This title appears in the Scientific Report :
2011
Please use the identifier:
http://hdl.handle.net/2128/9953 in citations.
Please use the identifier: http://dx.doi.org/10.5194/acpd-11-33095-2011 in citations.
Commentary on using equivalent latitude in the upper troposphere and lower stratosphere
Commentary on using equivalent latitude in the upper troposphere and lower stratosphere
We discuss the use of potential vorticity (PV) based equivalent latitude (EqLat) and potential temperature (θ) coordinates in the upper troposphere and lower stratosphere (UTLS) for chemical transport studies. The main objective is to provide a cautionary note on using EqLat–θ coordinates for aggreg...
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Personal Name(s): | Pan, L.L. |
---|---|
Kunz, A. / Homeyer, C.R. / Munchak, L.a. | |
Contributing Institute: |
Stratosphäre; IEK-7 |
Published in: | Atmospheric chemistry and physics / Discussions, 11 (2011) |
Imprint: |
Katlenburg-Lindau
EGU
2011
|
DOI: |
10.5194/acpd-11-33095-2011 |
Document Type: |
Journal Article |
Research Program: |
Atmosphäre und Klima |
Series Title: |
Atmospheric Chemistry and Physics / Discussions
11 |
Link: |
OpenAccess OpenAccess |
Publikationsportal JuSER |
Please use the identifier: http://dx.doi.org/10.5194/acpd-11-33095-2011 in citations.
We discuss the use of potential vorticity (PV) based equivalent latitude (EqLat) and potential temperature (θ) coordinates in the upper troposphere and lower stratosphere (UTLS) for chemical transport studies. The main objective is to provide a cautionary note on using EqLat–θ coordinates for aggregating chemical tracers in the UTLS. Several examples are used to show 3-D distributions of EqLat together with chemical constituents for a range of θ. We show that the use of PV–θ coordinates may not be suitable for several reasons when tropospheric processes are an important part of a study. Due to the different static stability structures between the stratosphere and troposphere, the use of θ as a vertical coordinate does not provide equal representations of the UT and LS. Since the θ surfaces are often quasi-vertical in the troposphere, the θ coordinate does not work well distinguishing the UT from the boundary layer. We further discuss the duality of PV/EqLat as a tracer versus as a coordinate variable. Using an example, we show that while PV/EqLat serves well as a transport tracer in the UTLS region, it may misrepresent the effect of transport when used as a coordinate to average chemical tracers. Overall, when choosing these coordinates, considerations need to be made not only based on the time scale of PV being a conservative tracer, but also the specific research questions to be addressed. |