Brockett, L Degreef, D Lewis, D Mccormick, E Monitz, J E. Collins Jr, B J. Heikes, J T. Merrill, K K. Kelly, S C. Liu, Y Kondo, M Koike, C M. Liu, F Sakama, H B. Singh, Jack E. Dibb, R. Talbot
Atmospheric Sampling Of Supertyphoon Mireille With Nasa Dc-8 Aircraft On September 27,1991, During Pem-West A, G W. Sachse, R E. Newall, W Hu, Z X. Wu, H Akimoto, B E. Anderson, E V. Browell, G L. Gregory, G W. Sachse, M C. Shipman, A S. Bachmeier, A R. Bandy, D C. Thornton, D R. Blake, F Sherwood Rowland, J D. Bradshaw, J H. Crawford, D D. Davis, S T. Sandholm, W Brockett, L Degreef, D Lewis, D Mccormick, E Monitz, J E. Collins Jr, B J. Heikes, J T. Merrill, K K. Kelly, S C. Liu, Y Kondo, M Koike, C M. Liu, F Sakama, H B. Singh, Jack E. Dibb, R. Talbot
Earth Sciences
The DC-8 mission of September 27, 1991, was designed to sample air flowing into Typhoon Mireille in the boundary layer, air in the upper tropospheric eye region, and air emerging from the typhoon and ahead of the system, also in the upper troposphere. The objective was to find how a typhoon redistributes trace constituents in the West Pacific region and whether any such redistribution is important on the global scale. The boundary layer air (300 m), in a region to the SE of the eye, contained low mixing ratios of the tracer species O3, CO, C2H6, C2H2, C3H8, C6H6and CS2 …