Copying this over from the Melting thread.
In the past few days, temperatures at Eureka have skyrocketed. As they have over much of the CAA.
Eureka looks like shattering some old records. My first thoughts, when Oren put up the chart from Ogimet was that Eureka looked way too high.
No need to doubt, the CAA has quite a few weather stations and you can view daily and even hourly temperatures online. Here's a map showing these weather stations and the max temps (C, not F) for June 26th. Sweltering indeed.
No doubt some very warm temperatures. But I was a bit taken back by the Eureka temperature shown which is very close to record June temperature.
Closer inspection on weatherobs website shows there are synops from 2 sites at Eureka.
71917 and 71613
At time of posting 71917 is showing 17 C (following a supposed record June max of 19.1 C) while 71613 is showing 8 C following a max of 12.3 C.
Big difference over a short distance.
Going especially by the Tmins I think the data from 71917 is totally wrong.
could be be an elevation difference?
The problem at Eureka is that there are two temperature stations. Let's call them Eureka Climate and Eureka Airport. They are located about 2 km apart.
Comparison between the two stations has shown a difference of over 8 C between the two with Eureka climate, the one nearest the inlet being the cooler of the two.
Friv raised the question is there an elevation difference ? Ogimet give both at 10m but this is not correct. There is a sign at the airport indicating the elevation there is 256 ft.
The questions then are :
1) Is there something inherently wrong with the data from the airport eg sensor malfunction and/or incorrect exposure ?
or
2) Is this a feature of the unique climate of this high Arctic inlet?
Hopefully Environment Canada will be able to shed some light on this. But 2) is an interesting proposition, what could be happening to allow such a big differential over a shot distance ? Some thoughts:
* There is no night period as this lattitude at this time of the year. The sun's elevation goes from 13 deg to 33 deg
* The inlet is still frozen solid.
* As mentioned already one station is circa 10m near the frozen inlet and the other circa 78m. There is little or no snow now in the immediate vicinity. It is just bare earth or rock.
* The wind direction over the past few days has been predominantly westerly.
* Humidity is a lot lower at the airport station (due to the higher dry bulb temps) but dew points are quite similar.
* The airport station in particular has been slow to cool down as the sun descends in the sky. Minimum on the 28th was 12.1 C versus 3.3 C at the climate station.
The bare terrain of course would not help to radiate heat to space and maybe the nearby frozen ice surface would help the climate station to cool, with the west wind fanning cooler air from the inlet.
It is a surprise to me that there would be such large differences but maybe it can be explained by the ice, bare earth, wind and topography.
It does remind me of the remarkable climate of Kangerlussuaq in western Greenland which frequently records high temperatures of 20 C or more.
But Eureka is further north.
This year too in Siberia has seen some incredible temperatures. As the heat moves further north, dramatic changes will occur the further north you go. The sun does not set and there is plenty of dark bodies to absorb the incoming solar radiation.
A taster of what it will be like when the summer sea ice goes ?
