54
8.M.P. Benbow
components as well as measurements of DMS in the atmosphere and
oceans.
Implications for the Terrestrial Environment
Coastal zones are difficult to define and may include areas of influence
from certain selected ecological factors that extend landward and seaward
from the seashore. The features representing each domain must be characteristic of that domain, such as the primary production of ocean areas
or the extent of rainforest in terrestrial regions. For the coastal regions,
the influence of land, air, and sea features affect all ecoystems.
Sulfur deposition encompasses both dry deposition and wet deposition ,
the former as gaseous and particulate deposition and the latter determined
by precipitation. Once emitted to the atmosphere, DMS is eventually
oxidized to sulfur dioxide, most of which is removed by precipitation,
although some is deposited on vegetation and available surfaces. The
resolution of the data presented here is not sufficient to permit partitioning between these two processes. The predictions presented emphasize
that productive marine environments produce large amounts of DMS. In
turn, these enhance terrestrial sulfur deposition and impact upon climatic
regimes, in particular cloud and fog physics and chemistry.
The major emphasis of this paper is to examine the role of DMS on
climate; however, additional impacts that require further consideration
include the influence of DMS on terrestrial surfaces and ecosystems. Sea
salts are the major route by which near-coastal terrestrial temperate
rainforests acquire S04' though marine emissions of DMS enhance
atmospheric inputs of sulfur (Hedin & Hetherington, this volume). The
enhancement of sulfur deposition by marine-derived DMS has also been
noted in other regions; for example, Tarrason (1991) indicated that the
seasonal variation of emissions in the North Atlantic modifies the ratio of
anthropogenic versus natural emissions and as a result affects deposition
values over Western Europe.
Conclusions
The spatial study of the eastern Pacific presented is the first known use of
a Geographic Information System (GIS) for the analysis of the DMS
feedback . It is likely that the problems associated with using spatial data
for the analysis of large-scale environmental and climatic change will
become a future feature of scientific endeavor. Spatial models are representations of reality in the same way that climatic models are, and so
although they contain and use real-world data, there are a number of
ways in which they may be used. Models can be used not only to predict
8.M.P. Benbow
components as well as measurements of DMS in the atmosphere and
oceans.
Implications for the Terrestrial Environment
Coastal zones are difficult to define and may include areas of influence
from certain selected ecological factors that extend landward and seaward
from the seashore. The features representing each domain must be characteristic of that domain, such as the primary production of ocean areas
or the extent of rainforest in terrestrial regions. For the coastal regions,
the influence of land, air, and sea features affect all ecoystems.
Sulfur deposition encompasses both dry deposition and wet deposition ,
the former as gaseous and particulate deposition and the latter determined
by precipitation. Once emitted to the atmosphere, DMS is eventually
oxidized to sulfur dioxide, most of which is removed by precipitation,
although some is deposited on vegetation and available surfaces. The
resolution of the data presented here is not sufficient to permit partitioning between these two processes. The predictions presented emphasize
that productive marine environments produce large amounts of DMS. In
turn, these enhance terrestrial sulfur deposition and impact upon climatic
regimes, in particular cloud and fog physics and chemistry.
The major emphasis of this paper is to examine the role of DMS on
climate; however, additional impacts that require further consideration
include the influence of DMS on terrestrial surfaces and ecosystems. Sea
salts are the major route by which near-coastal terrestrial temperate
rainforests acquire S04' though marine emissions of DMS enhance
atmospheric inputs of sulfur (Hedin & Hetherington, this volume). The
enhancement of sulfur deposition by marine-derived DMS has also been
noted in other regions; for example, Tarrason (1991) indicated that the
seasonal variation of emissions in the North Atlantic modifies the ratio of
anthropogenic versus natural emissions and as a result affects deposition
values over Western Europe.
Conclusions
The spatial study of the eastern Pacific presented is the first known use of
a Geographic Information System (GIS) for the analysis of the DMS
feedback . It is likely that the problems associated with using spatial data
for the analysis of large-scale environmental and climatic change will
become a future feature of scientific endeavor. Spatial models are representations of reality in the same way that climatic models are, and so
although they contain and use real-world data, there are a number of
ways in which they may be used. Models can be used not only to predict