|Scott, Russell - Russ|
Submitted to: Hydrology and Earth System Sciences
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/1/2004
Publication Date: 12/1/2004
Citation: Harlow, C., Burke, E., Scott, R.L., Shuttleworth, W.J., Brown, C., Petti, J. 2004. Derivation of temperature lapse rates in semi-arid southeastern Arizona Hydrology and Earth System Sciences 8(6): 1179-1185.
Interpretive Summary: Regional ecological and hydrological modeling often requires information about the weather: e.g., precipitation, air temperature, amount of sunlight, etc. Unfortunately, these data are often only available at a few locations so reliable methods need to be developed to estimate these weather variables at other locations. This paper derives relationships that allow one to estimate maximum, minimum and mean daily air temperatures from elevation. These relationships were calculated using air temperatures collected during 2002 at eighteen locations across southeastern Arizona with elevations ranging between 779 and 2512 m. The relationship developed for the minimum temperature resulted in estimates lower than the commonly-used mean environmental lapse rate (MELR) relationship of 6 K km-1, whereas those predicted for the mean and maximum daily temperature are very similar to the MELR. Temperature-elevation relationships were also derived from weather balloon data collected at 5 pm and 5 am local time. These relationships resulted in temperatures less than those from the 2 m measurements, presumably because the surface has less effect on temperatures away from the ground. The benefits of this work will be a more accurate approach to estimate air temperatures in southeastern Arizona for the many sites and areas that do not have this information.
Technical Abstract: Ecological and hydrological modeling at the regional scale requires distributed information on weather variables, and temperature is important among these. In an area of basin and range topography with a wide range of elevations, such as southeastern Arizona, measurements are usually only available at a relatively small number of locations and elevations and temperatures elsewhere must be estimated from atmospheric lapse rate. This paper derives the lapse rates required to estimate maximum, minimum and mean daily temperatures from elevation. Lapse rates were calculated using air temperatures at 2 m collected during 2002 at eighteen locations across southeastern Arizona with elevations ranging between 779 and 2512 m. The lapse rate predicted for the minimum temperature is lower than the mean environmental lapse rate (MELR), i.e. 6 K km-1, whereas those predicted for the mean and maximum daily temperature are very similar to the MELR. Lapse rates were also derived from radiosonde data collected at 00 and 12 UTC (5 pm and 5 am local time, respectively). The lapse rates calculated from radiosonde data are greater than those from the 2 m measurements, presumably because the surface effect have less effect. Given temperatures measured at Tucson airport, temperatures at the other sites were predicted using the different lapse rate estimates. The best predictions of temperatures used the locally predicted lapse rate. In the case of maximum and mean temperature, using the MELR also results in accurate predictions.