TRACE A trajectory intercomparison: 2. Isentropic and kinematic methods ...

• Main Authors: Fuelberg, Henry E., Loring Jr., Robert O., Watson, Mark V., Sinha, M. C., Pickering, Kenneth E., Thompson, Anne M., Sachse, Glen W., Blake, Donald R., Schoeberl, Mark R.
• Format: Text
• Language: English
• Published: AGU 1996
• Subjects: South Atlantic Ocean
• Online Access: https://dx.doi.org/10.13016/m2ttgu-tiyj; https://mdsoar.org/handle/11603/35159

Kinematic and isentropic trajectories are compared quantitatively during a single 5-day period (October 13–18, 1992) when several flights for the Transport and Atmospheric Chemistry Near the Equator-Atlantic (TRACE A) experiment were conducted off the west coast of Africa. European Centre for Medium-Range Weather Forecasts (ECMWF) data are used to compute the 5-day backward trajectories arriving at locations over the South Atlantic Ocean and nearby parts of South America and southern Africa. Two versions of kinematic trajectories are examined. One version employs vertical motions supplied with the ECMWF data. These trajectories often differ greatly from those based on the isentropic assumption. The kinematic trajectories usually undergo considerably greater vertical displacements than their isentropic counterparts; however, most diabatic rates are consistent with those of synoptic-scale systems. Ratios of acetylene to carbon monoxide are related to backward trajectories at various locations along a TRACE A ...