Chill Calculator

Introduction

This site accesses daily weather station data for the period 1968 to the current year for 600 locatons across Australia. This data is used to make calculations for the accumulation of winter chill and growing degree days/hours.

Because the chill and growing degree day calculations are based on weather data from the Long Paddock SILO, the calculations can only be updated when the weather data becomes available. The weather data from yesterday is usually available after about midday (AEST). The Long Paddock SILO uses data form the Bureau of Meterology and patches this to create complete daily data sets. Stations that no longer record temperature data are synthetically in-filled with gridded data derived from statistical analysis. The Long Paddock SILO is available here.

All calculations are performed using the chillR package of Luedeling et al. (2013) & Luedeling (2017).

Uploading Your Own Data

Datasets downloaded from your weather station need to converted to a uniform format. There are four choices for date and time - select the one that matches your data. Additional columns to the right are OK, they are ignored, but best avoided.

If you get errors you can email the data to me at Dr Neil White, Qld Dept. of Primary Industries

DateTime	Temperature
1/5/18 00:00	12.1
1/5/18 01:00	12.0
1/5/18 02:00	11.7

The names of the header columns are not important, however, the data must be in that order, date and time first column and temperature in the second column. There is very little error checking undertaken at this stage.

Hours can be 0 to 23 or 1 to 24, i.e. midnight can either be hour 0 or hour 24.

Use the checkbox Use This Data Set for Calculations to toggle between your data and the active site.

Note: Your data is not stored on the server and is destroyed when you end the session.

Selecting Locations

Locations are selected from the Locations tab by clicking the blue marker for that location on the map. Once a location has been selected, it will appear on the top left hand side of the screen. There are a number of ways to locate the blue marker you are interested in:

1. Select a growing region and wait for the map to identify the locations available for that region.
2. Search for a weather station and select from the list of responses.

Searching for a station (1 of the 600) uses a simple searching method that matches the letters entered. "ben" will match

• Bencubbin
• Bendigo Airport
• Launceston (Ti Tree Bend)


3. Selecting from the list makes this the station of interest

Searching for a locality works by matching Towns that start with the letters enetered. "ben" will match

• Benalla VIC 3672
• Bendemeer NSW 2355
• Bendigo VIC 3552
• etc...

Results do not show up until the list of possiblties is less than 200 and the selection only moves the map to that locality so that you can search for a station (blue marker)

4. Zoom in or out on the map, and pan the map to select a station.

Storing Location

If the "Remember this station" is ticked when a location marker is clicked, this becomes the default for the next time the web site is used.

The default is overwriten with subsqeuent selections.

Note: This uses a cookie to keep the information between the sessions. This stores only the station number.

Viewing the data

Once a location has been selected, simply click on the tabs for Chill, Growing Degrees or Temperature to view the graphs for that location. Once you have clicked on one of these tabs, select the year of data you want to see from the drop down menu at the top of the screen. You can also change the start date and end date by using the drop down calendars. This is particularly useful for chill graphs where you might want to calculate chill from 1 Jun, instead of 1 Mar for example. To close the calendar simply click outside of it. The graphs automatically show the data for the year selected, compared to the long-term historical record (from 1981 to 2010). When you hover your cursor over a particular spot on the graph, the values for that particular date will be flagged.

Chill Accumulation

Chilling can be calculated in either Chill Portions (Erez et al. 1990), Chill Hours (Bennet 1949, Weinberger 1950) or Chill Units (Richardson et al. 1974).

Growing Degrees

Growing Degree Hours (GDH) (Anderson et al 1974) or Growing Degree Days (GDD) are calculated when the user selects the "Growing Degrees" tab. GDH are calculated using the methodology of Anderson et al. (1986) that uses four thresholds to calculate the accumulation of yield. GDD are calculated by subtracting 10^oC (or which ever base temperature is used) from the average daily temperature. Only positive values are accumulated, i.e. temperatures greater than 10^oC. These can be accumulated from 1 January (default) or set at a later date using the date selector box. To close the calendar simply click outside of it.

Interaction with the Graph

The data presented in each of the graphical tabs, Chill, Growing Degrees and Temperature, show the average and a shaded area that represents the highest 10% and lowest 10% of years. If this is too much information click on the thick bar object that is pointing to the left. This will change from compare mode to show only the closest value. The closest value is the default in the Temperature graphs.

In the screen capture below the the graph is in compare mode, i.e. the two bars pointing left are highlighted

© State of Queensland, Department of Primary Industries and Horticulture Innovation Australia Ltd, 2024.

About This Site

This site is being developed to deliver up-to-date and historical information on the accumulation of chill and growing degree days. This work was undertaken for the project AP12029 Understanding apple and pear production systems in a changing climate funded by Horticulture Innovation Australia Limited using the Apple and Pear Industry levy and funds from the Australian Government. Additional financial support was contributed by Department of Agriculture and Fisheries (Qld), Department of Economic Development, Jobs, Transport and Resources (Vic), Department of Agriculture and Food Western Australia and Pomewest (WA). Based on or contains data provided by the State of Queensland (Department of Science, Information Technology and Innovation) [2016]. In consideration of the State permitting use of this data you acknowledge and agree that the State gives no warranty in relation to the data (including accuracy, reliability, completeness, currency or suitability) and accepts no liability (including without limitation, liability in negligence) for any loss, damage or costs (including consequential damage) relating to any use of the data. Data must not be used in breach of the privacy laws.

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If you would like further information please contact: Dr Heidi Parkes, Qld Dept. of Primary Industries For Technical issues: Dr Neil White, Qld Dept. of Primary Industries

© State of Queensland, Department of Primary Industries and Horticulture Innovation Australia Ltd, 2024