Transport Timescales in Geophysical Flows

1. Introduction

Quantifying the transport in the stratosphere, oceans, lakes and groundwater is important for understanding/modeling the flow, biochemical cycling, distribution of constituents, and the infiltration of pollutants. An important aspect of this transport is the time for transport from the surface to interior locations. Because of mixing there is not a single surface-to-interior transit time, rather there is a distribution of transit times. These transit time distributions (TTDs) are fundamental descriptors of the transport. Although, these distributions cannot be measured directly, information on transport times can be inferred from chemical tracers with time varying sources or sinks, so called "transient tracers" . The TTD framework has been used together with tracer observations to quantify transit times in the stratosphere, Lake Issyk-Kul , and the North Atlantic Ocean . Furthermore, given estimates of TTDs it is possible to infer the infiltration of pollutants tracers into the geophysical systems, e.g., chlorine into the stratosphere and anthropogenic carbon into the oceans .


2. Transit Time Distributions


3. Transient Tracers and Tracer Ages


4. Stratosphere


5. Lake Issyk-Kul


6. North Atlantic Ocean


7. Anthropogenic Carbon in the Oceans


See papers for full details.